'''
A module for reading, handling, and plotting RAM-SCB output.
'''

# Global imports
import datetime as dt

import numpy as np
import scipy.io

import spacepy.datamodel as dm
import spacepy.time as spt
import spacepy.toolbox as tb
from spacepy.plot import set_target, applySmartTimeTicks
from spacepy.pybats import PbData


#  Start module with a few useful functions:
def gen_rgrid(nR=20, rmin=1.75, rmax=6.5):
    '''
    Given the number of radial points, *nR*, the min and max of the radial
    extent, *rmin* and *rmax*, repsectively, create and return the radial grid
    of RAM-SCB as a vector of points in Earth radii.

    Note that the first and last cells are ghost cells.
    '''
    r = np.zeros(nR+1)
    dR = (rmax-rmin)/(nR-1)
    for i in range(nR+1):
        r[i] = rmin+i*dR
    return r


def gen_tgrid(nT=25):
    '''
    Given the number of local time grid points, *nT*, return, as vectors,
    the grid points in local time in units of radians and then local time hours
    that would be used in RAM-SCB.
    '''
    lt = np.zeros(nT)
    dT = 24.0/(nT-1)
    phi = np.zeros(nT)
    dp = np.pi/(nT-1)*2.0
    for i in range(nT):
        lt[i] = dT*i
        phi[i] = dp*i
    return phi, lt


def gen_egrid(nE=36, lb=0.1, ew=3E-2, power=1.27):
    '''
    Given number of points and a lower boundary (*nE* and *lb*), build the
    RAM-SCB energy grid.  Three arrays are returned: ebound(nE+1), the boundary
    of each bin, ecenter(nE), the center of each bin, and ewidth(nE),
    the width of each bin.  All output units are in keV.

    Grid parameters can be set with kwargs but default to common RAM values:
    ======= =========================================
    Kwarg   Description
    ======= =========================================
    nE      Number of grid points.
    lb      Lower boundary of energy grid in keV
    ew      Width of first energy bin.
    power   Power series exponent to determine grid spacing.
    ======= =========================================


    Usage:

    >>> (ecentr, ebound, ewidth)=gen_egrid(nE=36, lb=0.1, ew=3E-2, power=1.27)

    '''

    ebound = np.zeros(nE+1)
    ecentr = np.zeros(nE)
    ewidth = np.zeros(nE)

    ebound[0] = lb
    ewidth[0] = ew
    ecentr[0] = ebound[0] + 0.5*ewidth[0]
    for i in range(nE-1):
        ewidth[i+1] = ewidth[i]*power
        ebound[i+1] = ebound[i] + ewidth[i]
        ecentr[i+1] = ecentr[i] + 0.5*(ewidth[i+1] + ewidth[i])
    ebound[-1] = ebound[-2] + ewidth[-1]

    return (ecentr, ebound, ewidth)


def young_comp(kp, f107):
    '''
    Determine plasma sheet composition using the Young et al. empirical
    relationship based on Kp and F10.7 (first and second arguments,
    respectively) as given by *Young et al.* [JGR, 1982, Vol. 87 No. A11]

    Returns fraction of total number density that is Hydrogen,
    Helium, and Oxygen.

    Example usage:

    >>> FracH, FracHe, FracO = young_comp(5, 150.0)

    '''
    ratOH = 4.5E-2 * np.exp(0.17*kp + 0.01*f107)  # +/-0.21; Eq. 5, pg. 9088
    ratHeH = 0.618182*ratOH*np.exp(-0.24*kp - 0.011*f107) + 0.011*ratOH
    fracH = 1.0 / (1.0 + ratHeH + ratOH)
    fracHe = ratHeH * fracH
    fracO = ratOH * fracH

    return fracH, fracHe, fracO


def viz_young_comp():
    '''
    Create a quick-look plot of % O+ as calculated by Young et al. for
    various values of Kp and F10.7.  No input arguments are taken.
    '''
    import matplotlib.pyplot as plt
    from matplotlib.ticker import MultipleLocator

    kp = np.arange(0, 9.1, 0.1)
    f7 = np.arange(0, 301, 1.0)
    fracH = np.zeros((kp.size, f7.size))
    fracO = np.zeros((kp.size, f7.size))
    fracHe = np.zeros((kp.size, f7.size))

    for i, f in enumerate(f7):
        fracH[:, i], fracHe[:, i], fracO[:, i] = young_comp(kp, f)

    levs = np.linspace(0, 0.8, 50)
    fig = plt.figure()
    ax2 = fig.add_subplot(111)
    cnt2 = ax2.contourf(f7, kp, fracO, levs)
    ax2.set_title('Young et al. Fraction O$^{+}$')
    ax2.set_xlabel('F10.7 Flux')
    ax2.set_ylabel('Kp Index')
    cb2 = plt.colorbar(cnt2, ticks=MultipleLocator(0.1))
    cb2.set_label('Fraction O$^{+}$')
    ax2.grid()

    if plt.isinteractive():
        plt.draw()
    else:
        plt.show()


def viz_egrid(nE=36, lb=0.1, ew=3E-2, power=1.27):
    '''
    Vizualize the RAM-SCB energy grid.  All kwargs correspond to those used by
    :func:`gen_egrid`.
    '''
    import matplotlib.pyplot as plt

    ecent, ebound, ewidth = gen_egrid(nE, lb, ew, power)
    y = np.zeros(len(ecent))

    fig = plt.figure(figsize=(12, 4))
    fig.subplots_adjust(bottom=0.1, right=0.98, left=0.02)
    ax = fig.add_subplot(111)

    ax.errorbar(ecent, y, fmt='r', xerr=ewidth/2.0, label='Bin Widths',
                ecolor='r', elinewidth=3, capsize=30)
    ax.plot(ecent, y, 'g*', label='Bin Centers')
    ax.legend()
    ax.set_title('RAM-SCB Energy Grid - Power=%4.2f' % power)
    ax.set_xlabel('Energy ($KeV$)')
    ax.set_yticklabels([])
    ax.set_xlim([ebound[0]-20.0, ebound[-1]+20.0])
    ax.set_ylim([-1, 1])


def gen_pgrid(nPa=72):
    '''
    Given number of points, *nPa*, build the RAM-SCB pitch angle grid.
    The return value is a *nPa*x3 matrix containing the bin starts, centers,
    and ends in cosine of pitch angle.
    '''
    pgrid = np.zeros((nPa, 3))


def read_t89file(filename):
    '''
    Read a T89 input file intended for RAM-SCB.

    Usage:

    >>> time, b_dip, b_ext = read_t89file('somefile.t89')

    '''
    infile = open(filename, 'r')
    raw = infile.readlines()
    raw.pop(0)  # skip header.

    nRec = len(raw)
    time = []
    bdip = np.zeros((nRec, 3))
    bext = np.zeros((nRec, 3))

    for i, line in enumerate(raw):
        parts = line.split()
        time.append(dt.datetime(int(parts[0]),
                                int(parts[1]),
                                int(parts[2]),
                                int(parts[3]),
                                int(parts[4]),
                                int(parts[5])
                                )
                    )
        bdip[i, :] = (float(parts[6]), float(parts[7]), float(parts[8]))
        bext[i, :] = (float(parts[9]), float(parts[10]), float(parts[11]))

    return time, bdip, bext


def grid_zeros(axis):
    '''
    Attempt to plot x=0 and y=0 gridlines w/o messing up
    plot range.  This should be called last when creating
    a plot; after you have the range sorted out.
    '''
    axis.axvline(0, ls='-', color='k')
    axis.axhline(0, ls='-', color='k')


def set_orb_ticks(axis):
    '''
    Set major ticks to multiples of 1, minor ticks to 1/4.
    '''
    from matplotlib.ticker import MultipleLocator

    # Tick Locators:
    xMticks = MultipleLocator(2.00)
    xmticks = MultipleLocator(0.5)
    yMticks = MultipleLocator(2.00)
    ymticks = MultipleLocator(0.5)
    axis.xaxis.set_major_locator(xMticks)
    axis.xaxis.set_minor_locator(xmticks)
    axis.yaxis.set_major_locator(yMticks)
    axis.yaxis.set_minor_locator(ymticks)
    axis.grid(True)


def add_body(ax, rad=2.0, rotate=0.0, add_night=True, **extra_kwargs):
    '''
    Creates a circle of radius kwarg rad (default 2.0 RE) at the center of
    axis ax.  Then, a planet of radius 1.0 RE is added to the center to
    represent the Earth.  Extra kwargs are passed to the patch generators.

    Three patches are created by this function: the inner boundary (a light
    grey Circle patch), the planet (a white Circle patch) and the night side
    of the planet (a black wedge.)  All three are returned to the caller.

    The kwarge "rotate", which defaults to 0.0, can be set to any angle
    (in degrees) to rotate the location of local noon/midnight on the
    planet patches.  The default is local noon points towards +X.  A
    rotate value of 90 will cause local noon to point towards +Y.

