Its size is specified by naux . The work area is deallocated before control is returned to the calling program. On Return a is the transformed matrix A of order n , containing the results of the factorization. In your C program, argument rcond must be passed by reference. You have the option of having the minimum required value for naux dynamically returned to your program.
L is a unit lower triangular matrix.
U is an upper triangular matrix. P is the permutation matrix. An estimate of the reciprocal of the condition number, rcond , and the determinant, det , can also be computed by this subroutine. If n is 0, no computation is performed. These subroutines call SGEF and DGEF, respectively, to perform the factorization.