--- name: "la_hercond" section: "3" platform: "linux" package: "lapack-doc" version: "3.12.1-2" release: "Arch Linux 2026-11-01" platforms: ["linux"] url: "https://new.carta.tech/la_hercond" --- # la\_hercond(3) la\_hercond: Skeel condition number estimate ## NAME la\_hercond - la\_hercond: Skeel condition number estimate ## SYNOPSIS ### Functions real function **cla\_hercond\_c** (uplo, n, a, lda, af, ldaf, ipiv, c, capply, info, work, rwork)\ **CLA\_HERCOND\_C** computes the infinity norm condition number of op(A)\*inv(diag(c)) for Hermitian indefinite matrices. real function **cla\_hercond\_x** (uplo, n, a, lda, af, ldaf, ipiv, x, info, work, rwork)\ **CLA\_HERCOND\_X** computes the infinity norm condition number of op(A)\*diag(x) for Hermitian indefinite matrices. real function **cla\_syrcond\_c** (uplo, n, a, lda, af, ldaf, ipiv, c, capply, info, work, rwork)\ **CLA\_SYRCOND\_C** computes the infinity norm condition number of op(A)\*inv(diag(c)) for symmetric indefinite matrices. real function **cla\_syrcond\_x** (uplo, n, a, lda, af, ldaf, ipiv, x, info, work, rwork)\ **CLA\_SYRCOND\_X** computes the infinity norm condition number of op(A)\*diag(x) for symmetric indefinite matrices. double precision function **dla\_syrcond** (uplo, n, a, lda, af, ldaf, ipiv, cmode, c, info, work, iwork)\ **DLA\_SYRCOND** estimates the Skeel condition number for a symmetric indefinite matrix. real function **sla\_syrcond** (uplo, n, a, lda, af, ldaf, ipiv, cmode, c, info, work, iwork)\ **SLA\_SYRCOND** estimates the Skeel condition number for a symmetric indefinite matrix. double precision function **zla\_hercond\_c** (uplo, n, a, lda, af, ldaf, ipiv, c, capply, info, work, rwork)\ **ZLA\_HERCOND\_C** computes the infinity norm condition number of op(A)\*inv(diag(c)) for Hermitian indefinite matrices. double precision function **zla\_hercond\_x** (uplo, n, a, lda, af, ldaf, ipiv, x, info, work, rwork)\ **ZLA\_HERCOND\_X** computes the infinity norm condition number of op(A)\*diag(x) for Hermitian indefinite matrices. double precision function **zla\_syrcond\_c** (uplo, n, a, lda, af, ldaf, ipiv, c, capply, info, work, rwork)\ **ZLA\_SYRCOND\_C** computes the infinity norm condition number of op(A)\*inv(diag(c)) for symmetric indefinite matrices. double precision function **zla\_syrcond\_x** (uplo, n, a, lda, af, ldaf, ipiv, x, info, work, rwork)\ **ZLA\_SYRCOND\_X** computes the infinity norm condition number of op(A)\*diag(x) for symmetric indefinite matrices. ## Detailed Description ## Function Documentation ### real function cla\_hercond\_c (character uplo, integer n, complex, dimension( lda, \* ) a, integer lda, complex, dimension( ldaf, \* ) af, integer ldaf, integer, dimension( \* ) ipiv, real, dimension ( \* ) c, logical capply, integer info, complex, dimension( \* ) work, real, dimension( \* ) rwork) **CLA\_HERCOND\_C** computes the infinity norm condition number of op(A)\*inv(diag(c)) for Hermitian indefinite matrices. **Purpose:** ``` !> !> CLA_HERCOND_C computes the infinity norm condition number of !> op(A) * inv(diag(C)) where C is a REAL vector. !> ``` **Parameters** *UPLO* ``` !> UPLO is CHARACTER*1 !> = 'U': Upper triangle of A is stored; !> = 'L': Lower triangle of A is stored. !> ``` *N* ``` !> N is INTEGER !> The number of linear equations, i.e., the order of the !> matrix A. N >= 0. !> ``` *A* ``` !> A is COMPLEX array, dimension (LDA,N) !> On entry, the N-by-N matrix A !> ``` *LDA* ``` !> LDA is INTEGER !> The leading dimension of the array A. LDA >= max(1,N). !> ``` *AF* ``` !> AF is COMPLEX array, dimension (LDAF,N) !> The block diagonal matrix D and the multipliers used to !> obtain the factor U or L as computed by CHETRF. !> ``` *LDAF* ``` !> LDAF is INTEGER !> The leading dimension of the array AF. LDAF >= max(1,N). !> ``` *IPIV* ``` !> IPIV is INTEGER array, dimension (N) !> Details of the interchanges and the block structure of D !> as determined by CHETRF. !> ``` *C* ``` !> C is REAL array, dimension (N) !> The vector C in the formula op(A) * inv(diag(C)). !> ``` *CAPPLY* ``` !> CAPPLY is LOGICAL !> If .TRUE. then access the vector C in the formula above. !> ``` *INFO* ``` !> INFO is INTEGER !> = 0: Successful exit. !> i > 0: The ith argument is invalid. !> ``` *WORK* ``` !> WORK is COMPLEX array, dimension (2*N). !