    Example

    >>>ax=pylab.subplot(111)
    >>>inner, planet, night = rampy.add_body(ax)

    If you are using a polar axis, try using add_body_polar.
    '''

    from matplotlib.patches import Circle, Wedge

    inner = Circle((0, 0), rad, fc='lightgrey', ec='k', zorder=1000,
                   **extra_kwargs)
    planet = Circle((0, 0), 1.0, fc='w', zorder=1001, **extra_kwargs)
    night = Wedge((0, 0), 1.0, 90+rotate, -90+rotate, fc='k',
                  zorder=1002, **extra_kwargs)

    ax.add_artist(inner)
    ax.add_artist(planet)
    if add_night:
        ax.add_artist(night)

    return inner, planet, night


def add_body_polar(ax, noon=90.0):
    '''
    Add the "Earth" to the center of a polar dial plot located on
    axis "ax".  Kwarg noon specifies the angle counter clockwise from the
    x-axis, in degrees, that is local noon (e.g. sun facing.)  Default is
    90 degrees, or in the +Y direction.
    '''
    from matplotlib.patches import Polygon

    # Number of points:
    nPts = 101

    # Convert "noon" to radians.
    noon = np.pi*noon/180.0

    # First, a circle.
    x = np.linspace(0., 2.0*np.pi, nPts)  # Polar angle.
    y = np.zeros(nPts) + 1.0              # Polar radius.
    circ = Polygon(np.array([x, y]).transpose(), fc='w', ec='k', zorder=1001)

    # Now, nightside.
    x = np.linspace(noon+np.pi/2.0, noon+3.0*np.pi/2.0, nPts)
    arc = Polygon(np.array([x, y]).transpose(), fc='k', ec='k', zorder=1002)

    # Add to plot.
    ax.add_artist(circ)
    ax.add_artist(arc)


def _adjust_dialplot(ax, rad, title='Noon', labelsize=15, c='gray'):
    '''
    Ram output is often visualized with equatorial dial plots.  This
    function quickly adjusts those plots to give a uniform, clean
    look and feel.
    '''
    from matplotlib.ticker import MultipleLocator
    # Constrain range of plot:
    ax.set_ylim([0, np.max(rad)])
    # Set MLT labels:
    lt_labels = ['06', title, '18', '00']
    xticks = [0, np.pi/2, np.pi, 3*np.pi/2]
    ax.set_xticks(xticks)
    ax.set_xticklabels(lt_labels)
    ax.tick_params('x', labelsize=labelsize)
    # Set L labels and grid.  Turn off label at L=0.
    ax.yaxis.set_major_locator(MultipleLocator(2))
    labels = ax.get_yticklabels()
    labels[0].set_visible(False)
    ax.tick_params('y', labelcolor=c, labelsize=labelsize)
    ax.grid(True, c=c, lw=1, ls=':')
    # Change background color so labels stand out.
    ax.set_facecolor('gray')
    add_body_polar(ax)


def get_iono_cb(ct_name='bwr'):
    '''
    Several custom colorbars used by RIM and AMIE have become standard when
    visualizing data from these models.  These are 'blue_white_red' and
    'white_red', used for data that have positive and negative values and
    for data that have only positive values, respectively.  This function
    builds and returns these colorbars when called with the initials of the
    color table name as the only argument.

    For RAM-SCB usage, the 'bwr' color map is useful for plotting ionospheric
    potential and will create plots that look similar to those produced by
    AMIE and RIM.  The 'wr' color map is useful when plotting anisotropy.

    Example - get each colormap:

    >>>bwr_map = get_iono_cb('bwr')
    >>>wr_map  = get_iono_cb('wr')
    '''
    from matplotlib.colors import LinearSegmentedColormap as lsc

    if ct_name == 'bwr':
        table = {'red': [(0, 0, 0), (0.34, 0, 0), (0.5, 1, 1), (1, 1, 1)],
                 'green': [(0, 0, 0), (0.35, 1, 1), (0.66, 1, 1), (1, 0, 0)],
                 'blue': [(0, 1, 1), (0.5, 1, 1), (0.66, 0, 0),
                          (0.85, 0, 0), (1, 0.1, 0.1)]
                 }
        cmap = lsc('blue_white_red', table)
    elif ct_name == 'wr':
        table = {'red': [(0, 1, 1), (1, 1, 1)],
                 'green': [(0, 1, 1), (1, 0, 0)],
                 'blue': [(0, 1, 1), (1, 0, 0)]
                 }
        cmap = lsc('white_red', table)

    return cmap


class EfieldFile(PbData):
    '''
    Base class for reading electric field input and output ASCII files.
    Subclasses such as WeqFile are customized to handle specific formats.

    The default object is configured to handle
    '''
    def __init__(self, filename, *args, **kwargs):
        # Init base object.
        super(EfieldFile, self).__init__(*args, **kwargs)

        # Stash file name and read:
        self.attrs['file'] = filename
        self.read()

    def _parse_head(self, fileobj):
        '''
        The function to parse the header should obtain:
        1) The date and time
        2) Relevant indices

        For input, pass the file object.  Header lines will be
        read such that only the value names and data are left to
        be read.
        '''

        head1 = fileobj.readline()
        head2 = fileobj.readline()
        formatms = 'Date=%Y-%m-%d_%H:%M:%S.000'
        formats = 'Date=%Y-%m-%d_%H:%M:%S'
        tstr = head1.split()[-1]
        try:
            self.attrs['time'] = dt.datetime.strptime(tstr,
                                                      formatms)
        except ValueError:
            self.attrs['time'] = dt.datetime.strptime(tstr,
                                                      formats)

        self.attrs['kp'] = float(head2.split()[1])
        self.attrs['f107'] = float(head2.split()[-1])
        # Original code: works with weimer files:
        # parts= headlines.split()
        # self.doy = int(parts[0])
        # self.hour= float(parts[1])
        # self.time = dt.datetime(year, 1,1,0,0) + \
        #             dt.timedelta(days=doy-1) + \
        #             dt.timedelta(hours=hour)

    def read(self):
        '''
        Load and parse the information in the file.
        '''

        # Open file object.  Send object to header parser.
        infile = open(self.attrs['file'], 'r')
        self._parse_head(infile)

        # Save last header line:
        head = infile.readline()

        # Slurp rest of lines:
        raw = infile.readlines()

        # Create containers.  Note that we don't know if the file
        # contains longitude or MLT at this point...
        self['epot'] = dm.dmfilled(len(raw), attrs={'units': 'keV'})
        self['l'] = dm.dmfilled(len(raw), attrs={'units': 'Re'})
        mlt = dm.dmfilled(len(raw))

        for i, line in enumerate(raw):
            parts = line.split()
            self['l'][i] = parts[0]
            mlt[i] = parts[1]
            self['epot'][i] = parts[2]

        # Use header to determine if we have MLT or Phi.
        # Calculate the one we don't have.
        if 'mlt' in head.lower():
            self['mlt'] = mlt
            self['phi'] = self['mlt']*np.pi/12.0
        else:
            self['phi'] = mlt
            self['mlt'] = self['phi']*12/np.pi

        # Make CPCP
        self.attrs['cpcp'] = self['epot'].max() - self['epot'].min()

        infile.close()

    def add_potplot(self, target=None, loc=111, zlim=50, n=31, figsize=(5, 4),
                    add_cbar=True, labcolor='lightgray', title='Noon'):
        '''
        Quickly add a potential plot to MPL object *target*.

        Parameters
        ==========

        Other Parameters
        ================
        target : object
           The object on which plotting will happen.
        figsize : tuple
           A two-item tuple/list giving the dimensions of the figure, in inches.
           Defaults to (5,4)
        loc : integer
           The subplot triple that specifies the location of the axes object.
           Defaults to 111.
        zlim : real
           The upper limit for the color bar range.  Defaults to 50.
        n : int
           The number of contours.  Defaults to 31.
        labcolor : color
           A matplotlib-compatable color indicator for the ticks and labels.
        title : string
           A string title to set at the top of the plot.  Defaults to "Noon".
        '''
        import matplotlib.pyplot as plt
        from matplotlib.colors import Normalize
        from matplotlib.ticker import MultipleLocator

        fig, ax = set_target(target, figsize=figsize, loc=loc, polar=True)

        cmap = get_iono_cb('bwr')
        crange = Normalize(vmin=-1.*zlim, vmax=zlim)
        levs = np.linspace(-1*zlim, zlim, n)

        cont = ax.tricontourf(self['phi']-np.pi/2.0, self['l'],
                              np.asarray(self['epot']),
                              levs, norm=crange, cmap=cmap)
        _adjust_dialplot(ax, self['l'], c=labcolor, title=title)
        cbar = False
        if add_cbar:
            cticks = MultipleLocator(25)
            cbar = plt.colorbar(cont, ticks=cticks, shrink=0.8, pad=0.08)
            cbar.set_label('kV')

        return fig, ax, cont, cbar


class WeqFile(EfieldFile):
    '''
    Slight variation on :class:`weimer` to read weq_***.in files.
    '''
    def _parse_head(self, headlines):
        parts = headlines.split()
        self.UT = float(parts[0])


class RamSat(PbData):
    '''
    A class to handle and plot RAM-SCB virtual satellite files.  Instantiate
    an object by simply calling:

    >>>sat=rampy.RamSat('SatFile.nc')

    Simple satellite file info, such as the time vector, file name, and
    output frequency are found as direct object attributes:

    >>>sat.time
         array([2005-08-31 09:29:00, ...,2005-09-02 00:58:00],dtype=object)

    Data arrays are stored as object keys.  For example, obtain satellite
    coordinates by typing:

    >>>sat['SM_xyz']

    RamSats work, for the most part, like dictionaries.  Add a new data entry
    (an array, constant, etc.) by simply calling:

    >>>sat['New Thing']=(0,1,2,3,4)

    Be sure to peruse the docstrings of the many object methods to discover
    the many plotting functions and other capabilities.
    '''
    def __init__(self, filename):
        # Filename:
        super(RamSat, self).__init__()
        self.filename = filename
        self._read()

    def _read(self):
        '''
        Load the NCDF file.  Should only be called by __init__().
        '''
        self.f = scipy.io.netcdf_file(self.filename, mode='r', mmap=False)
        self.namevars = list(self.f.variables.keys())
        # split off the netCDF attributes from the Python attributes
        for k in dir(self.f):
            if k[0] == '_' or k in ('dimensions', 'filename', 'fp', 'mode',
                                    'use_mmap', 'variables', 'version_byte'):
                continue
            tmp = getattr(self.f, k)
            if not callable(tmp):
                self.attrs[k] = tmp

        for var in self.f.variables:
            self[var] = dm.dmarray(self.f.variables[var][...])

