Python: Creating a 2D histogram from a numpy matrix

Question

I\'m new to python.

I have a numpy matrix, of dimensions 42x42, with values in the range 0-996. I want to create a 2D histogram using this data. I\'ve been looking a

Answer 1

If you have not only the 2D histogram matrix but also the underlying (x, y) data, then you could make a scatter plot of the (x, y) points and color each point according to its binned count value in the 2D-histogram matrix:

import numpy as np
import matplotlib.pyplot as plt

n = 10000
x = np.random.standard_normal(n)
y = 2.0 + 3.0 * x + 4.0 * np.random.standard_normal(n)
xedges, yedges = np.linspace(-4, 4, 42), np.linspace(-25, 25, 42)
hist, xedges, yedges = np.histogram2d(x, y, (xedges, yedges))
xidx = np.clip(np.digitize(x, xedges), 0, hist.shape[0]-1)
yidx = np.clip(np.digitize(y, yedges), 0, hist.shape[1]-1)
c = hist[xidx, yidx]
plt.scatter(x, y, c=c)

plt.show()

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