matplotlib animate imshow

[kiyoshi7]

I'm trying to animate the code below. I basically want to plot an NxM matrix with the values of -1 or 1 and run the matrix through a function to change the image over time. Can someone tell me where it's going wrong? I am using this site as an example https://matplotlib.org/examples/animatio...image.html. I tried asking at another site but the help there didn't help me all that much

this is the code I am using:

import numpy as np
import matplotlib.pyplot as plt
from matplotlib.animation import FuncAnimation


# white is + black is -
# NxM array of spins
def random_spin_field(N,M):
    return np.random.choice([-1,1], size=(N,M))

def display_spin_field(field):
    return plt.imshow(random_spin_field(1000, 1000),interpolation='nearest',cmap = 'binary')

## Ising Model
# Interaction (ferromagnetic if positive, antiferromagnetic if negative, non-ferromagnetic if zero)
Interaction = 0
# every point in the grid
def ising_step(field, beta=2): #beta is T**-1 
    N, M = field.shape 
    for n_offset in range(2): # change order to do the pixels, ie skip pixels
        for m_offset in range(2):
            for n in range(n_offset, N, 2):
                for m in range(m_offset, M, 2):
                    _ising_update(field, n, m, beta) #calculate energy
    images = field
    return im,

## this is called by ising_step()
def _ising_update(field, n, m, beta):
    total = 0   #sum of all of the spins +/-1 of the neighboring points
    N, M = field.shape
    for i in range(n-1, n+2):#####loops between the 
        for j in range(m-1, m+2):# block of 9 points including the point itself
            if i == n and j == m: #remove the point itself
                continue
            total += field[i % N, j % M] *Interaction
    dE = 2 * field[n, m] * total #compute the energy
    if dE <= 0:  #if energy is improved by switching
        field[n, m] *= -1 #switch
    elif np.exp(-dE * beta) > np.random.rand(): # prob. of switching anyway
        field[n, m] *= -1

images = [random_spin_field(100, 100)]

fig = plt.figure()
im = plt.imshow(images,interpolation='nearest',cmap = 'binary', animated=True)

ani = FuncAnimation(fig, ising_step(images[-1]), blit=True)
plt.show()

and this is the error i'm getting:

Error:
Traceback (most recent call last):
  File "C:\...\Termo3.py", line 46, in <module>
    im = plt.imshow(images,interpolation='nearest',cmap = 'binary', animated=True)
  File "C:\Users\...\Programs\Python\Python36-32\lib\site-packages\matplotlib\pyplot.py", line 3101, in imshow
    **kwargs)
  File "C:\...\Local\Programs\Python\Python36-32\lib\site-packages\matplotlib\__init__.py", line 1717, in inner
    return func(ax, *args, **kwargs)
  File "C:\...\Programs\Python\Python36-32\lib\site-packages\matplotlib\axes\_axes.py", line 5127, in imshow
    im.set_data(X)
  File "C:\...\Programs\Python\Python36-32\lib\site-packages\matplotlib\image.py", line 611, in set_data
    raise TypeError("Invalid dimensions for image data")
TypeError: Invalid dimensions for image data