        # Get start time, set default if not found.
        try:
            stringtime = self.attrs['start_time'].decode()
        except KeyError:
            stringtime = '20000101000000'

        # parse start time and use it to create time object.
        self.starttime = dt.datetime.strptime(stringtime, '%Y%m%d%H%M%S')

        # Convert time in seconds to datetime.
        secs = self.f.variables['Time'][...]
        self.time = np.array(
            [self.starttime + dt.timedelta(seconds=float(s)) for s in secs])
        self['Time'] = self.time

        # Close netcdf file and remove reference
        self.f.close()
        del self.f

        # Some other variables to keep handy:
        try:
            self.dt = self['DtWrite']
        except KeyError:
            # Old files do not have DtWrite.
            self.dt = np.diff(self.time).min()

    def create_omniflux(self, check=True):
        '''
        Integrate the flux(currently as a function of energy and
        pitch angle) to get omnidirectional flux as a function of
        energy.  New units = (cm-2*s*keV)^-1

        Usage: just call this method to integrate all species.

        Other Parameters
        ================
        check : Boolean
                If check is True (default) then the presence of existing
                omni variables will cause this calculation to abort cleanly.
                If check is False, anything pre-calculated will be overwritten.
        '''
        def get_species_label(keyname, omni=False):
            uvar = 'omni' if omni else 'Flux'
            if keyname.startswith(uvar + '_'):
                return keyname[len(uvar)+1:].replace('+', '').replace('-', '')
            elif keyname.startswith(uvar):
                return keyname[len(uvar):].replace('+', '').replace('-', '')

        omnipresent = [True for kk in self if get_species_label(kk, omni=True)
                       is not None]
        if check and omnipresent:
            return None
        # Create new flux attributes:
        nTime = self.time.size
        nPa = self['pa_grid'].size
        nEner = self['energy_grid'].size
        omnikeys = [('omni{0}'.format(get_species_label(kk)), kk)
                    for kk in self if get_species_label(kk) is not None]
        # Create delta mu, where mu = cos(pitch angle)
        if 'pa_width' not in self:
            # if "pa_width" absent, calculate...
            # assume bin width for zeroth bin is same as first,
            # and that zeroth PA is zero.
            grdif = np.diff(self['pa_grid'])
            self['pa_width'] = dm.dmarray(np.r_[grdif[0], grdif])
        dMu = 4*np.pi*self['pa_width']

        for omkey, fluxkey in omnikeys:
            self[omkey] = np.zeros((nTime, nEner))
            # Integrate.
            temp = np.ma.masked_where(self[fluxkey] <= 0, self[fluxkey])
            self[omkey] = (temp * np.reshape(dMu, (1, -1, 1))).sum(axis=1)

            # Mask out bad values.
            self[omkey] = np.ma.masked_where(self[omkey] <= 0, self[omkey])

    # RamSat Viz Routines #
    def _orbit_formatter(self, x, pos):
        '''
        A function that, when passed to the FuncFormatter class of
        Matplotlib tick formatters, produces specialized ticks that give
        UT, LT, and inclination.
        '''

        from matplotlib.dates import num2date

        nt = num2date(x, tz=None)
        nowtime = dt.datetime(  # Need "naive" dt object.
            nt.year, nt.month, nt.day, nt.hour, nt.minute,
            nt.second, tzinfo=None)
        deltime = (self.time-nowtime)
        mintime = min(abs(deltime))
        try:
            index = (deltime.tolist()).index(mintime)
        except ValueError:
            # Build format string.
            fmtstring = \
                '%02d:%02d UT\n* MLT\n* MLat\nR=*$R_{E}$' % \
                (nowtime.hour, nowtime.minute)
            return(fmtstring)

        # Get local time from XY coords.
        x = self['SM_xyz'][index, 0]
        y = self['SM_xyz'][index, 1]
        z = self['SM_xyz'][index, 2]
        R = np.sqrt(y**2 + x**2 + z**2)
        Mlat = np.rad2deg(np.arcsin(z/R))
        fltMLT = tb.rad2mlt(np.arctan2(y, x)) % 24
        locHr = np.floor(fltMLT).astype(int)
        locMn = np.round((fltMLT - locHr)*60).astype(int)

        # Build format string.
        fmtstring = \
            '%02d:%02d UT\n%02d:%02d MLT\n%5.1f$^{\circ}$ MLat\nR=%4.2f $R_{E}$'\
            % (nowtime.hour, nowtime.minute, locHr, locMn, Mlat, R)

        return (fmtstring)

    def add_orbit_plot(self, plane='XY', target=None, timelim=False, loc=111,
                       ls='g.', title=False, invertX=True):
        """
        Add a simple, 2D plot of the satellite orbit in a given (SM) plane.

        Other Parameters
        ================
        plane : string
             Plane to plot. Options are 'XY', 'XZ', and 'YZ'; defaults 'XY'.

        target : Figure or Axes
             If None (default), a new figure is generated from scratch.
             If a matplotlib Figure object, a new axis is created
             to fill that figure.
             If a matplotlib Axes object, the plot is placed
             into that axis.

        loc : int
            Use to specify the subplot placement of the axis
            (e.g. loc=212, etc.) Used if target is a Figure or None.
            Default 111 (single plot).

        invertX : boolean
            Reverse the SM X axis so "Sun is to the left." Default True.
            This reverses the SM axis, not the plot axis, so it has no effect
            if plane is YZ.

        timelim : tuple
             A tuple of two :class:`datetime.datetime` objects specifying the
             time range to be plotted.  Defaults to **None** such that the
             whole time range available is plotted.

        title : string
             Sets title for plot axes.

        ls : string
             A matplotlib-compatable line format specifier, e.g., 'b-'.
             Defaults to 'g.', or green dots.
        """
        if not plane.upper() in ('XY', 'XZ', 'YZ'):
            raise ValueError("{0} is not a valid plot plane.".format(plane))

        fig, ax = set_target(target, loc=loc, figsize=(5, 5))

        # Variables to map plot plane to correct variables:
        plane = plane.upper()
        ijk = {'X': 0, 'Y': 1, 'Z': 2}
        i = ijk[plane[0]]
        j = ijk[plane[1]]

        if not timelim:
            # Set default time limit if none given.
            timelim = [self.time[0], self.time[-1]]
            iMin = 0
            iMax = -1
        else:
            # Use timelim to get indices that bound our plots.
            timediff = abs(self.time - timelim[-1])
            iMax = np.nonzero(timediff == timediff.min())[0][0]
            timediff = abs(self.time - timelim[0])
            iMin = np.nonzero(timediff == timediff.min())[0][0]

        # Add orbit:
        ax.plot(self['SM_xyz'][iMin:iMax, i],
                self['SM_xyz'][iMin:iMax, j],
                ls)
        # Add body:
        add_body(ax, add_night=(plane != 'YZ'))

        # Axis details:
        ax.axis('equal')
        if plane.upper() in ('XY', 'XZ') and invertX:
            xmin, xmax = ax.get_xlim()
            if xmin < xmax:
                ax.invert_xaxis()
        ax.set_xlabel('SM %s' % (plane[0]))
        ax.set_ylabel('SM %s' % (plane[1]))
        if title:
            ax.set_title(title)
        grid_zeros(ax)
        set_orb_ticks(ax)

        return fig, ax

    def add_omniflux_plot(self, nameflux, target=None, zlim=[1E4, 1E9],
                          add_cbar=True, do_orbticks=False, title=False,
                          timelim=False, loc=111, no_xlabels=False):
        """
        Create and place a pcolor-type plot of omnidirectional flux.

        Omnidirectional fluxes are calculated by the object method
        "create_omniflux" and are saved into the object with keys such as
        'omniO' and 'omniHe', etc.

        Other Parameters
        ================
        target : Figure or Axes
             If None (default), a new figure is generated from scratch.
             If a matplotlib Figure object, a new axis is created
             to fill that figure.
             If a matplotlib Axes object, the plot is placed
             into that axis.

        loc : int
            Use to specify the subplot placement of the axis
            (e.g. loc=212, etc.) Used if target is a Figure or None.
            Default 111 (single plot).

        do_orbticks : boolean
            Activate orbit ticks (default False): add complex but
            informational tick marks that list the satellite's coordinates
            along with the time on the x-axis.  However, using these will
            require some "massaging" of the plot to make them properly
            visible.  Be sure to add lots of padding to the bottom of the plot.

        no_xlabels : boolean
            (Default False) Completely omit xlabel and xticklabels.
            Convenient for stacking flux plots on each other.
        """

        import matplotlib.pyplot as plt
        from matplotlib.colors import LogNorm
        from matplotlib.ticker import (FuncFormatter, LogLocator,
                                       LogFormatterMathtext)
        from matplotlib.dates import date2num

        fig, ax = set_target(target, loc=loc, figsize=(10, 4))

