Add error handling for NaN and invalid values in calculations:

[harryswift01]

Summary

This PR introduces error handling for invalid and edge-case values (like NaN, zero, and negative numbers), for example those in issue #7, to improve the stability and robustness of various calculation functions in the codebase. These checks ensure that invalid calculations (such as taking the square root of a negative number or dividing by zero) are caught and result in meaningful error messages, preventing runtime failures.

Changes

Error Handling for Spherical Coordinates Calculation get_sphCoord_axes:

• Added checks for division by zero and invalid values (negative values or zero) in spherical coordinate calculations.
• Prevented calculation of spherical coordinates when r2 or x2y2 is zero.

Mass and Moment of Inertia Checks in Force and Torque Calculation:

• Introduced validation for mass in get_weighted_forces to ensure it is positive before performing calculations.
• Enhanced get_weighted_torques to check for zero or invalid values in the moment of inertia tensor before performing any calculations, preventing invalid sqrt operations.

Negative Values Handling in Distance and Angle Calculations:

• Updated the distance and angle functions to handle negative values, ensuring that invalid values don’t cause errors in square root operations.

Frequency Calculation Safety Checks:

• Added validation to frequency_calculation to check for negative eigenvalues, which would have caused issues in calculating frequencies.

Impact

• The codebase will be more robust, with explicit error handling for edge cases like division by zero or negative square roots.
• The changes ensure that invalid calculations are caught early, providing meaningful error messages for debugging.
• These updates will prevent runtime errors that could arise from edge-case data inputs and improve the stability of calculations across different functions.

[jimboid]

This looks correct. I think a good thing to do tomorrow with Sarah F is have her pull the latest changes and quickly check it runs and gives the same numbers as before. So we can reference back to this point as being a good base.