TheAlgorithms/Python · error · ValueError

Tangential Force cannot be negative

Error message

Tangential Force cannot be negative

What it means

Raised by shear_stress() when tangential_force is negative (and exactly one argument is 0, with stress >= 0). Force magnitude must be non-negative in this model; the check is second in the elif chain, so it fires only when stress is not negative.

Source

Thrown at physics/shear_stress.py:36

    This function can calculate any one of the three -
    1. Shear Stress
    2. Tangential Force
    3. Cross-sectional Area
    This is calculated from the other two provided values
    Examples -
    >>> shear_stress(stress=25, tangential_force=100, area=0)
    ('area', 4.0)
    >>> shear_stress(stress=0, tangential_force=1600, area=200)
    ('stress', 8.0)
    >>> shear_stress(stress=1000, tangential_force=0, area=1200)
    ('tangential_force', 1200000)
    """
    if (stress, tangential_force, area).count(0) != 1:
        raise ValueError("You cannot supply more or less than 2 values")
    elif stress < 0:
        raise ValueError("Stress cannot be negative")
    elif tangential_force < 0:
        raise ValueError("Tangential Force cannot be negative")
    elif area < 0:
        raise ValueError("Area cannot be negative")
    elif stress == 0:
        return (
            "stress",
            tangential_force / area,
        )
    elif tangential_force == 0:
        return (
            "tangential_force",
            stress * area,
        )
    else:
        return (
            "area",
            tangential_force / stress,
        )

View on GitHub (pinned to f5988cc097)

Solutions

1. Pass the force magnitude: shear_stress(stress=1000, tangential_force=abs(force), area=1200)
2. Strip directional signs from vector components before extracting the scalar magnitude
3. Validate force >= 0 at the data boundary in load-case pipelines

Example fix

# before
shear_stress(stress=1000, tangential_force=-500, area=0)
# ValueError: Tangential Force cannot be negative

# after
shear_stress(stress=1000, tangential_force=abs(-500), area=0)

if tangential_force < 0:
    tangential_force = abs(tangential_force)  # if sign encoded direction only
shear_stress(stress, tangential_force, area)

try:
    shear_stress(stress, tangential_force, area)
except ValueError as e:
    if "Tangential Force" in str(e):
        shear_stress(stress, abs(tangential_force), area)
    else:
        raise

When it happens

Trigger: shear_stress(stress=1000, tangential_force=-500, area=0) — negative force with area as the unknown; forces from a physics engine where direction is encoded in the sign.

Common situations: Signed force vectors ( opposing loads coded negative) passed as scalars; load-case tables mixing positive/negative directions; typos in hand-entered force data.

Related errors

• Gravitational force can not be negative
• Distance can not be negative
• Mass can not be negative
• The length should be non-negative
• The mass of a body cannot be negative

AI-assisted analysis of TheAlgorithms/Python@f5988cc097 (2026-08-14). Data as JSON: /api/errors/48d69453b280a466. Report an issue: GitHub.