code: public static DoubleMatrix solvePositive(DoubleMatrix A, DoubleMatrix B) {
  		A.assertSquare();
  		DoubleMatrix X = B.dup();
  		SimpleBlas.posv('U', A.dup(), X);
  		return X;
  	}
docs: Solves the linear equation A*X = B for symmetric and positive definite A.