Python all points on circle given radius and center
13,974
from itertools import product
def points_in_circle(radius):
for x, y in product(range(int(radius) + 1), repeat=2):
if x**2 + y**2 <= radius**2:
yield from set(((x, y), (x, -y), (-x, y), (-x, -y),))
list(points_in_circle(2))
[(0, 0), (0, 1), (0, -1), (0, -2), (0, 2), (1, 0), (-1, 0), (-1, 1), (1, -1), (1, 1), (-1, -1), (2, 0), (-2, 0)]
with numpy
def points_in_circle_np(radius):
a = np.arange(radius + 1)
for x, y in zip(*np.where(a[:,np.newaxis]**2 + a**2 <= radius**2)):
yield from set(((x, y), (x, -y), (-x, y), (-x, -y),))
with arbitrary center
def points_in_circle_np(radius, x0=0, y0=0, ):
x_ = np.arange(x0 - radius - 1, x0 + radius + 1, dtype=int)
y_ = np.arange(y0 - radius - 1, y0 + radius + 1, dtype=int)
x, y = np.where((x_[:,np.newaxis] - x0)**2 + (y_ - y0)**2 <= radius**2)
# x, y = np.where((np.hypot((x_-x0)[:,np.newaxis], y_-y0)<= radius)) # alternative implementation
for x, y in zip(x_[x], y_[y]):
yield x, y
Related videos on Youtube
Author by
aze45sq6d
Updated on June 04, 2022Comments
-
aze45sq6d almost 2 years
I wrote this function:
def get_x_y_co(circles): xc = circles[0] #x-co of circle (center) yc = circles[1] #y-co of circle (center) r = circles[2] #radius of circle arr=[] for i in range(360): y = yc + r*math.cos(i) x = xc+ r*math.cos(i) x=int(x) y=int(y) #Create array with all the x-co and y-co of the circle arr.append([x,y]) return arr
With 'circles' being an array with
[X-center, Y-center, Radius]
I would like to extract all the points with integer resolution present in the circle. Right now, I realised I am creating an array of points who are on the BORDER of the circle, but I don't have access to the points INSIDE the circle.
I thought of just reducing the radius, and iterate this for all values of the radius, until the radius is 0
But I feelthere is a much more efficient way. Any help is welcome
-
khelwood about 6 yearsAren't there an infinite number of points inside the circle?
-
aze45sq6dYes I do, but I have an exercise asking to calculate the average color of the circle just given the radius and the center coords. I was thinking of just extracting all the pixels in the circle, and then calculating the mean value of the BGR values
-
DeepSpaceSee stackoverflow.com/questions/15856411/… Not in Python but can be easily ported.
-
khelwoodI guess you mean points with integer resolution?
-