eigen

import mir.ndslice;
import mir.math;

auto data = 
    [[ 0, 1],
     [-1, 0]].fuse.as!double.rcslice;
auto eigenvalues = [0 + 1i, 0 - 1i].sliced;
auto eigenvectors =
    [[0 - 1i, 1 + 0i],
     [0 + 1i, 1 + 0i]].fuse;

auto res = data.eigen;

assert(res.eigenvalues.equal!approxEqual(eigenvalues));
foreach (i; 0 .. eigenvectors.length)
    assert((res.eigenvectors.lightScope[i] / eigenvectors[i]).diff.slice.nrm2.approxEqual(0));

import mir.ndslice;
import mir.math;
import mir.blas;

auto data =
    [[0, 1, 0],
     [0, 0, 1],
     [1, 0, 0]].fuse.as!double.rcslice;
auto c = 3.0.sqrt;
auto eigenvalues = [(-1 + c * 1i) / 2, (-1 - c * 1i) / 2, 1 + 0i];

auto eigenvectors =
    [[-1 + c * 1i , -1 - c * 1i , 2 + 0i],
     [-1 - c * 1i , -1 + c * 1i , 2 + 0i],
     [1 + 0i, 1 + 0i, 1 + 0i]].fuse;

auto res = data.eigen;

assert(res.eigenvalues.equal!approxEqual(eigenvalues));
foreach (i; 0 .. eigenvectors.length)
    assert((res.eigenvectors.lightScope[i] / eigenvectors[i]).diff.slice.nrm2.approxEqual(0));

auto cdata = data.lightScope.as!cdouble.rcslice;
res = cdata.eigen;

assert(res.eigenvalues.equal!approxEqual(eigenvalues));
foreach (i; 0 .. eigenvectors.length)
    assert((res.eigenvectors.lightScope[i] / eigenvectors[i]).diff.slice.nrm2.approxEqual(0));