Why does pcolor output a mirrored array in this example?

Question

array = np.eye(5)
plt.pcolor(array)

If you were to do this code, the output graph would actually be a mirror of the defined array. why is that?

Answer 1

It just draws from the bottom left, which make quite sense if you check out the labeling on the x&y-axes. Check out documentation You can invert it though:

1. by flipping the y-axis

   plt.gca().invert_yaxis()

2. or by changing your input matrix (if appropriate ...)

   plt.pcolor(np.eye(5)[::-1,:])