Matplotlib: make_image() inexplicable error

Question

In the following simple matplotlib code:

import numpy as np
import matplotlib.pyplot as plt

x = np.arange(0,5,0.1)
y = np.sin(1.33*x)
x1, y1 = np.meshgrid(x, y)
data = np.sin(x1) + y1**4
im = plt.imshow(data)
x = im.make_image()
...

I get the following inexplicable error in the last statement: "TypeError: make_image() takes at least 2 arguments (1 given)" And I get an even more ridiculous error if I use an argument, e.g.

x = im.make_image(magnification=2.0)

"TypeError: make_image() takes at least 2 arguments (2 given)". This is one of the most ridilulous programming errors I have ever come upon!

Answer 1

I have found the missing ingredient: its a renderer. E.g.

r = plt.gcf().canvas.get_renderer()
x = im.make_image(r, magnification=2.0)

This works. Meanwhile, however, I found out with the help of a commentator here that this make_image function is not of any real use, and it is not much supported. Image maginifcation must be obtained with other means, e.g. axes.

So I consider the question solved. Thank you.

Answer 2

See e.g. this question for why something like

TypeError: method() takes at least n arguments (n given)

is not as ridiculous as it may sound at first sight.

Here you are calling make_image without any positional argument. The signature, however, is

make_image(renderer, magnification=1.0, unsampled=False)

So you are missing the renderer argument.

In python 3.6 the error is a little more clear. It would say something like

TypeError: make_image() missing 1 required positional argument: 'renderer'

which allows to find out the problem more easily.

Apart the question stays unclear on what the desired outcome is, so that's about what one can say at this point.