Open the context
Choose the project folder and name the files or behavior involved.
Workflows
Coding workflows · Exact triangle barycentric coordinates
03
A concrete starting point
Compute exact barycentric weights from three integer vertices and an integer point with coordinate magnitudes at most 10000. Test a vertex and an outside point, rejecting collinear vertices and verifying that the weights reconstruct the point.
Define the change
Describe the input, expected output and boundaries that must stay intact.
Inspect the work
Review the proposed edits and any commands before relying on their result.
Check the outcome
Compare actual behavior with the expected result. If a check fails, investigate it before applying more changes.
Exact triangle barycentric coordinates
A concrete starting point
from fractions import Fraction
def barycentric(vertices, point):
vertices, point = tuple(tuple(v) for v in vertices), tuple(point)
if len(vertices) != 3 or any(len(v) != 2 for v in vertices) or len(point) != 2:
raise ValueError("triangle.shape")
if any(type(c) is not int or abs(c) > 10000 for v in vertices + (point,) for c in v):
raise ValueError("coordinate.range")
(x0, y0), (x1, y1), (x2, y2) = vertices
x, y = point
den = (y1-y2)*(x0-x2) + (x2-x1)*(y0-y2)
if den == 0:
raise ValueError("triangle.degenerate")
a = Fraction((y1-y2)*(x-x2) + (x2-x1)*(y-y2), den)
b = Fraction((y2-y0)*(x-x2) + (x0-x2)*(y-y2), den)
return a, b, 1-a-bThe example is a starting point for a real project, not a claim that generated code is already tested. Adjust paths, dependencies and expected behavior to match your application.