@@ -40,6 +40,11 @@ markers = {'s': {'marker': 'square'},
 # and can therefore be safely ignored.
 IGNORED_MODELS = ['LinearAxis']
 
+# Model priority order to ensure some types are updated before others
+MODEL_PRIORITY = ['Range1d', 'Title', 'Image', 'LinearColorMapper',
+                  'Plot', 'Range1d', 'LinearAxis', 'ColumnDataSource']
+
+
 def rgb2hex(rgb):
     """
     Convert RGB(A) tuple to hex.
from distutils.version import LooseVersion

from collections import defaultdict
import numpy as np

try:
    from matplotlib import colors
    import matplotlib.cm as cm
except ImportError:
    cm, colors = None, None

import bokeh
bokeh_version = LooseVersion(bokeh.__version__)
from bokeh.core.enums import Palette
from bokeh.document import Document
from bokeh.models.plots import Plot
from bokeh.models import GlyphRenderer
from bokeh.models.widgets import DataTable, Tabs
from bokeh.plotting import Figure

if bokeh_version >= '0.12':
    from bokeh.layouts import WidgetBox

from ...core.options import abbreviated_exception

# Conversion between matplotlib and bokeh markers
markers = {'s': {'marker': 'square'},
           'd': {'marker': 'diamond'},
           '^': {'marker': 'triangle', 'orientation': 0},
           '>': {'marker': 'triangle', 'orientation': np.pi/2},
           'v': {'marker': 'triangle', 'orientation': np.pi},
           '<': {'marker': 'triangle', 'orientation': -np.pi/2},
           '1': {'marker': 'triangle', 'orientation': 0},
           '2': {'marker': 'triangle', 'orientation': np.pi/2},
           '3': {'marker': 'triangle', 'orientation': np.pi},
           '4': {'marker': 'triangle', 'orientation': -np.pi/2}}

# List of models that do not update correctly and must be ignored
# Should only include models that have no direct effect on the display
# and can therefore be safely ignored.
IGNORED_MODELS = ['LinearAxis']

def rgb2hex(rgb):
    """
    Convert RGB(A) tuple to hex.
    """
    if len(rgb) > 3:
        rgb = rgb[:-1]
    return "#{0:02x}{1:02x}{2:02x}".format(*(int(v*255) for v in rgb))


def mplcmap_to_palette(cmap):
    """
    Converts a matplotlib colormap to palette of RGB hex strings."
    """
    if colors is None:
        raise ValueError("Using cmaps on objects requires matplotlib.")
    with abbreviated_exception():
        colormap = cm.get_cmap(cmap) #choose any matplotlib colormap here
        return [rgb2hex(m) for m in colormap(np.arange(colormap.N))]


def get_cmap(cmap):
    """
    Returns matplotlib cmap generated from bokeh palette or
    directly accessed from matplotlib.
    """
    with abbreviated_exception():
        rgb_vals = getattr(Palette, cmap, None)
        if rgb_vals:
            return colors.ListedColormap(rgb_vals, name=cmap)
        return cm.get_cmap(cmap)


def mpl_to_bokeh(properties):
    """
    Utility to process style properties converting any
    matplotlib specific options to their nearest bokeh
    equivalent.
    """
    new_properties = {}
    for k, v in properties.items():
        if k == 's':
            new_properties['size'] = v
        elif k == 'marker':
            new_properties.update(markers.get(v, {'marker': v}))
        elif k == 'color' or k.endswith('_color'):
            with abbreviated_exception():
                v = colors.ColorConverter.colors.get(v, v)
            if isinstance(v, tuple):
                with abbreviated_exception():
                    v = rgb2hex(v)
            new_properties[k] = v
        else:
            new_properties[k] = v
    new_properties.pop('cmap', None)
    return new_properties


def layout_padding(plots):
    """
    Temporary workaround to allow empty plots in a
    row of a bokeh GridPlot type. Should be removed
    when https://github.com/bokeh/bokeh/issues/2891
    is resolved.
    """
    widths, heights = defaultdict(int), defaultdict(int)
    for r, row in enumerate(plots):
        for c, p in enumerate(row):
            if p is not None:
                width = p.plot_width if isinstance(p, Plot) else p.width
                height = p.plot_height if isinstance(p, Plot) else p.height
                widths[c] = max(widths[c], width)
                heights[r] = max(heights[r], height)

    expanded_plots = []
    for r, row in enumerate(plots):
        expanded_plots.append([])
        for c, p in enumerate(row):
            if p is None:
                p = Figure(plot_width=widths[c],
                           plot_height=heights[r])
                p.text(x=0, y=0, text=[' '])
                p.xaxis.visible = False
                p.yaxis.visible = False
                p.outline_line_color = None
                p.xgrid.grid_line_color = None
                p.ygrid.grid_line_color = None
            expanded_plots[r].append(p)
    return expanded_plots


