Function rstats::genvec

pub fn genvec(d: usize, n: usize, s1: u32, s2: u32) -> Vec<Vec<f64>>

Generates a vector of n vectors, each of length d, all filled with random numbers for testing. It needs two seeds s1 and s2. Same seeds will produce the same random sequence.
Uses local closure rand to generate random numbers (avoids dependencies).
Random numbers are in the open interval 0..1 with uniform distribution.