matplotlib.pyplot中如何处理多维数据？

Question

I am not looking on how to visualize multi-dimensional data, but on what pyplot exactly does when multi-dimensional data is fed to it? As an example, consider this simple code:

import matplotlib.pyplot as plt
import numpy as np

X = np.array([[1,2,3],[4,3,2],[0,2,4]])
Y = np.array([1,2,3]).reshape(-1,1)

plt.plot(X, Y, 'ro', alpha=0.3)

X is a 3x3 array and Y is a 3x1 array. What I initially thought was happening was that Y would be repeated to match X's dimensions. That is, 3 scatter plots will be produced as X[0] vs Y, X[1] vs Y and X[2] vs Y and all three would be super-imposed on same x-axis. But as from the output below, if my hypothesis was correct, there would be a point at (0,1) from X[2] vs Y graph, but there isn't. Please help me out guys.

Answer 1

You can interpret the result with removing the color specifier for the marker:

import matplotlib.pyplot as plt
import numpy as np

X = np.array([[1,2,3],[4,3,2],[0,2,4]])
Y = np.array([1,2,3]).reshape(-1,1)

plt.plot(X, Y, 'o', alpha=0.3)

This will produce the figure below. We see that the blue dots were obtained with the Y coordinates and the first element of each array of X (namely, X[:, 0] ), and so on.

So plt.plot does something similar than

for x in X.T:  # .T for transposing the array
    plt.plot(x, Y, 'o', alpha=0.3)