        # Check for omni fluxes, calculate as necessary.
        if nameflux not in self:
            self.create_omniflux()
            if nameflux not in self:
                raise KeyError('%s is not a valid omnidirectional flux.'
                               % nameflux)
        # Create a time vector that binds each pixel correctly.
        time = np.zeros(self.time.size+1)
        time[0] = date2num(self.time[0]-dt.timedelta(seconds=self.dt/2.0))
        time[1:] = date2num(self.time+dt.timedelta(seconds=self.dt/2.0))
        # egrid = self['energy_grid']
        ecenter, eboundary, ewidth = gen_egrid(nE=self['energy_grid'].size)
        # print("Need better energy grid setup for pcolormesh.")
        flx = ax.pcolormesh(time, eboundary,
                            np.asarray(self[nameflux]).transpose(),
                            norm=LogNorm(vmin=zlim[0], vmax=zlim[1]))
        ax.set_yscale('log')
        ax.set_ylim([eboundary[0], eboundary[-1]])
        if not timelim:
            timelim = [self.time[0], self.time[-1]]
        applySmartTimeTicks(ax, timelim, dolabel=True)
        if no_xlabels:
            ax.set_xlabel('')
            ax.set_xticklabels([''])
            do_orbticks = False
        ax.set_ylabel('E ($keV$)')
        if title:  # If title not set, use a default:
            ax.set_title(title)
        else:
            labels = {'omniH': 'H$^{+}$', 'omniHe': 'He$^{+}$',
                      'omniO': 'O$^{+}$', 'omnie': 'e$^{-}$'}
            ax.set_title('Omnidirectional %s Flux' % (labels[nameflux]))
        if do_orbticks:
            ax.xaxis.set_major_formatter(FuncFormatter(self._orbit_formatter))
        if add_cbar:
            cbar = plt.colorbar(flx, pad=0.01, shrink=.85, ticks=LogLocator(),
                                format=LogFormatterMathtext(), ax=ax)
            cbar.set_label('$cm^{-2}s^{-1}keV^{-1}$')
        else:
            cbar = False

        return fig, ax, flx, cbar

    def plot_omni_quicklook(self, flux_opts=None, eflux_opts=None,
                            hflux_opts=None, oflux_opts=None):
        """
        Create a quick-look plot of omnidirectional fluxes.

        Other Parameters
        ================
        flux_opts : dict
            dictionary of keyword arguments to pass to
            :meth:`add_omniflux_plot` for all flux plots

        eflux_opts : dict
            as flux_opts, but for the electron flux plot only

        hflux_opts : dict
            as flux_opts, but for the H+ flux plot only

        oflux_opts : dict
            as flux_opts, but for the O+ flux plot only

        Returns
        =======
        out : Figure
            Has 9 axes instances (axes attribute)
            0: XY orbit plot
            1: XZ orbit plot
            2: YZ orbit plot
            3: e- flux
            4: H+ flux
            5: O+ flux
            6: e- flux color bar
            7: H+ flux color bar
            8: O+ flux color bar
        """
        import matplotlib.pyplot as plt
        import matplotlib.gridspec as gridspec

        fig = plt.figure(figsize=(11, 7))
        fig.subplots_adjust(left=0.07, right=0.99, bottom=0.19,
                            top=0.94, wspace=0.4, hspace=0.25)
        gs = gridspec.GridSpec(3, 3)

        # Do orbits first.
        a1 = fig.add_subplot(gs[0, 0])
        a2 = fig.add_subplot(gs[1, 0])
        a3 = fig.add_subplot(gs[2, 0])
        self.add_orbit_plot('XY', target=a1)
        self.add_orbit_plot('XZ', target=a2)
        self.add_orbit_plot('YZ', target=a3)

        # Add fluxes.
        a1 = fig.add_subplot(gs[0, 1:])
        a2 = fig.add_subplot(gs[1, 1:])
        a3 = fig.add_subplot(gs[2, 1:])
        if eflux_opts is None:
            eflux_opts = {}
        if hflux_opts is None:
            hflux_opts = {}
        if oflux_opts is None:
            oflux_opts = {}
        if flux_opts is None:
            flux_opts = {}
        for k in flux_opts:
            for d in (eflux_opts, hflux_opts, oflux_opts):
                if k not in d:
                    d[k] = flux_opts[k]
        self.add_omniflux_plot('omnie', target=a1, no_xlabels=True,
                               **eflux_opts)
        self.add_omniflux_plot('omniH', target=a2, no_xlabels=True,
                               **hflux_opts)
        self.add_omniflux_plot('omniO', target=a3, do_orbticks=True,
                               **oflux_opts)

        return fig


class PlasmaBoundary(PbData):
    '''
    Opens an ascii-format boundary file written from
    IM_wrapper.f90:IM_put_from_gm in the coupled SWMF-RAM-SCB model.
    '''

    def __init__(self, filename, time=None, *args, **kwargs):
        # Init base object.
        super(PlasmaBoundary, self).__init__(*args, **kwargs)

        # Set up this instance:
        self.attrs['file'] = filename
        self.read(time)

    def read(self, time=None):
        '''
        Read and parse the ascii boundary file.
        '''
        # Read contents, slurp.
        infile = open(self.attrs['file'], 'r')
        raw = infile.readlines()
        infile.close()

        # First line of header has date and time.
        if time:
            self.attrs['time'] = time
            raw.pop(0)
        else:
            parts = raw.pop(0).split()
            self.attrs['elapsed'] = float(parts[0])
            self.attrs['time'] = dt.datetime(int(parts[1]),  # year
                                             int(parts[2]),  # month
                                             int(parts[3]),  # day
                                             int(parts[4]),  # hour
                                             int(parts[5]),  # min
                                             int(parts[6]))  # sec
        # Save header info that is useful.
        raw.pop(0)
        self.attrs['namevar'] = raw.pop(0).split()
        self.attrs['npoints'] = len(raw)

        # Parse remaining data into a dictionary:
        units = {'l': 'hours', 'R': 'cm-3', 'p': 'eV'}
        for name in self.attrs['namevar']:
            self[name] = dm.dmfilled(self.attrs['npoints'],
                                     attrs={'units': units[name[0]]})

        for i, line in enumerate(raw):
            vals = line.split()
            for j, name in enumerate(self.attrs['namevar']):
                if vals[j] == '*************':
                    vals[j] = 100000.0
                self[name][i] = float(vals[j])

    def write(self):
        '''
        Write self to self.filename.
        '''
        # Open file:
        out = open(self.attrs['file'], 'w')
        # Write header:
        out.write('%10.5E %4i %2i %2i %2i %2i %2i\n' %
                  (self.attrs['elapsed'], self.attrs['time'].year,
                   self.attrs['time'].month, self.attrs['time'].day,
                   self.attrs['time'].hour, self.attrs['time'].minute,
                   self.attrs['time'].second)
                  )
        out.write(' Units are Hours, cm-3, and eV\n')
        out.write(' '+' '.join(self.attrs['namevar'])+'\n')
        # Write data and close.
        for i in range(self.attrs['npoints']):
            out.write('%02i %13.6E %13.6E %13.6E %13.6E %13.6E %13.6E\n' %
                      (self[self.attrs['namevar'][0]][i],
                       self[self.attrs['namevar'][1]][i],
                       self[self.attrs['namevar'][2]][i],
                       self[self.attrs['namevar'][3]][i],
                       self[self.attrs['namevar'][4]][i],
                       self[self.attrs['namevar'][5]][i],
                       self[self.attrs['namevar'][6]][i]))
        out.close()


class BoundaryGroup(PbData):
    '''
    A class that collects many :class:`PlasmaBoundary` objects together to
    work as a coherent group.
    '''
    def __init__(self, path='.', rotate=True, *args, **kwargs):
        from glob import glob
        from matplotlib.dates import date2num

        # Init base object.
        super(BoundaryGroup, self).__init__(*args, **kwargs)

        # Load files and count them!
        files = glob(path+'/bound_plasma*.out')
        nfiles = len(files)
        if nfiles == 0:
            raise ValueError('No files found in path=' + indir)

        # Use info from first file to set up data structures.
        temp = PlasmaBoundary(files[0])
        namevar = temp.attrs['namevar']
        self['time'] = dm.dmfilled(nfiles, dtype=object)

        for name in namevar:
            self[name] = dm.dmfille((25, nfiles), fillval=0,
                                    attrs={'units': temp[name].attrs['units']})

        for i, f in enumerate(files):
            temp = PlasmaBoundary(f)
            for name in namevar:
                self[name][:, i] = temp[name]
            self['time'][i] = (temp.attrs['time'])

        # Create some new values to plot:
        self['nAll'] = dm.dmarray(self['RhoH'] + self[namevar[2]] + self['RhoO'],
                                  attrs={'units': 'cm-3'})
        self['ratO'] = dm.dmarray(100.0*self['RhoO']/self['nAll'],
                                  attrs={'units': '\%'})

        if rotate:
            for val in list(self.keys()):
                if val == 'time':
                    continue
                temparray = self[val].copy()
                temparray[0:12, :] = self[val][13:25, :]
                temparray[12:25, :] = self[val][0:13, :]
                self[val][:, :] = temparray[:, :]

        # Put pressure/temp in keV.
        for val in list(self.keys()):
            if (val[0] == 'p') and (self[val].attrs['units'] == 'eV'):
                self[val] /= 1000.0
                self[val].attrs['units'] = 'keV'

        # Internals for plotting:
        self._y = np.arange(0, 26) - 0.5
        self._lt_labels = ['Dusk', 'Midnight', 'Dawn']
        self._yticks = [6.0, 12.0, 18.0]
        self._dtime = date2num(self['time'])  # create decimal time.
        self._zlims = {'p': [0, 40], 'R': [0, 8], 'r': [0, 60], 'n': [0, 8]}

    def add_ltut(self, var, target=None, loc=111, cmap='inferno', zlim=None,
                 add_cbar=True, clabel=None, xlabel='full', title=None,
                 grid=True, ntick=5):
        '''
        Plot variable *var* as a contour against local time (y-axis) and
        universal time (x-axis) using the PyBats *target* method of other
        standard plotting methods.  Four items are returned: the Matplotlib
        Figure, Axes, Mesh, and ColorBar objects used (if add_cbar is set to
        **False**, the returned ColorBar object is simply set to **False**.)

