getc2(3)

NAME
getc2 - getc2: triangular factor, with complete pivoting

SYNOPSIS

  Functions
subroutine cgetc2 (n, a, lda, ipiv, jpiv, info)
CGETC2 computes the LU factorization with complete pivoting of the general n-by-n matrix.
subroutine dgetc2 (n, a, lda, ipiv, jpiv, info)
DGETC2 computes the LU factorization with complete pivoting of the general n-by-n matrix.
subroutine sgetc2 (n, a, lda, ipiv, jpiv, info)
SGETC2 computes the LU factorization with complete pivoting of the general n-by-n matrix.
subroutine zgetc2 (n, a, lda, ipiv, jpiv, info)
ZGETC2 computes the LU factorization with complete pivoting of the general n-by-n matrix.

Detailed Description

Function Documentation

  subroutine cgetc2 (integer n, complex, dimension( lda, * ) a, integer lda, integer, dimension( * ) ipiv, integer, dimension( * ) jpiv, integer info)

CGETC2 computes the LU factorization with complete pivoting of the general n-by-n matrix.

Purpose:

     CGETC2 computes an LU factorization, using 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 a level 1 BLAS version of the algorithm.

Parameters
    N

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

    A

              A is COMPLEX array, dimension (LDA, N)
              On entry, the n-by-n matrix 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, 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
                    one tries to solve for x in Ax = b. So U is perturbed
                    to avoid the overflow.

Author
    Univ. of Tennessee

    Univ. of California Berkeley

    Univ. of Colorado Denver

    NAG Ltd.

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

Definition at line 110 of file cgetc2.f.

  subroutine dgetc2 (integer n, double precision, dimension( lda, * ) a, integer lda, integer, dimension( * ) ipiv, integer, dimension( * ) jpiv, integer info)

DGETC2 computes the LU factorization with complete pivoting of the general n-by-n matrix.

Purpose:

     DGETC2 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.

Parameters
    N

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

    A

              A is DOUBLE PRECISION 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.

Author
    Univ. of Tennessee

    Univ. of California Berkeley

    Univ. of Colorado Denver

    NAG Ltd.

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

Definition at line 110 of file dgetc2.f.

  subroutine sgetc2 (integer n, real, dimension( lda, * ) a, integer lda, integer, dimension( * ) ipiv, integer, dimension( * ) jpiv, integer info)

SGETC2 computes the LU factorization with complete pivoting of the general n-by-n matrix.

Purpose:

     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.

Parameters
    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.

Author
    Univ. of Tennessee

    Univ. of California Berkeley

    Univ. of Colorado Denver

    NAG Ltd.

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

Definition at line 110 of file sgetc2.f.

  subroutine zgetc2 (integer n, complex*16, dimension( lda, * ) a, integer lda, integer, dimension( * ) ipiv, integer, dimension( * ) jpiv, integer info)

ZGETC2 computes the LU factorization with complete pivoting of the general n-by-n matrix.

Purpose:

     ZGETC2 computes an LU factorization, using 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 a level 1 BLAS version of the algorithm.

Parameters
    N

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

    A

              A is COMPLEX*16 array, dimension (LDA, N)
              On entry, the n-by-n matrix 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, 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
                    one tries to solve for x in Ax = b. So U is perturbed
                    to avoid the overflow.

Author
    Univ. of Tennessee

    Univ. of California Berkeley

    Univ. of Colorado Denver

    NAG Ltd.

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

Definition at line 110 of file zgetc2.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.