SUBROUTINE ZGTCON( NORM, N, LOW, DIAG, UP1, UP2, IPIVOT, ANORM, * RCOND, WORK, INFO) CHARACTER * 1 NORM DOUBLE COMPLEX LOW(*), DIAG(*), UP1(*), UP2(*), WORK(*) INTEGER N, INFO INTEGER IPIVOT(*) DOUBLE PRECISION ANORM, RCOND SUBROUTINE ZGTCON_64( NORM, N, LOW, DIAG, UP1, UP2, IPIVOT, ANORM, * RCOND, WORK, INFO) CHARACTER * 1 NORM DOUBLE COMPLEX LOW(*), DIAG(*), UP1(*), UP2(*), WORK(*) INTEGER*8 N, INFO INTEGER*8 IPIVOT(*) DOUBLE PRECISION ANORM, RCOND
SUBROUTINE GTCON( NORM, [N], LOW, DIAG, UP1, UP2, IPIVOT, ANORM, * RCOND, [WORK], [INFO]) CHARACTER(LEN=1) :: NORM COMPLEX(8), DIMENSION(:) :: LOW, DIAG, UP1, UP2, WORK INTEGER :: N, INFO INTEGER, DIMENSION(:) :: IPIVOT REAL(8) :: ANORM, RCOND SUBROUTINE GTCON_64( NORM, [N], LOW, DIAG, UP1, UP2, IPIVOT, ANORM, * RCOND, [WORK], [INFO]) CHARACTER(LEN=1) :: NORM COMPLEX(8), DIMENSION(:) :: LOW, DIAG, UP1, UP2, WORK INTEGER(8) :: N, INFO INTEGER(8), DIMENSION(:) :: IPIVOT REAL(8) :: ANORM, RCOND
void zgtcon(char norm, int n, doublecomplex *low, doublecomplex *diag, doublecomplex *up1, doublecomplex *up2, int *ipivot, double anorm, double *rcond, int *info);
void zgtcon_64(char norm, long n, doublecomplex *low, doublecomplex *diag, doublecomplex *up1, doublecomplex *up2, long *ipivot, double anorm, double *rcond, long *info);
An estimate is obtained for norm(inv(A)), and the reciprocal of the condition number is computed as RCOND = 1 / (ANORM * norm(inv(A))).