        ========== =======================================================
        Kwarg      Description
        ========== =======================================================
        target     Select plot destination.  Defaults to new figure/axis.
        loc        The location of any generated subplots.  Default is 111.
        add_cbar   Toggles the automatic colorbar.  Default is**True**.
        cmap       Selects Matplotlib color table.  Defaults to *inferno*.
        zlim       Limits for z-axis.  Defaults to best-guess.
        clabel     Sets colorbar label.  Defaults to *var* units.
        xlabel     Sets x-axis limits, use 'full', 'ticks', or **None**.
        title      Sets axis title; defaults to **None**.
        grid       Show white dotted grid?  Defaults to **True**
        ntick      Number of attempted cbar ticks.  Defaults to 5.
        ========== =======================================================

        '''

        import matplotlib.pyplot as plt
        from matplotlib.ticker import MultipleLocator

        fig, ax = set_target(target, loc=loc)

        # Set up z-limits; use variable-specific defaults.
        if zlim is None:
            try:
                zlim = self._zlims[var[0]]
            except ValueError:
                print("No default zlimits for ", var)
                zlim = None

        # Create plot:
        mesh = ax.pcolormesh(self._dtime, self._y, self[var],
                             cmap=cmap, vmin=zlim[0], vmax=zlim[-1])
        # Use LT ticks and markers on y-axis:
        ax.set_yticks(self._yticks)
        ax.set_yticklabels(self._lt_labels)
        ax.set_ylim([4, 20])

        # White ticks, slightly thicker:
        ax.tick_params(axis='both', which='both', color='w', width=1.2)

        # Grid marks:
        if grid:
            ax.grid(c='w')
        if title:
            ax.set_title(title)
        if xlabel == 'full':
            # Both ticks and label.
            applySmartTimeTicks(ax, self['time'], dolabel=True)
        elif xlabel == 'ticks':
            # Ticks, but no date label.
            applySmartTimeTicks(ax, self['time'], dolabel=False)
        else:
            # A blank x-axis is often useful.
            applySmartTimeTicks(ax, self['time'], dolabel=False)
            ax.set_xticklabels('')
        # Add cbar as necessary:
        if add_cbar:
            lct = MultipleLocator(np.ceil(10*(zlim[1]-zlim[0])/(ntick-1))/10.0)
            cbar = plt.colorbar(mesh, ax=ax, pad=0.01, shrink=0.85, ticks=lct)
            cbar.set_label(clabel)
        else:
            cbar = None

        return fig, ax, mesh, cbar


class PressureFile(PbData):
    '''
    A class for reading and visualizing pressure_####.in files.
    '''

    def __init__(self, filename, *args, **kwargs):
        from dateutil.parser import parse

        # Init base object.
        super(PressureFile, self).__init__(*args, **kwargs)

        # Set up object.
        self.attrs['file'] = filename

        # Read and parse file.
        with open(filename, 'r') as fh:
            lines = fh.readlines()
        head_entries = lines[1].strip().split()
        variables = head_entries[:-1]
        p_unit = head_entries[-1].replace('[', '').replace(']', '')

        def name_map(namein):
            '''convert RAM pressure file pressure variable names to SpacePy names

            This module uses pressure variable names "per[species]" for perpendicular
            pressure and "par[species]" for parallel pressure.
            The species names use the case (e.g., helium is He) and electrons are
            always given as a lower case "e". In the RAM pressure files the variables
            are "PPAR_[species]" where the species use title case.

            Examples
            --------
            >>> name_map('PPAR_E')
            'pare'
            >>> name_map('PPER_He')
            'perHe'
            >>> name_map('PTotal')
            'total'
            '''
            # generic as RAM can now use specified list of named species
            parts = namein.split('_')
            n_parts = len(parts)
            # Is a species name present?
            spec = parts[1] if n_parts == 2 else ''
            # Is it a pressure? Drop leading P
            if namein.lower().startswith('p'):
                varname = parts[0][1:].lower()
            else:
                varname = parts[0].lower()
            # Is it electrons? Make sure the name is lower case
            if spec and spec.lower() == 'e':
                spec = 'e'
            return ''.join([varname, spec])

        # Create variables:
        nRec = len(lines[2:])
        varlist = []
        varidx = []
        for idx, vname in enumerate(variables):
            if vname.lower() == 'lsh':
                varlist.append('L')
                varidx.append(idx)
                self['L'] = dm.dmfilled(nRec, attrs={'units': 'RE'})
            elif vname.lower() == 'mlt':
                varlist.append('mlt')
                varidx.append(idx)
                self['mlt'] = dm.dmfilled(nRec, attrs={'units': 'Hours'})
            else:
                ent_name = name_map(vname)
                varlist.append(ent_name)
                varidx.append(idx)
                self[ent_name] = dm.dmfilled(nRec, attrs={'units': p_unit})

        try:
            self.attrs['time'] = parse(lines[0][5:28], fuzzy=True)
        except:
            self.attrs['time'] = 'unknown'

        # Loop over all variables and grab value from correct column
        for i, line in enumerate(lines[2:]):  # Skip header.
            parts = line.split()
            for lidx, vnam in zip(varidx, varlist):
                self[vnam][i] = parts[lidx]

        # Theta is an angle used for polar plots.
        self['theta'] = self['mlt']*np.pi/12.0 - np.pi/2.0
        self['theta'].attrs = {'units': 'rad'}

        # Grid spacing/size:
        self.attrs['dTheta'] = self['theta'][1]-self['theta'][0]
        self.attrs['nTheta'] = int(np.round(2.*np.pi/self.attrs['dTheta'])+1)
        self.attrs['nL'] = len(self['L'])//self.attrs['nTheta']
        self.attrs['dL'] = self['L'][self.attrs['nTheta']] - self['L'][0]

        # Calculate isotropic pressures and anisotropies.
        # Calculate totals, set labels and metadata
        self.labels = {}
        parallels = [key for key in self if key.startswith('par')]
        for var in parallels:
            spec = var[3:]  # species is everything after the "par"a
            if spec == 'e':
                texspec = 'e$^{-}$'
            else:
                texspec = spec + '$^{+}$'  # for now assume all singly ionized
            self['tot' + spec] = (2./3.)*self['per'+spec] + (1./3.)*self['par'+spec]
            self['ani' + spec] = self['per' + spec]/self['par' + spec] - 1.0
            self['tot' + spec].attrs = {'units': ''}  # Isotropy units
            self['per' + spec].attrs['label'] = r'$\bot$ Pressure, ' + texspec
            self['par' + spec].attrs['label'] = r'$\parallel$ Pressure, ' + texspec
            self['tot' + spec].attrs['label'] = r'Pressure, ' + texspec
            self['ani' + spec].attrs['label'] = r'Anisotropy, ' + texspec

        self['total'].attrs['label'] = r'Total Pressure'

    def add_cont_press(self, var='total', n=31, target=None, maxz=1000.0,
                       minz=1.0, loc=111, add_cbar=False, npa=False,
                       labelsize=15, title='auto', cmap='inferno', **kwargs):
        '''
        Create a polar log-axis contour plot of pressure and add it to
        *target*.  For speedier plots, use plot_cont_press, which makes its
        own axis.

        Parameters
        ==========

        Returns
        =======
        fig : matplotlib figure object
        ax  : matplotlib axes object
        cont : matplotlib contour object
        cbar : matplotlib colorbar object

        Other Parameters
        ================
        var : string
             The variable within the object to plot.  Defaults to 'total'.
             Can be set to other species-specific pressure values.
        n : integer
             The number of contours.  Defaults to 31.
        maxz : real
             The color bar maximum.  Defaults to 1000.0
        minz : real
             The color bar minimum.  Defaults to 1.0.
        add_cbar : bool
             Set whether to add a color bar or not.  Defaults to **False**.
        cmap : string
             Set name of contour color map to use.  Defaults to 'inferno'.
        npa : bool
             If **True**, plot in units of nanopascal instead of energy density.
             Defaults to **False**.
        labelsize : int
             Sets the font size of the labels.  Defaults to 15.
        title : string
             Sets the plot title.  Defaults to 'auto', using the variable label.
        target : Figure or Axes
             If None (default), a new figure is generated from scratch.
             If a matplotlib Figure object, a new axis is created
             to fill that figure.
             If a matplotlib Axes object, the plot is placed
             into that axis.
        loc : int
            Use to specify the subplot placement of the axis
            (e.g. loc=212, etc.) Used if target is a Figure or None.
            Default 111 (single plot).

        '''
        from matplotlib.colors import LogNorm
        from matplotlib.pyplot import colorbar
        from matplotlib.ticker import LogLocator, LogFormatterMathtext

        fig, ax = set_target(target, loc=loc, polar=True)

        p = self[var]
        label = '$KeV/cm^-3$'
        if title == 'auto':
            title = self[var].attrs['label']
        if npa:
            p = p*0.16  # Energy Density to Pressure in nPa.
            label = 'nPa'
        # Set up color bar & levels.
        levs = np.power(10, np.linspace(np.log10(minz), np.log10(maxz), n))
        minz = 0.01
        cont = ax.tricontourf(self['theta'], self['L'], np.asarray(p), levs,
                              norm=LogNorm(), cmap=cmap)
        _adjust_dialplot(ax, self['L'], title=title, labelsize=labelsize)
        if add_cbar:
            cbar = colorbar(cont, pad=0.1, ticks=LogLocator(), ax=ax,
                            format=LogFormatterMathtext(), shrink=0.8)
            # cbar.set_label(self.labels[var]+' ($KeV/cm^-3)$')
            cbar.set_label(label)
        else:
            cbar = None

        return fig, ax, cont, cbar

    def add_pcol_press(self, var='total', target=None, maxz=1000.0, minz=1.0,
                       add_cbar=False, loc=111, labelsize=15, title='auto'):
        '''
        Add a pcolor plot of the pressure object to *target*.

