/*
use faer::col::{from_slice, Col};
use faer::mat::Mat;
use faer::prelude::*;
use faer::sparse::SparseColMat;
pub struct bandec {
matrix:SparseColMat<usize, f64 >
}
impl bandec {
pub fn new(matrix:SparseColMat<usize, f64 >) -> Self {
bandec{matrix}
}
pub fn b(&mut self){
for in self.matrix. {
};
}
}
*/