Function scale_vec 

pub fn scale_vec(
    n: i32,
    alpha: f64,
    x: &mut [f64],
    incx: i32,
    null_mask: Option<&Bitmask>,
    null_count: Option<usize>,
) -> Result<(), KernelError>

In-place vector scaling: x ← α·x

This is the version for a matrix in a flat strided buffer, and therefore tackles incx (“increment x”) the gap between values.

Multiplies each element of the input vector x by the scalar alpha. Equivalent to x[i] ← alpha * x[i] for all valid i.