TheAlgorithms/Python · error · ValueError

vol_torus() only accepts non-negative values

Error message

vol_torus() only accepts non-negative values

What it means

Raised by vol_torus(torus_radius, tube_radius) in maths/volume.py when either radius is negative. The function returns 2 * pi**2 * torus_radius * tube_radius**2; (0, 0) is valid and returns 0.0.

Source

Thrown at maths/volume.py:509

    >>> vol_torus(4, 3)
    710.6115168784338
    >>> vol_torus(3, 4)
    947.4820225045784
    >>> vol_torus(1.6, 1.6)
    80.85179925372404
    >>> vol_torus(0, 0)
    0.0
    >>> vol_torus(-1, 1)
    Traceback (most recent call last):
        ...
    ValueError: vol_torus() only accepts non-negative values
    >>> vol_torus(1, -1)
    Traceback (most recent call last):
        ...
    ValueError: vol_torus() only accepts non-negative values
    """
    if torus_radius < 0 or tube_radius < 0:
        raise ValueError("vol_torus() only accepts non-negative values")
    return 2 * pow(pi, 2) * torus_radius * pow(tube_radius, 2)


def vol_icosahedron(tri_side: float) -> float:
    """
    | Calculate the Volume of an Icosahedron.
    | Wikipedia reference: https://en.wikipedia.org/wiki/Regular_icosahedron

    >>> from math import isclose
    >>> isclose(vol_icosahedron(2.5), 34.088984228514256)
    True
    >>> isclose(vol_icosahedron(10), 2181.694990624912374)
    True
    >>> isclose(vol_icosahedron(5), 272.711873828114047)
    True
    >>> isclose(vol_icosahedron(3.49), 92.740688412033628)
    True
    >>> vol_icosahedron(0)

View on GitHub (pinned to f5988cc097)

Solutions

1. Bound parameter sweeps to non-negative ranges before calling vol_torus.
2. Validate both radii >= 0 at the point values enter your program (CLI args, config, mesh import).
3. Skip or clamp iterations that would produce negative radii rather than calling the function.

Example fix

# before
for tube_r in numpy.arange(-2, 2, 0.1):
    v = vol_torus(R, tube_r)  # ValueError on negative tube_r

# after
for tube_r in numpy.arange(0, 2, 0.1):
    v = vol_torus(R, tube_r)

if torus_radius < 0 or tube_radius < 0:
    raise ValueError(f'torus radii must be >= 0: {torus_radius}, {tube_radius}')
vol = vol_torus(torus_radius, tube_radius)

try:
    v = vol_torus(R, r)
except ValueError:
    continue  # in sweeps: skip invalid parameter combos

When it happens

Trigger: Calling vol_torus(-1, 1) or vol_torus(1, -1); torus parameters from CAD exports or parametric sweep code where one radius went negative during iteration.

Common situations: Optimization or parameter-sweep loops that step a radius through negative values; misordered arguments with a signed tube radius; unvalidated user parameters for 3D models.

Related errors

• surface_area_cube() only accepts non-negative values
• surface_area_cuboid() only accepts non-negative values
• surface_area_sphere() only accepts non-negative values
• surface_area_hemisphere() only accepts non-negative values
• surface_area_cone() only accepts non-negative values

AI-assisted analysis of TheAlgorithms/Python@f5988cc097 (2026-08-14). Data as JSON: /api/errors/8bee632012732635. Report an issue: GitHub.