        Parameters
        ==========

        Returns
        =======
        fig : matplotlib figure object
        ax  : matplotlib axes object
        cont : matplotlib contour object
        cbar : matplotlib colorbar object

        Other Parameters
        ================
        var : string
             The variable within the object to plot.  Defaults to 'total'.
             Can be set to other species-specific pressure values.
        maxz : real
             The color bar maximum.  Defaults to 1000.0
        minz : real
             The color bar minimum.  Defaults to 1.0.
        add_cbar : bool
             Set whether to add a color bar or not.  Defaults to **False**.
        labelsize : int
             Sets the font size of the labels.  Defaults to 15.
        title : string
             Sets the plot title.  Defaults to 'auto', using the variable label.
        target : Figure or Axes
             If None (default), a new figure is generated from scratch.
             If a matplotlib Figure object, a new axis is created
             to fill that figure.
             If a matplotlib Axes object, the plot is placed
             into that axis.
        loc : int
            Use to specify the subplot placement of the axis
            (e.g. loc=212, etc.) Used if target is a Figure or None.
            Default 111 (single plot).

        '''
        from matplotlib.colors import LogNorm
        from matplotlib.cm import get_cmap
        from matplotlib.pyplot import colorbar
        from matplotlib.ticker import LogLocator, LogFormatterMathtext

        fig, ax = set_target(target, loc=loc, polar=True)

        # Set title.
        if title == 'auto':
            title = self[var].attrs['label']

        # Set up grid centered on gridpoints.
        dT = self.attrs['dTheta']
        dL = self.attrs['dL']
        T = np.linspace(-1.0*dT/2.0, 2.*np.pi-dT/2.0, self.attrs['nTheta'])
        T = T-np.pi/2.0
        R = np.linspace(self['L'][0]-dL/2.0, self['L'][-1]+dL/2.0, self.attrs['nL']+1)
        p = np.reshape(self[var], [self.attrs['nL'], self.attrs['nTheta']])
        ax.grid(False)  # as of mpl 3.5 grid must be turned off before calling pcolormesh
        pcol = ax.pcolormesh(T, R, p[:, :-1], norm=LogNorm(vmin=minz, vmax=maxz),
                             cmap=get_cmap('inferno'))
        _adjust_dialplot(ax, R, title=title, labelsize=15)
        if add_cbar:
            cbar = colorbar(pcol, pad=0.1, ticks=LogLocator(), ax=ax,
                            format=LogFormatterMathtext(), shrink=0.8)
            # cbar.set_label(self.labels[var] + ' ($keV/cm^{-3}$)')
            cbar.set_label('$keV/cm^{-3}$')
        else:
            cbar = None

        return fig, ax, pcol, cbar


class BoundaryFluxFile(object):
    '''
    Read, plot, and edit flux (*.swf) or (*.dat) files.
    *.dat files are output into the Dsbnd directory.
    '''
    def __init__(self, filename):
        self.filename = filename
        if filename[-3:] == 'swf':
            self.read_swf()
        else:
            self.read_dsbnd()

    def read_dsbnd(self):
        from datetime import datetime
        from re import search
        from numpy import zeros, linspace
        f = open(self.filename, 'r')
        lines = f.readlines()
        f.close()

        parts = lines[0].split()
        self.rtime = float(parts[-1])

        # Try to get run time, species from filename.
        match = search('ds(\w{2})\_d(\d{4})(\d{2})(\d{2})\_t(\d{2})(\d{2})(\d{2})',
                       self.filename)
        if match:
            # New filename format! Huzzah!
            t = match.groups()
            self.species = t[0].strip('_')
            self.time = datetime(int(t[1]), int(t[2]), int(t[3]),
                                 int(t[4]), int(t[5]), int(t[6]))
        else:
            self.time = None
            self.species = None

        # Determine size of file and allocate array.
        self.nE = len(lines) - 1
        parts = lines[1].split()
        self.nLT = len(parts)-1
        self.flux = zeros([self.nLT, self.nE])
        self.E = zeros(self.nE)

        # Read and parse lines.
        for i, line in enumerate(lines[1:]):
            parts = line.split()
            self.E[i] = float(parts[0])
            for j in range(self.nLT):
                self.flux[j, i] = float(parts[j+1])

        # Set up local time grid.
        self.LT = linspace(0, 24, self.nLT)

    def read_swf(self):
        f = open(self.filename, 'r')
        lines = f.readlines()
        f.close()

        # Determine size of file and allocate array.
        self.nLT = len(lines) - 2
        parts = lines[1].split()
        self.nE = len(parts)-2
        self.flux = np.zeros([self.nLT, self.nE])

        # Read and parse lines.
        for i, line in enumerate(lines[1:-1]):
            parts = line.split()
            for j in range(self.nE):
                self.flux[i, j] = float(parts[j+2])

        # Set up local time grid.
        self.LT = np.linspace(0, 24, self.nLT)

    def quickplot(self, zlim=[10, 1e7]):
        '''
        A quick plot of input flux on a fresh axis.
        '''
        import matplotlib.pyplot as plt
        from matplotlib.colors import LogNorm
        from matplotlib.ticker import LogLocator, LogFormatterMathtext
        fig = plt.figure()
        ax = fig.add_subplot(111)

        egrid = np.array(range(self.nE))
        flux = self.flux.transpose()
        flux[flux < 0.01] = 0.01
        flx = ax.pcolor(self.LT, egrid, flux,
                        norm=LogNorm(vmin=zlim[0], vmax=zlim[-1]),
                        cmap=plt.get_cmap('inferno'))
        cbar = plt.colorbar(flx, pad=0.01, shrink=0.85, ticks=LogLocator(),
                            format=LogFormatterMathtext())
        cbar.set_label('$cm^{-2}s^{-1}ster^{-1}keV^{-1}$')
        ax.set_xlim([0, 24])
        ax.set_ylim([0, self.nE-1])
        if hasattr(self, 'time'):
            ax.set_title(self.time.isoformat())
        ax.set_xlabel('Local Time Sector')
        if hasattr(self, 'E'):
            ax.set_ylabel('Energy (keV)')
            newlabs = []
            for val in ax.get_yticks()[:-1]:
                newlabs.append('%6.2f' % self.E[int(val)])
            ax.set_yticklabels(newlabs)
        else:
            ecentr, ebound, ewidth = gen_egrid(self.nE)
            ax.set_ylabel('Energy (keV)')
            newlabs = []
            for val in ax.get_yticks()[:-1]:
                newlabs.append('%6.2f' % ecentr[int(val)])
            ax.set_yticklabels(newlabs)

        return fig, ax


class LogFile(PbData):
    def __init__(self, file, *args, **kwargs):
        super(LogFile, self).__init__(*args, **kwargs)
        self.attrs['file'] = file
        self.read()

    def read(self):
        '''
        Load the ascii logfile located at self.filename.
        This method is automatically called upon instantiation.
        '''
        # Slurp in entire file.
        infile = open(self.attrs['file'], 'r')
        raw = infile.readlines()
        infile.close()

        # Parse the header.
        self.attrs['descrip'] = raw.pop(0)
        namevar = (raw.pop(0)).split()
        nCols = len(namevar)
        loc = {}
        for i, name in enumerate(namevar):
            loc[name] = i

        # Check the last line for completeness.
        # Files read while simulation is running will have incomplete
        # lines.
        nPts = len(raw)
        checkline = raw[-1].split()
        if len(checkline) != nCols:
            nPts -= 1
        self.attrs['npts'] = nPts

        # Pop time/date names off of Namevar.
        for nvr in ['year', 'mo', 'dy', 'hr', 'mn', 'sc', 'msc', 'time']:
            namevar.pop(namevar.index(nvr))

        # Create containers for data:
        self['runtime'] = dm.dmfilled(nPts, attrs={'units': 's'})
        self['time'] = dm.dmfilled(nPts, dtype=object)
        self['iter'] = dm.dmfilled(nPts)
        for name in namevar:
            self[name] = dm.dmfilled(nPts)

        for i, line in enumerate(raw[:nPts]):
            vals = line.split()
            # Set time:
            self['time'][i] = (dt.datetime(int(vals[loc['year']]),  # Year
                                           int(vals[loc['mo']]),  # Month
                                           int(vals[loc['dy']]),  # Day
                                           int(vals[loc['hr']]),  # Hour
                                           int(vals[loc['mn']]),  # Minute
                                           int(vals[loc['sc']]),  # Second
                                           int(vals[loc['msc']])*1000  # microsec
                                           )
                               )
            self['runtime'][i] = float(vals[loc['time']])
            # Collect data
            for j, name in enumerate(namevar):
                self[name][i] = float(vals[loc[name]])

    def add_dst_quicklook(self, target=None, loc=111, showObs=True,
                          showBiot=True):
        '''
        Create a quick-look plot of Dst.  If kyotodst module is
        installed, compare to observed Dst.

        Two values are returned: the matplotlib Figure and Axes objects
        used to generate the plot (in that order.)

