zgtcon - estimate the reciprocal of the condition number of a complex tridiagonal matrix A using the LU factorization as computed by ZGTTRF
SUBROUTINE ZGTCON(NORM, N, LOW, D, UP1, UP2, IPIVOT, ANORM, RCOND, WORK, INFO) CHARACTER*1 NORM DOUBLE COMPLEX LOW(*), D(*), UP1(*), UP2(*), WORK(*) INTEGER N, INFO INTEGER IPIVOT(*) DOUBLE PRECISION ANORM, RCOND SUBROUTINE ZGTCON_64(NORM, N, LOW, D, UP1, UP2, IPIVOT, ANORM, RCOND, WORK, INFO) CHARACTER*1 NORM DOUBLE COMPLEX LOW(*), D(*), UP1(*), UP2(*), WORK(*) INTEGER*8 N, INFO INTEGER*8 IPIVOT(*) DOUBLE PRECISION ANORM, RCOND F95 INTERFACE SUBROUTINE GTCON(NORM, N, LOW, D, UP1, UP2, IPIVOT, ANORM, RCOND, WORK, INFO) CHARACTER(LEN=1) :: NORM COMPLEX(8), DIMENSION(:) :: LOW, D, UP1, UP2, WORK INTEGER :: N, INFO INTEGER, DIMENSION(:) :: IPIVOT REAL(8) :: ANORM, RCOND SUBROUTINE GTCON_64(NORM, N, LOW, D, UP1, UP2, IPIVOT, ANORM, RCOND, WORK, INFO) CHARACTER(LEN=1) :: NORM COMPLEX(8), DIMENSION(:) :: LOW, D, UP1, UP2, WORK INTEGER(8) :: N, INFO INTEGER(8), DIMENSION(:) :: IPIVOT REAL(8) :: ANORM, RCOND C INTERFACE #include <sunperf.h> void zgtcon(char norm, int n, doublecomplex *low, doublecomplex *d, doublecomplex *up1, doublecomplex *up2, int *ipivot, double anorm, double *rcond, int *info); void zgtcon_64(char norm, long n, doublecomplex *low, doublecomplex *d, doublecomplex *up1, doublecomplex *up2, long *ipivot, double anorm, double *rcond, long *info);
Oracle Solaris Studio Performance Library zgtcon(3P) NAME zgtcon - estimate the reciprocal of the condition number of a complex tridiagonal matrix A using the LU factorization as computed by ZGTTRF SYNOPSIS SUBROUTINE ZGTCON(NORM, N, LOW, D, UP1, UP2, IPIVOT, ANORM, RCOND, WORK, INFO) CHARACTER*1 NORM DOUBLE COMPLEX LOW(*), D(*), UP1(*), UP2(*), WORK(*) INTEGER N, INFO INTEGER IPIVOT(*) DOUBLE PRECISION ANORM, RCOND SUBROUTINE ZGTCON_64(NORM, N, LOW, D, UP1, UP2, IPIVOT, ANORM, RCOND, WORK, INFO) CHARACTER*1 NORM DOUBLE COMPLEX LOW(*), D(*), UP1(*), UP2(*), WORK(*) INTEGER*8 N, INFO INTEGER*8 IPIVOT(*) DOUBLE PRECISION ANORM, RCOND F95 INTERFACE SUBROUTINE GTCON(NORM, N, LOW, D, UP1, UP2, IPIVOT, ANORM, RCOND, WORK, INFO) CHARACTER(LEN=1) :: NORM COMPLEX(8), DIMENSION(:) :: LOW, D, UP1, UP2, WORK INTEGER :: N, INFO INTEGER, DIMENSION(:) :: IPIVOT REAL(8) :: ANORM, RCOND SUBROUTINE GTCON_64(NORM, N, LOW, D, UP1, UP2, IPIVOT, ANORM, RCOND, WORK, INFO) CHARACTER(LEN=1) :: NORM COMPLEX(8), DIMENSION(:) :: LOW, D, UP1, UP2, WORK INTEGER(8) :: N, INFO INTEGER(8), DIMENSION(:) :: IPIVOT REAL(8) :: ANORM, RCOND C INTERFACE #include <sunperf.h> void zgtcon(char norm, int n, doublecomplex *low, doublecomplex *d, doublecomplex *up1, doublecomplex *up2, int *ipivot, double anorm, double *rcond, int *info); void zgtcon_64(char norm, long n, doublecomplex *low, doublecomplex *d, doublecomplex *up1, doublecomplex *up2, long *ipivot, double anorm, double *rcond, long *info); PURPOSE zgtcon estimates the reciprocal of the condition number of a complex tridiagonal matrix A using the LU factorization as computed by ZGTTRF. An estimate is obtained for norm(inv(A)), and the reciprocal of the condition number is computed as RCOND = 1 / (ANORM * norm(inv(A))). ARGUMENTS NORM (input) Specifies whether the 1-norm condition number or the infin- ity-norm condition number is required: = '1' or 'O': 1-norm; = 'I': Infinity-norm. N (input) The order of the matrix A. N >= 0. LOW (input) The (n-1) multipliers that define the matrix L from the LU factorization of A as computed by ZGTTRF. D (input) The n diagonal elements of the upper triangular matrix U from the LU factorization of A. UP1 (input) The (n-1) elements of the first superdiagonal of U. UP2 (input) The (n-2) elements of the second superdiagonal of U. IPIVOT (input) The pivot indices; for 1 <= i <= n, row i of the matrix was interchanged with row IPIVOT(i). IPIVOT(i) will always be either i or i+1; IPIVOT(i) = i indicates a row interchange was not required. ANORM (input) If NORM = '1' or 'O', the 1-norm of the original matrix A. If NORM = 'I', the infinity-norm of the original matrix A. RCOND (output) The reciprocal of the condition number of the matrix A, com- puted as RCOND = 1/(ANORM * AINVNM), where AINVNM is an esti- mate of the 1-norm of inv(A) computed in this routine. WORK (workspace) dimension(2*N) INFO (output) = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value 7 Nov 2015 zgtcon(3P)