Mercurial > repos > public > sbplib

view +sbp/diagInd.m @ 1154:3108963cc42c feature/rv

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Improve efficiency of diffOps in Burgers2d, the artificial diffusion operator in rv.constructDiffOps and the RungekuttaExteriorRv time-steppers
author Vidar Stiernström <vidar.stiernstrom@it.uu.se>
date Wed, 06 Mar 2019 09:45:52 +0100
parents 32b39dc44474
children
line wrap: on
line source

function A = diagInd(d,n,m)
    A = zeros(n,length(d));
    for i = 1:length(d)
        i0 = 1;
        j0 = d(i)+1;

        I = i0 + (0:(n-1))';
        J = j0 + (0:(n-1))';

        A(:,i) = matInd2VecInd(I,J,n);

    end
end

function I = matInd2VecInd(i,j,n)
    I = i + (j-1)*n;
end