How can I generate x, y coordinate pairs for a perfect circle of grid cells, for a specific number of cells?

Question

Given a list of data like this, I want to be able to generate sets of x & y coordinate pairs in the shape of a circle:

test_data = list(range(121))

Currently I am manually calculating the coordinates for the circle like this:

# Num cells per row
n_cells = [3, 7, 9, 11, 11, 13]
n_cells = n_cells + [13] + n_cells[::-1]
grid_size = [max(n_cells)] * 2

coords = []
for column, row in enumerate(n_cells):
    cells_c = (grid_size[0] - row) // 2
    for i in range(row):
        coords = coords + [[cells_c + i, column]]

The above example gives a shape of grid cells that looks like this:

I would like to recreate the above example without using hardcoded numbers, so I can easily plug in test data with more or less items than 121.

Answer 1

Maybe you can use this as a starting point:

import math

def circle(radius):
    for y in range(-radius, radius+1):
        for x in range(-radius, radius+1):
            if math.sqrt(y*y+x*x) <= radius:
                print("X",end='')
            else:
                print(" ",end='')
        print()

circle(25)

Output:

                         X                         
                  XXXXXXXXXXXXXXX                  
                XXXXXXXXXXXXXXXXXXX                
              XXXXXXXXXXXXXXXXXXXXXXX              
            XXXXXXXXXXXXXXXXXXXXXXXXXXX            
          XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX          
         XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX         
        XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX        
       XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX       
      XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX      
     XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX     
     XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX     
    XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX    
    XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX    
   XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX   
   XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX   
  XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX  
  XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX  
 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 
 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 
 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 
 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 
 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 
 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 
 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 
 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 
 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 
 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 
 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 
 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 
 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 
  XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX  
  XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX  
   XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX   
   XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX   
    XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX    
    XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX    
     XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX     
     XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX     
      XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX      
       XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX       
        XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX        
         XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX         
          XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX          
            XXXXXXXXXXXXXXXXXXXXXXXXXXX            
              XXXXXXXXXXXXXXXXXXXXXXX              
                XXXXXXXXXXXXXXXXXXX                
                  XXXXXXXXXXXXXXX                  
                         X