Function linear_weight 

pub fn linear_weight(x1: f64, x2: f64, x: f64) -> f64

Calculates the interpolation weight between x1 and x2 for a value x.

The returned weight w satisfies y = (1 - w) * y1 + w * y2 when interpolating ordinates that correspond to abscissas x1 and x2.

Panics

• If any input is NaN or infinite.
• If x1 and x2 are too close (within machine epsilon), which would cause division by zero or numerical instability.