        Parameters
        ==========

        Returns
        =======
        fig : matplotlib figure object
        ax  : matplotlib axes object

        Other Parameters
        ================
        target : Figure or Axes
             If None (default), a new figure is generated from scratch.
             If a matplotlib Figure object, a new axis is created
             to fill that figure.
             If a matplotlib Axes object, the plot is placed
             into that axis.
        loc : int
            Use to specify the subplot placement of the axis
            (e.g. loc=212, etc.) Used if target is a Figure or None.
            Default 111 (single plot).
        showObs : bool
            Show observed Dst?  Defaults to **True**
        showBiot : bool
            Show Biot-Savart Dst?  Defaults to **True**


        '''
        fig, ax = set_target(target, loc=loc)

        ax.plot(self['time'], self['dstRam'], label='RAM Dst (DPS)')
        if 'dstBiot' in self and showBiot:
            ax.plot(self['time'], self['dstBiot'], label='RAM Dst (Biot)')
        ax.hlines(0.0, self['time'][0], self['time'][-1],
                  'k', ':', label='_nolegend_')

        try:
            import spacepy.pybats.kyoto as kt
        except ImportError:
            return fig, ax

        if showObs:
            try:
                stime = self['time'][0]
                etime = self['time'][-1]
                if not hasattr(self, 'obs_dst'):
                    self.obs_dst = kt.fetch('dst', stime, etime)
            except BaseException as args:
                print('WARNING! Failed to fetch Kyoto Dst: ', args)
            else:
                ax.plot(self.obs_dst['time'], self.obs_dst['dst'],
                        'k--', label='Obs. Dst')
                ax.legend(loc='best')
        else:
            ax.legend(loc='best')
        applySmartTimeTicks(ax, self['time'], dolabel=True)
        ax.set_ylabel('Dst [$nT$]')

        return fig, ax


class IonoPotScb(PbData):
    '''
    The 3D equilibrium code produces NetCDF files that contain the
    ionospheric potential on the polar cap as well as mapped to the
    equatorial plane.  The IonoPotScb object can be used to parse and
    visualize the data quickly.
    '''
    def __init__(self, filename, *args, **kwargs):
        super(IonoPotScb, self).__init__(*args, **kwargs)
        self.filename = filename
        self._read()

    def _read(self):
        '''
        Load the NetCDF file. Should only be called by __init__
        '''
        # Load file with scipy.io.netcdf
        with scipy.io.netcdf_file(self.filename,
                                  mode='r', mmap=False) as nfh:
            # split off the netCDF attributes from the Python attributes
            for k in dir(nfh):
                if k[0] == '_' or k in ('dimensions', 'filename', 'fp', 'mode',
                                        'use_mmap', 'variables', 'version_byte'):
                    continue
                tmp = getattr(nfh, k)
                if not callable(tmp):
                    self.attrs[k] = tmp

            self.NameVars = list(nfh.variables.keys())
            # self.filedata contains the raw netcdf objects.
            for var in nfh.variables:
                self[var] = dm.dmarray(nfh.variables[var][...])
            self.filedata = nfh.variables
            self.time = nfh.variables['time'][...]

        # Determine units of potential.
        if self['PhiIono'].max()/1000.0 > 10.0:
            self.units = 'V'
        else:
            self.units = 'kV'

    def calc_pot_drop(self):
        '''
        Calculate the electric potential drop across the inner magnetosphere
        for the whole time period.  This value is analogous to cross polar
        cap potential drop, but is only valid inside of the RAM-SCB domain.

        This value is simply the maximum potential minus the minimum potential.
        The new data entry is stored using key 'ceqp', which stands for the
        cross equatorial potential.
        '''
        self['ceqp'] = dm.dmfilled(len(self.time), fillval=0)

        for i in range(len(self.time)):
            self['ceqp'][i] = self['PhiIono'][i, :, :].max() - \
                              self['PhiIono'][i, :, :].min()
        if self.units == 'V':
            self['ceqp'] = self['ceqp']/1000.0

    def plot_eqPot(self, time, target=None, range=200, n=31, add_cbar=True):
        '''
        Plot the equatorial electric potential in kV to target, where
        target may be a matplotlib figure or axis or None.  If target
        is a figure, a new subplot is created.  If target is None, a
        new figure AND axis is created.
        Parameters
        ==========
        time : int
            An array index indicating what epoch to plot.

        Returns
        =======
        fig : matplotlib figure object
        ax  : matplotlib axes object
        cont : matplotlib contour object
        cbar : matplotlib colorbar object

        Other Parameters
        ================
        n : integer
             The number of contours.  Defaults to 31.
        range : real
             The max and min of the contour range.
        add_cbar : bool
             Set whether to add a color bar or not.  Defaults to **False**.
        target : Figure or Axes
             If None (default), a new figure is generated from scratch.
             If a matplotlib Figure object, a new axis is created
             to fill that figure.
             If a matplotlib Axes object, the plot is placed
             into that axis.
        loc : int
            Use to specify the subplot placement of the axis
            (e.g. loc=212, etc.) Used if target is a Figure or None.
            Default 111 (single plot).

        '''

        import matplotlib.pyplot as plt
        from matplotlib.colors import Normalize
        from matplotlib.ticker import MultipleLocator

        fig, ax = set_target(target, loc=111)

        cmap = get_iono_cb('bwr')
        crange = Normalize(vmin=-1.*range, vmax=range)
        levs = np.linspace(-1*range, range, n)

        factor = 1.0
        if self.units == 'V':
            factor = 1000.0

        ax.set_aspect('equal')
        ax.set_xlabel('Y (R$_{E}$)')
        ax.set_ylabel('X (R$_{E}$)')
        cont = ax.contourf(self['yEq'][time, :, :], self['xEq'][time, :, :],
                           np.asarray(self['PhiIono'][time, :, :])/factor,
                           levs, norm=crange, cmap=cmap)
        add_body(ax, rotate=90.0)
        cbar = False
        if add_cbar:
            cticks = MultipleLocator(50)
            cbar = plt.colorbar(cont, ticks=cticks, shrink=0.8, pad=0.08)
            cbar.set_label('kV')
        return fig, ax, cont, cbar


class Currents(object):
    '''
    The 3D equilibrium code produces NetCDF files that contain the
    electric currents throughout the domain.  Currents objects parse
    and visualize this data.

    For quick parsing of these files, PyNIO is required.
    '''

    def __getitem__(self, key):
        if key in self.filedata:
            return self.filedata[key].get_value()
        elif key in self.data:
            return self.data[key]
        else:
            raise KeyError('Key not found in object.')

    def __setitem__(self, key, value):
        self.data[key] = value

    def keys(self):
        '''
        List all keys for data objects stored in the IonoPotScb object.
        '''
        return list(self.filedata.keys()) + list(self.data.keys())

    def __init__(self, filename):
        try:
            from PyNIO import Nio
        except ImportError:
            try:
                import Nio
            except ImportError:
                raise ImportError('PyNIO required, not found.')

        self.filename = filename

        # Load file as Nio object.
        f = Nio.open_file(filename, 'r')
        self.NameVars = list(f.variables.keys())
        self.attrs = f.attributes
        # self.filedata contains the raw NioVariable objects.
        self.filedata = f.variables
        self.time = f.variables['time'].get_value()
        # New values saved as self[key] are stored in self.data, not
        # self.filedata which cannot be changed.
        self.data = {}

        self._netcdf = f

    def close(self):
        '''
        Close the NetCDF file.  This will make values stored inside of the
        file unavailable to the user.
        '''
        self._netcdf.close()

    def plot_jpar(self, ax, time, maxz=0.5):
        from spacepy.pybats.rim import get_iono_cb
        from matplotlib.colors import Normalize
        cmap = get_iono_cb('bwr')
        crange = Normalize(vmin=-1.*maxz, vmax=maxz)
        cnt1 = ax.contourf(self['xPole'][time, :, :], self['yPole'][time, :, :],
                           self['jParVas'][time, :, :], norm=crange, cmap=cmap)


class ParamFile(object):
    '''
    It is sometimes necessary to read and parse a PARAM.in file.  ParamFile
    objects quickly parse the info and store it in a convenient data structure.
    '''

    def __repr__(self):
        return 'PARAM file at %s with %i commands.' % \
            (self.path+self.file, len(self.cmd))

    # Make 'er work like a dict.
    def __getitem__(self, key):
        return self.cmd[key]

    def keys(self):
        return list(self.cmd.keys())

    def __contains__(self, key):
        return key in self.cmd

    def __init__(self, infile):
        '''
        Read the file, parse each command.
        '''
        # Grab the full path and save it.
        if infile.rfind('/') > -1:
            self.path = infile[0:infile.rfind('/')+1]+'/'
        else:
            self.path = './'
        self.file = infile
        # Slurp entire file.
        f = open(infile, 'r')
        lines = f.readlines()
        f.close()

        # Some commands have specialized parse functions.
        # Those are connected here.
        self.known_cmds = {'STARTTIME': self._parse_starttime,
                           'STOP': self._parse_stop}
        self.cmd = {}
        self._parse(lines)

    # Command specific parsers:
    def _add_cmd(self, cmd_name, lines):
        self.cmd[cmd_name] = []
        npop = 0
        for line in lines:
            if line.strip() == '' or line[0] == '#':
                break
            self.cmd[cmd_name].append(line.strip())
            npop += 1
        return npop

    def _parse_stop(self, lines):
        self.iters = int(lines[0].split()[0])
        self.dur = float(lines[1].split()[0])
        self.stoptime = self.starttime+dt.timedelta(seconds=self.dur)
        return 2

    def _parse_starttime(self, lines):
        self.starttime = dt.datetime(
            int(lines[0].split()[0]),  # year
            int(lines[1].split()[0]),  # month
            int(lines[2].split()[0]),  # day
            int(lines[3].split()[0]),  # hour
            int(lines[4].split()[0]),  # minute
            int(lines[5].split()[0]),  # second
            int(float(lines[6].split()[0])*1E6))  # millisec
        return 7