> Workspace. !> ``` *RWORK* ``` !> RWORK is REAL array, dimension (N). !> Workspace. !> ``` **Author** Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Definition at line **136** of file **cla\_hercond\_c.f**. ### real function cla\_hercond\_x (character uplo, integer n, complex, dimension( lda, \* ) a, integer lda, complex, dimension( ldaf, \* ) af, integer ldaf, integer, dimension( \* ) ipiv, complex, dimension( \* ) x, integer info, complex, dimension( \* ) work, real, dimension( \* ) rwork) **CLA\_HERCOND\_X** computes the infinity norm condition number of op(A)\*diag(x) for Hermitian indefinite matrices. **Purpose:** ``` !> !> CLA_HERCOND_X computes the infinity norm condition number of !> op(A) * diag(X) where X is a COMPLEX vector. !> ``` **Parameters** *UPLO* ``` !> UPLO is CHARACTER*1 !> = 'U': Upper triangle of A is stored; !> = 'L': Lower triangle of A is stored. !> ``` *N* ``` !> N is INTEGER !> The number of linear equations, i.e., the order of the !> matrix A. N >= 0. !> ``` *A* ``` !> A is COMPLEX array, dimension (LDA,N) !> On entry, the N-by-N matrix A. !> ``` *LDA* ``` !> LDA is INTEGER !> The leading dimension of the array A. LDA >= max(1,N). !> ``` *AF* ``` !> AF is COMPLEX array, dimension (LDAF,N) !> The block diagonal matrix D and the multipliers used to !> obtain the factor U or L as computed by CHETRF. !> ``` *LDAF* ``` !> LDAF is INTEGER !> The leading dimension of the array AF. LDAF >= max(1,N). !> ``` *IPIV* ``` !> IPIV is INTEGER array, dimension (N) !> Details of the interchanges and the block structure of D !> as determined by CHETRF. !> ``` *X* ``` !> X is COMPLEX array, dimension (N) !> The vector X in the formula op(A) * diag(X). !> ``` *INFO* ``` !> INFO is INTEGER !> = 0: Successful exit. !> i > 0: The ith argument is invalid. !> ``` *WORK* ``` !> WORK is COMPLEX array, dimension (2*N). !> Workspace. !> ``` *RWORK* ``` !> RWORK is REAL array, dimension (N). !> Workspace. !> ``` **Author** Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Definition at line **129** of file **cla\_hercond\_x.f**. ### real function cla\_syrcond\_c (character uplo, integer n, complex, dimension( lda, \* ) a, integer lda, complex, dimension( ldaf, \* ) af, integer ldaf, integer, dimension( \* ) ipiv, real, dimension( \* ) c, logical capply, integer info, complex, dimension( \* ) work, real, dimension( \* ) rwork) **CLA\_SYRCOND\_C** computes the infinity norm condition number of op(A)\*inv(diag(c)) for symmetric indefinite matrices. **Purpose:** ``` !> !> CLA_SYRCOND_C Computes the infinity norm condition number of !> op(A) * inv(diag(C)) where C is a REAL vector. !> ``` **Parameters** *UPLO* ``` !> UPLO is CHARACTER*1 !> = 'U': Upper triangle of A is stored; !> = 'L': Lower triangle of A is stored. !> ``` *N* ``` !> N is INTEGER !> The number of linear equations, i.e., the order of the !> matrix A. N >= 0. !> ``` *A* ``` !> A is COMPLEX array, dimension (LDA,N) !> On entry, the N-by-N matrix A !> ``` *LDA* ``` !> LDA is INTEGER !> The leading dimension of the array A. LDA >= max(1,N). !> ``` *AF* ``` !> AF is COMPLEX array, dimension (LDAF,N) !> The block diagonal matrix D and the multipliers used to !> obtain the factor U or L as computed by CSYTRF. !> ``` *LDAF* ``` !> LDAF is INTEGER !> The leading dimension of the array AF. LDAF >= max(1,N). !> ``` *IPIV* ``` !> IPIV is INTEGER array, dimension (N) !> Details of the interchanges and the block structure of D !> as determined by CSYTRF. !> ``` *C* ``` !> C is REAL array, dimension (N) !> The vector C in the formula op(A) * inv(diag(C)). !> ``` *CAPPLY* ``` !> CAPPLY is LOGICAL !> If .TRUE. then access the vector C in the formula above. !> ``` *INFO* ``` !> INFO is INTEGER !> = 0: Successful exit. !> i > 0: The ith argument is invalid. !> ``` *WORK* ``` !> WORK is COMPLEX array, dimension (2*N). !> Workspace. !> ``` *RWORK* ``` !> RWORK is REAL array, dimension (N). !> Workspace. !> ``` **Author** Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Definition at line **136** of file **cla\_syrcond\_c.f**. ### real function cla\_syrcond\_x (character uplo, integer n, complex, dimension( lda, \* ) a, integer lda, complex, dimension( ldaf, \* ) af, integer ldaf, integer, dimension( \* ) ipiv, complex, dimension( \* ) x, integer info, complex, dimension( \* ) work, real, dimension( \* ) rwork) **CLA\_SYRCOND\_X** computes the infinity norm condition number of op(A)\*diag(x) for symmetric indefinite matrices. **Purpose:** ``` !