Gregory_weights         Calculate the Gregory quadrature weights for
                        equispaced integration. If f is a row vector
                        containing the function values, the integral is
                        approximated by the statement 'f %*% t(w)'
                        where w are the returned weights. Translated
                        from
                        https://www.colorado.edu/amath/sites/default/files/attached-files/gregory.pdf.
