SGETC2 computes an LU factorization with complete pivoting of the


 n-by-n matrix A. The factorization has the form A = P * L * U * Q,


 where P and Q are permutation matrices, L is lower triangular with


 unit diagonal elements and U is upper triangular.


 This is the Level 2 BLAS algorithm.

N

          N is INTEGER


          The order of the matrix A. N >= 0.

A

          A is REAL array, dimension (LDA, N)


          On entry, the n-by-n matrix A to be factored.


          On exit, the factors L and U from the factorization


          A = P*L*U*Q; the unit diagonal elements of L are not stored.


          If U(k, k) appears to be less than SMIN, U(k, k) is given the


          value of SMIN, i.e., giving a nonsingular perturbed system.

LDA

          LDA is INTEGER


          The leading dimension of the array A.  LDA >= max(1,N).

IPIV

          IPIV is INTEGER array, dimension(N).


          The pivot indices; for 1 <= i <= N, row i of the


          matrix has been interchanged with row IPIV(i).

JPIV

          JPIV is INTEGER array, dimension(N).


          The pivot indices; for 1 <= j <= N, column j of the


          matrix has been interchanged with column JPIV(j).

INFO

          INFO is INTEGER


           = 0: successful exit


           > 0: if INFO = k, U(k, k) is likely to produce overflow if


                we try to solve for x in Ax = b. So U is perturbed to


                avoid the overflow.

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Bo Kagstrom and Peter Poromaa, Department of Computing Science, Umea University, S-901 87 Umea, Sweden.