RANDOM_MATRIX_EIGENVALUES, a Python library which demonstrates how, for certain probability density functions (PDF's), a symmetric matrix with entries sampled from that PDF will have eigenvalues distributed according to Wigner's semicircle distribution.
The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.
RANDOM_MATRIX_EIGENVALUES is available in a Python version.
You can go up one level to the Python source codes.