Value Error: x and y must have the same first dimension
Question: Let me quickly brief you first, I am working with a .txt file with 5400 data
points. Each is a 16 second average over a 24 hour period (24 hrs * 3600 s/hr
= 86400...86400/16 = 5400). In short this is the average magnetic strength in
the z direction for an inbound particle field curtsy of the Advanced
Composition Experiment satellite. Data publicly available
[here](http://www.srl.caltech.edu/ACE/ASC/level2/index.html). So when I try to
plot it says the error

    
    
    Value Error: x and y must have the same first dimension
    

So I created a numpy lin space of 5400 points broken apart by 16 units. I did
this because I thought that my dimensions didn't match with my previous array
that I had defined. But now I am sure these two array's are of the same
dimension and yet it still gives back that Value Error. The code is as
follows:

**First try (without the linspace):**

    
    
    import numpy as np
    import matplotlib as plt
    
    Bz = np.loadtxt(r"C:\Users\Schmidt\Desktop\Project\Data\ACE\MAG\ACE_MAG_Data_20151202_GSM.txt", dtype = bytes).astype(float)
    
    Start_ACE = dt.date(2015,12,2)
    Finish_ACE = dt.date(2015,12,2)
    
    dt_Mag = 16
    
    time_Mag = np.arange(Start_ACE, Finish_ACE, dt_Mag)
    
    plt.subplot(3,1,1)
    plt.plot(time_Mag, Bz)
    plt.title('Bz 2015 12 02')
    

**Second Try (with linspace):**

    
    
    import numpy as np
    import matplotlib as plt
    
    Bz = np.loadtxt(r"C:\Users\Schmidt\Desktop\Project\Data\ACE\MAG\ACE_MAG_Data_20151202_GSM.txt", dtype = bytes).astype(float)
    
    Mag_time = np.linspace(0,5399,16, dtype = float)
    
    plt.subplot(3,1,1)
    plt.plot(Mag_time, Bz)
    plt.title('Bz 2015 12 02')
    

Other than it being a dimensional problem I don't know what else could be
holding back this plotting procedure back.

**Full traceback:**

    
    
    ValueError                                Traceback (most recent call last)
    <ipython-input-68-c5dc0bdf5117> in <module>()
          1 plt.subplot(3,1,1)
    ----> 2 plt.plot(Mag_time, Bz)
          3 plt.title('Bz 2015 12 02')
    
    C:\Users\Schmidt\Anaconda3\lib\site-packages\matplotlib\pyplot.py in plot(*args, **kwargs)
       3152         ax.hold(hold)
       3153     try:
    -> 3154         ret = ax.plot(*args, **kwargs)
       3155     finally:
       3156         ax.hold(washold)
    
    C:\Users\Schmidt\Anaconda3\lib\site-packages\matplotlib\__init__.py in inner(ax, *args, **kwargs)
       1809                     warnings.warn(msg % (label_namer, func.__name__),
       1810                                   RuntimeWarning, stacklevel=2)
    -> 1811             return func(ax, *args, **kwargs)
       1812         pre_doc = inner.__doc__
       1813         if pre_doc is None:
    
    C:\Users\Schmidt\Anaconda3\lib\site-packages\matplotlib\axes\_axes.py in plot(self, *args, **kwargs)
       1422             kwargs['color'] = c
       1423 
    -> 1424         for line in self._get_lines(*args, **kwargs):
       1425             self.add_line(line)
       1426             lines.append(line)
    
    C:\Users\Schmidt\Anaconda3\lib\site-packages\matplotlib\axes\_base.py in _grab_next_args(self, *args, **kwargs)
        384                 return
        385             if len(remaining) <= 3:
    --> 386                 for seg in self._plot_args(remaining, kwargs):
        387                     yield seg
        388                 return
    
    C:\Users\Schmidt\Anaconda3\lib\site-packages\matplotlib\axes\_base.py in _plot_args(self, tup, kwargs)
        362             x, y = index_of(tup[-1])
        363 
    --> 364         x, y = self._xy_from_xy(x, y)
        365 
        366         if self.command == 'plot':
    
    C:\Users\Schmidt\Anaconda3\lib\site-packages\matplotlib\axes\_base.py in _xy_from_xy(self, x, y)
        221         y = _check_1d(y)
        222         if x.shape[0] != y.shape[0]:
    --> 223             raise ValueError("x and y must have same first dimension")
        224         if x.ndim > 2 or y.ndim > 2:
        225             raise ValueError("x and y can be no greater than 2-D")
    
    ValueError: x and y must have same first dimension
    


Answer: The problem was the selection of array creation. Instead of linspace, I should
have used arange.

    
    
    Mag_time = np.arange(0,86400, 16, dtype = float)
    

