如何在python中从3个数组创建颜色映射

Question

I'm trying to create a colour plot in python of two arrays t1 and t2 with the colours being set by a third one v, but I can't get the colour bar to be in terms of the v array, it is instead in terms of t1. This is my code:

    import matplotlib.pyplot as plt
    import numpy as np
    t1 = [75, 76, 77, 78]
    t2 = [75, 76, 77, 78]
    v = [0.5, 0.5, 0.8, 0.8]

    image_data = np.column_stack([t1, t2, v])
    plt.imshow(image_data)
    plt.colorbar()
    plt.show()

It produces this figure:

Any help would be much appreciated.

Answer 1

You cannot use imshow to set x and y coordinates, and color as 3rd. It is to show a matrix image, where there are X*Y values, and all these values represent color. Perhaps you want to use scatter . Eg you can try:

import matplotlib.pyplot as plt
t1 = [0,1,2,3]
t2 = [0, 10, 20, 30]
v = [0.5, 0.5, 0.8, 0.8]

plt.scatter(t1, t2, c=v, cmap='Greens')
plt.colorbar()
plt.show()

You can check which colormap is most suitable for you.