Allows the user to construct a matrix with prescribed eigenvalues and singular values.
The eigenvalues may be positive, negative, or complex. If complex they may be single or in conjugate pairs.
The result will be in upper triangular (real) Schur form.
This program has extended functionality from the original program by Chi-Kwong Li and Roy Mathias, The College of William and Mary. http://people.wm.edu/~cklixx/higham.pdf
Paul Godfrey (2020). evsv (https://www.mathworks.com/matlabcentral/fileexchange/72981-evsv), MATLAB Central File Exchange. Retrieved .