    # Quick function to pop multiple lines.
    def _parse(self, lines):
        # A quick function for multi-popping.
        def pop(arr, n):
            for i in range(n):
                arr.pop(0)
            return arr
        # Loop throug all lines!
        while len(lines) > 0:
            line = lines.pop(0)
            if line[0] != '#':
                continue  # Find first/next #COMMAND statement.
            line = line.strip()

            # Skip begin/end comps.
            if line.find('BEGIN_COMP') > -1 or line.find('END_COMP') > -1:
                continue

            if line[1:] in self.known_cmds:
                # If recognized command, process and pop arguments.
                npop = self.known_cmds[line[1:]](lines)
                pop(lines, npop)
            else:
                npop = self._add_cmd(line[1:], lines)
                pop(lines, npop)


class GeoMltFile(object):
    '''
    GeoMltFile is a class to open, read, manipulate and write files that
    contain LANL geosynchronous multi-satellite averaged, MLT-interpolated
    fluxes.
    '''
    def __init__(self, filename=None, scrub=True,
                 compressed=False):
        # Create empty arrays.
        self.flux = np.zeros([288, 24, 36])
        self.time = np.zeros(288, dtype=object)
        self.egrid = np.zeros(36)
        self.nsats = np.zeros((288, 24, 36), dtype=int)
        self.header = []
        self.particle = 'proton'

        if filename:
            self.filename = filename
            self.read(compressed=compressed)

    def read(self, compressed=False):
        '''
        Load contents from *self.filename*.
        '''
        import gzip
        # Open file
        myopen = open if not compressed else gzip.open
        with myopen(self.filename, 'r') as fh:
            def read_compressed(filehandle=fh):
                return filehandle.readline().decode()
            read_one_line = fh.readline if not compressed else read_compressed
            # #Parse header information#
            # Read header
            for i in range(3):
                line = read_one_line()
                self.header.append(line)
            # Set measurement type:

            if (self.header[0]).find('electron') > 0:
                self.particle = 'electron'
            # Parse energy grid.
            parts = read_one_line().split()
            # pop three times
            parts.pop(0)
            parts.pop(0)
            parts.pop(0)
            self.egrid[:] = parts[-36:]

            # ## Parse fluxes. ##
            # Slurp rest of file and close.
            lines = fh.readlines()

        # Grab L-grid.
        lt = []
        lt.append(float(lines[0].split()[1]))
        lt.append(float(lines[1].split()[1]))
        i = 2
        while lt[0] != lt[-1]:
            lt.append(float(lines[i].split()[1]))
            i += 1
        self.lgrid = np.array(lt[:-1])
        nL = self.lgrid.size
        # Parse file one epoch at a time.
        for i in range(288):
            # Get one epoch worth of data.
            sublines = lines[nL*i:nL*i+nL]
            # Get time for this epoch.
            t = sublines[0].split()[0]
            self.time[i] = dt.datetime(int(t[0:4]), int(t[5:7]),
                                       int(t[8:10]), int(t[11:13]),
                                       int(t[14:16]), int(t[17:19]),
                                       1000*int(t[20:23]))
            # Parse rest of lines.
            for j, l in enumerate(sublines):
                # Use some string comprehension magic.
                self.nsats[i, j, :] = [l[32+2*x:32+2*x+2] for x in range(36)]
                self.flux[i, j, :] = [l[104+18*x:104+18*x+18] for x in range(36)]

    def scrub(self, lastflux=None):
        '''
        GeoMlt files often have bad data througout in the form of negative
        or zero fluxes.  In RAM-SCB, these are replaced with the last good
        data value.  This function "scrubs" the data in the same manner as
        RAM-SCB.  The kwarg *lastflux* may be given as a nLT x nE numpy array
        of the last good fluxes, e.g. the correct values at the epoch directly
        preceeding the first epoch of this file.  These will be used if the
        first time entry of the file contains bad values.  If not given, bad
        values at the first time entry will be set to zero.
        '''
        # Handle first line:
        if lastflux:
            # Check lastflux.
            if lastflux.shape != (self.lgrid.size, self.egrid.size):
                raise ValueError("Shape of lastflux is incorrect.")
            self.flux[0, self.flux[0, :, :] <= 0.0] = lastflux[self.flux[0, :, :] <= 0.0]
        else:
            self.flux[0, self.flux[0, :, :] <= 0.0] = 0.0

        for i in range(1, 288):
            self.flux[i, self.flux[i, :, :] <= 0.0] = \
                self.flux[i-1, self.flux[i, :, :] <= 0.0]

    def __iadd__(self, other):
        '''
        Append another **GeoMltFile** object to this one using +=
        '''
        if type(self) != type(other):
            raise TypeError(
                'object can only be combined with one of same type.')

        # Grid checks:
        if any(self.egrid != other.egrid):
            raise ValueError('both items must have identical energy grids!')
        if any(self.lgrid != other.lgrid):
            raise ValueError('both items must have identical MLT grids!')
        if self.particle != other.particle:
            raise ValueError('both items must have identical particles!')

        # Append data together:
        self.time = np.append(self.time, other.time)
        self.flux = np.append(self.flux, other.flux, 0)
        self.nsats = np.append(self.nsats, other.nsats, 0)

        # Append file names:
        if type(self.filename) == str:
            self.filename = [self.filename]
        self.filename.append(other.filename)

        return self

    __add__ = __iadd__  # allow add syntax as well as in-place add

    def timeseries_append(self, other):
        '''
        If *other* is of the same type as self, and both have a 'time'
        entry, append all arrays within *other* that have the same size as
        'time' to the corresponding arrays within self.  This is useful
        for combining time series data of consecutive data.
        '''
        return self.__add__(other)

    def plot_epoch_flux(self, epoch=0, target=None, loc=111,
                        title=None):
        '''
        Plot fluxes (j(E, MLT)) for a single time

        Parameters
        ----------
        epoch : integer or datetime or spacepy.time.Ticktock
            If integer, the index corresponding to the time to be plotted.
            If a supported time type (datetime or Ticktock), the nearest
            index will be looked up and selected.
        target : object
            Target for plotting. If kwarg *target* is **None** (default),
            a new figure is generated. If *target* is a matplotlib Figure
            object, a new axis is created to fill that figure at subplot
            location *loc* (defaults to 111). If target is a matplotlib
            Axes object, the plot is placed into that axis at subplot
            location *loc*.
        loc : integer
            Designator for axis location. See description of target.
        title: str or None
            If not None, specifies the axis title.

        Returns
        -------
        fig : object
          A matplotlib figure object on which to plot.

        ax : object
          A matplotlib subplot object on which to plot.

        '''
        import matplotlib.pyplot as plt
        from matplotlib.colors import LogNorm
        from matplotlib.ticker import LogLocator, LogFormatterMathtext

        if isinstance(epoch, int):
            ep_idx = epoch
        else:
            ep_idx = self.get_index_from_time(epoch)

        fig, ax = set_target(target, loc=loc)

        egrid = np.array(range(len(self.egrid)+1))
        lgrid = np.array(range(len(self.lgrid)+1))
        flux = self.flux[ep_idx, :, :].transpose()
        flux[flux < 0.01] = 0.01
        flx = ax.pcolormesh(lgrid, egrid, flux,
                            norm=LogNorm(vmin=0.01, vmax=1e10),
                            cmap=plt.get_cmap('inferno'))
        cbar = plt.colorbar(flx, pad=0.01, shrink=0.85, ticks=LogLocator(),
                            format=LogFormatterMathtext())
        cbar.set_label('$cm^{-2}s^{-1}ster^{-1}keV^{-1}$')
        ax.set_xlim([0, 24])
        ax.set_ylim([0, len(egrid)])

        default_title = 'Flux at Boundary - {}\n{}'.format(self.filename,
                                                           self.time[ep_idx])
        use_title = default_title if title is None else title
        ax.set_title(use_title)
        ax.set_xlabel('Local Time (hr)')
        # Use actual energy channels.
        ax.set_ylabel('Energy (keV)')
        newlabs = []
        for val in ax.get_yticks()[:-1]:
            newlabs.append('%6.2f' % self.egrid[int(val)])
        ax.set_yticklabels(newlabs)

        return fig, ax

    def get_index_from_time(self, epoch):
        '''
        Given a UTC time (datetime or Ticktock), return nearest index

        Parameters
        ----------
        epoch : datetime.datetime or spacepy.time.Ticktock
            Time as a supported type (UTC as datetime.datetime or
            spacepy.time.Ticktock). The nearest index to this time
            will be looked up and returned.

        Returns
        -------
        idx : integer
        '''
        import bisect
        if isinstance(epoch, spt.Ticktock):
            utc = epoch.UTC[0]
        elif isinstance(epoch, dt.datetime):
            utc = epoch
        else:
            raise TypeError('Unsupported type in get_index_from_time: ' +
                            'Supported types are [datetime.datetime, ' +
                            'spacepy.time.Ticktock, int]')
        cidx = bisect.bisect_left(self.time, utc)
        if cidx == 0:
            idx = 0
        elif cidx == len(self.time):
            idx = len(self.time)-1
        else:
            deltaleft = np.abs((utc - self.time[cidx-1]).total_seconds())
            deltaright = np.abs((utc - self.time[cidx]).total_seconds())
            print(cidx, deltaleft, deltaright)
            idx = cidx-1 if deltaleft <= deltaright else cidx

        return idx
