/**
* <p>
* Checks to see if the matrix is positive definite.
* </p>
* <p>
* x<sup>T</sup> A x > 0<br>
* for all x where x is a non-zero vector and A is a symmetric matrix.
* </p>
*
* @param A square symmetric matrix. Not modified.
*
* @return True if it is positive definite and false if it is not.
*/
public static bool isPositiveDefinite(DMatrixSparseCSC A)
{
if (A.numRows != A.numCols)
{
return(false);
}
CholeskySparseDecomposition <DMatrixSparseCSC> chol = new CholeskyUpLooking_DSCC();
return(chol.decompose(A));
}
//@Override
public bool setA(DMatrixSparseCSC A)
{
DMatrixSparseCSC C = reduce.apply(A);
return(cholesky.decompose(C));
}
