Python3: print respective x and y coordinate of a NumPy array-CodePudding

Let's say I have a Python script like that

import numpy as np
positions = np.array([[2.5, 8], [3, 10], [0, 5], [1, 5]])
x = positions[:, 0]
y = positions[:, 1]

def isInside(circle_x, circle_y, rad, x, y):
   return ((x - circle_x) ** 2   (y - circle_y) ** 2) <= rad ** 2

circle_x = 0;
circle_y = 5;
rad = 2;

for is_inside in isInside(circle_x, circle_y, rad, x, y):
  print ("Inside" if is_inside else "Outside")

I now want to print the respective x and y coordinates also for each individual "Inside" or "Outside". This should look like this

[2.5, 8] Outside, [3, 10] Outside, [0, 5] Inside, [1, 5] Inside

How can I do this? Can anyone help me out?

CodePudding user response：

If you are interested in getting the x,y coordinates as well as checking to be inside or outside of the area, you can change your function to return a tuple that contains 3 values: x,y, boolean. I have edited your code and come up with the code below:

import numpy as np
positions = np.array([[2.5, 8], [3, 10], [0, 5], [1, 5]])
x = positions[:, 0]
y = positions[:, 1]

def isInside(circle_x, circle_y, rad, x, y):
   return (x,y,((x - circle_x) ** 2   (y - circle_y) ** 2) <= rad ** 2)

circle_x = 0;
circle_y = 5;
rad = 2;
is_inside = isInside(circle_x, circle_y, rad, x, y)
output = ""
for index in range(len(is_inside[2])):
  output  = "[{x}, {y}] Inside,".format(x=is_inside[0][index], y=is_inside[1][index]) if is_inside[2][index] else "[{x}, {y}] Outside,".format(x=is_inside[0][index], y=is_inside[1][index])
print(output.strip(","))

Output

[2.5, 8.0] Outside,[3.0, 10.0] Outside,[0.0, 5.0] Inside,[1.0, 5.0] Inside

A side note: You can use shapely module in order to work with geospatial structures. In this module, you can check whether a point (defined with coordinates) is in a area (defines as polygon) using within function.

CodePudding user response：

import numpy as np

positions = np.array([[2.5, 8], [3, 10], [0, 5], [1, 5]])

circle_centre = np.array((0, 5))
rad = 2

print(*(f"[{x}, {y}] {('Outside', 'Inside')[is_inside]}"
        for x, y, is_inside in zip(*np.transpose(positions), ((positions - circle_centre) ** 2).sum(1) <= rad ** 2)),
      sep=", ")