%PD_CHECK Check whether the input matrix is positive definite%%  OK = PD_CHECK(A)%% INPUT%   A   Symmetric matrix%% OUTPUT%   OK  1/0 to indicate whether A is positive definite%% DESCRIPTION% Symmetric matrix A is positive definite, if the diagonal of A is % dominant, i.e. A(i,i) > sum_{j ~= i}  A(i,j).% Based on Golub's version of Cholesky, with non-positivity test.%% REFERENCES% G. Golub and C.V. Loan, Matrix Computations, The Johns Hopkins % University Press, Baltimore, 1989.