使用 Numpy 将笛卡尔坐标转换为极坐标

Question

I'm new to numpy, and I ran the following code

C = np.random.random((10,2))
X = np.copy(C[:, 0])
Y = np.copy(C[:,1])
C[:, 0] = np.sqrt(X**2+Y**2)
C[:,1] = np.arctan2(Y,X)
print(C)

X,Y = C[:,0], C[:,1]
R = np.sqrt(X**2+Y**2)
T = np.arctan2(Y,X)
print(R)
print(T)

They are 2 different ways of transforming a 10x2 matrix of cartesian coordinates to polar coordinates. The first way was my answer, the second one is the correct one. They give different outputs, and I don't understand why. Can anyone help me? Thank you

Answer 1

You modified the column values of C in

C[:, 0] = np.sqrt(X**2+Y**2)
C[:,1] = np.arctan2(Y,X)

Instead, do:

import numpy as np
C = np.random.random((10,2))
X = np.copy(C[:, 0])
Y = np.copy(C[:,1])
R = np.sqrt(X**2+Y**2)
T = np.arctan2(Y,X)
print(R)
print(T)

X,Y = C[:,0], C[:,1]
R = np.sqrt(X**2+Y**2)
T = np.arctan2(Y,X)
print(R)
print(T)