Persi Diaconis https://www.ams.org/notices/200511/what-is.pdf https://www.ams.org/notices/200511/what-is.pdf — you want to choose randomly from the eigenvalues

Persi Diaconis https://www.ams.org/notices/200511/what-is.pdf https://www.ams.org/notices/200511/what-is.pdf — you want to choose randomly from the eigenvalues of a matrix