如何在Python中缩放一条线的长度并获得相应的坐标（（x1，y1），（x2，y2））？

Question

I have a line with 2 sets of co-ordinates (x1, y1) and (x2, y2) corresponding to points A and B. I can calculate the Euclidean distance (L2 norm) between these 2 points using:

point_a = (189, 45)
point_b = (387, 614)
line= (point_a, point_b)
point_array = np.array(line)
distance = np.linalg.norm(point_array)
print('Euclidean distance = ', distance)```

How is it possible to obtain the co-ordinates for the line scaled about it's midpoint?
i.e. I would like to scale the length of the line but keep the angle.

Answer 1

For that you have to do it with the mid point like this.

import numpy as np

# Define the two points as a NumPy array
points = np.array([[189, 45], [387, 614]])

# Calculate the midpoint of the line
midpoint = points.mean(axis=0)

# Calculate the scaling factor
scale_factor = 2

# Scale the coordinates of the two points about the midpoint
scaled_points = midpoint + (points - midpoint) * scale_factor

# Print the scaled points
print(scaled_points)