def convert_datetime(time):
    return time.astype('datetime64[s]').astype(float)*1000


def models_to_json(models):
    """
    Convert list of bokeh models into json to update plot(s).
    """
    json_data, ids = [], []
    for plotobj in models:
        if plotobj.ref['id'] in ids:
            continue
        else:
            ids.append(plotobj.ref['id'])
        json = plotobj.to_json(False)
        json.pop('tool_events', None)
        json.pop('renderers', None)
        json_data.append({'id': plotobj.ref['id'],
                          'type': plotobj.ref['type'],
                          'data': json})
    return json_data


def refs(json):
    """
    Finds all the references to other objects in the json
    representation of a bokeh Document.
    """
    result = {}
    for obj in json['roots']['references']:
        result[obj['id']] = obj
    return result


def compute_static_patch(document, models):
    """
    Computes a patch to update an existing document without
    diffing the json first, making it suitable for static updates
    between arbitrary frames. Note that this only supports changed
    attributes and will break if new models have been added since
    the plot was first created.
    """
    references = refs(document.to_json())
    requested_updates = [m.ref['id'] for m in models]

    value_refs = {}
    events = []
    update_types = defaultdict(list)
    for ref_id, obj in references.items():
        if ref_id not in requested_updates and not obj['type'] in IGNORED_MODELS:
            continue
        for key, val in obj['attributes'].items():
            event = Document._event_for_attribute_change(references,
                                                         obj, key, val,
                                                         value_refs)
            events.append(event)
            update_types[obj['type']].append(key)
    value_refs = {ref_id: val for ref_id, val in value_refs.items()
                  if val['type'] not in IGNORED_MODELS}
    return dict(events=events, references=list(value_refs.values()))


def hsv_to_rgb(hsv):
    """
    Vectorized HSV to RGB conversion, adapted from:
    http://stackoverflow.com/questions/24852345/hsv-to-rgb-color-conversion
    """
    h, s, v = (hsv[..., i] for i in range(3))
    shape = h.shape
    i = np.int_(h*6.)
    f = h*6.-i

    q = f
    t = 1.-f
    i = np.ravel(i)
    f = np.ravel(f)
    i%=6

    t = np.ravel(t)
    q = np.ravel(q)
    s = np.ravel(s)
    v = np.ravel(v)

    clist = (1-s*np.vstack([np.zeros_like(f),np.ones_like(f),q,t]))*v

    #0:v 1:p 2:q 3:t
    order = np.array([[0,3,1],[2,0,1],[1,0,3],[1,2,0],[3,1,0],[0,1,2]])
    rgb = clist[order[i], np.arange(np.prod(shape))[:,None]]

    return rgb.reshape(shape+(3,))


def update_plot(old, new):
    """
    Updates an existing plot or figure with a new plot,
    useful for bokeh charts and mpl conversions, which do
    not allow updating an existing plot easily.

    ALERT: Should be replaced once bokeh supports it directly
    """
    old_renderers = old.select(type=GlyphRenderer)
    new_renderers = new.select(type=GlyphRenderer)

    old.x_range.update(**new.x_range.properties_with_values())
    old.y_range.update(**new.y_range.properties_with_values())
    updated = []
    for new_r in new_renderers:
        for old_r in old_renderers:
            if type(old_r.glyph) == type(new_r.glyph):
                old_renderers.pop(old_renderers.index(old_r))
                new_props = new_r.properties_with_values()
                source = new_props.pop('data_source')
                old_r.glyph.update(**new_r.glyph.properties_with_values())
                old_r.update(**new_props)
                old_r.data_source.data.update(source.data)
                updated.append(old_r)
                break

    for old_r in old_renderers:
        if old_r not in updated:
            emptied = {k: [] for k in old_r.data_source.data}
            old_r.data_source.data.update(emptied)


def pad_plots(plots, padding=0.85):
    """
    Accepts a grid of bokeh plots in form of a list of lists and
    wraps any DataTable or Tabs in a WidgetBox with appropriate
    padding. Required to avoid overlap in gridplot.
    """
    widths = []
    for row in plots:
        row_widths = []
        for p in row:
            if isinstance(p, Tabs):
                width = np.max([p.width if isinstance(p, DataTable) else
                                t.child.plot_width for t in p.tabs])
                for p in p.tabs:
                    p.width = int(padding*width)
            elif isinstance(p, DataTable):
                width = p.width
                p.width = int(padding*width)
            elif p:
                width = p.plot_width
            else:
                width = 0
            row_widths.append(width)
        widths.append(row_widths)
    plots = [[WidgetBox(p, width=w) if isinstance(p, (DataTable, Tabs)) else p
              for p, w in zip(row, ws)] for row, ws in zip(plots, widths)]
    total_width = np.max([np.sum(row) for row in widths])
    return plots, total_width

Looks like a list of things we may need to worry about maintaining over time.