> !> CLA_SYRCOND_X Computes the infinity norm condition number of !> op(A) * diag(X) where X is a COMPLEX vector. !> ``` **Parameters** *UPLO* ``` !> UPLO is CHARACTER*1 !> = 'U': Upper triangle of A is stored; !> = 'L': Lower triangle of A is stored. !> ``` *N* ``` !> N is INTEGER !> The number of linear equations, i.e., the order of the !> matrix A. N >= 0. !> ``` *A* ``` !> A is COMPLEX array, dimension (LDA,N) !> On entry, the N-by-N matrix A. !> ``` *LDA* ``` !> LDA is INTEGER !> The leading dimension of the array A. LDA >= max(1,N). !> ``` *AF* ``` !> AF is COMPLEX array, dimension (LDAF,N) !> The block diagonal matrix D and the multipliers used to !> obtain the factor U or L as computed by CSYTRF. !> ``` *LDAF* ``` !> LDAF is INTEGER !> The leading dimension of the array AF. LDAF >= max(1,N). !> ``` *IPIV* ``` !> IPIV is INTEGER array, dimension (N) !> Details of the interchanges and the block structure of D !> as determined by CSYTRF. !> ``` *X* ``` !> X is COMPLEX array, dimension (N) !> The vector X in the formula op(A) * diag(X). !> ``` *INFO* ``` !> INFO is INTEGER !> = 0: Successful exit. !> i > 0: The ith argument is invalid. !> ``` *WORK* ``` !> WORK is COMPLEX array, dimension (2*N). !> Workspace. !> ``` *RWORK* ``` !> RWORK is REAL array, dimension (N). !> Workspace. !> ``` **Author** Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Definition at line **129** of file **cla\_syrcond\_x.f**. ### double precision function dla\_syrcond (character uplo, integer n, double precision, dimension( lda, \* ) a, integer lda, double precision, dimension( ldaf, \* ) af, integer ldaf, integer, dimension( \* ) ipiv, integer cmode, double precision, dimension( \* ) c, integer info, double precision, dimension( \* ) work, integer, dimension( \* ) iwork) **DLA\_SYRCOND** estimates the Skeel condition number for a symmetric indefinite matrix. **Purpose:** ``` !> !> DLA_SYRCOND estimates the Skeel condition number of op(A) * op2(C) !> where op2 is determined by CMODE as follows !> CMODE = 1 op2(C) = C !> CMODE = 0 op2(C) = I !> CMODE = -1 op2(C) = inv(C) !> The Skeel condition number cond(A) = norminf( |inv(A)||A| ) !> is computed by computing scaling factors R such that !> diag(R)*A*op2(C) is row equilibrated and computing the standard !> infinity-norm condition number. !> ``` **Parameters** *UPLO* ``` !> UPLO is CHARACTER*1 !> = 'U': Upper triangle of A is stored; !> = 'L': Lower triangle of A is stored. !> ``` *N* ``` !> N is INTEGER !> The number of linear equations, i.e., 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. !> ``` *LDA* ``` !> LDA is INTEGER !> The leading dimension of the array A. LDA >= max(1,N). !> ``` *AF* ``` !> AF is DOUBLE PRECISION array, dimension (LDAF,N) !> The block diagonal matrix D and the multipliers used to !> obtain the factor U or L as computed by DSYTRF. !> ``` *LDAF* ``` !> LDAF is INTEGER !> The leading dimension of the array AF. LDAF >= max(1,N). !> ``` *IPIV* ``` !> IPIV is INTEGER array, dimension (N) !> Details of the interchanges and the block structure of D !> as determined by DSYTRF. !> ``` *CMODE* ``` !> CMODE is INTEGER !> Determines op2(C) in the formula op(A) * op2(C) as follows: !> CMODE = 1 op2(C) = C !> CMODE = 0 op2(C) = I !> CMODE = -1 op2(C) = inv(C) !> ``` *C* ``` !> C is DOUBLE PRECISION array, dimension (N) !> The vector C in the formula op(A) * op2(C). !> ``` *INFO* ``` !> INFO is INTEGER !> = 0: Successful exit. !> i > 0: The ith argument is invalid. !> ``` *WORK* ``` !> WORK is DOUBLE PRECISION array, dimension (3*N). !> Workspace. !> ``` *IWORK* ``` !> IWORK is INTEGER array, dimension (N). !> Workspace. !> ``` **Author** Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Definition at line **145** of file **dla\_syrcond.f**. ### real function sla\_syrcond (character uplo, integer n, real, dimension( lda, \* ) a, integer lda, real, dimension( ldaf, \* ) af, integer ldaf, integer, dimension( \* ) ipiv, integer cmode, real, dimension( \* ) c, integer info, real, dimension( \* ) work, integer, dimension( \* ) iwork) **SLA\_SYRCOND** estimates the Skeel condition number for a symmetric indefinite matrix. **Purpose:** ``` !> !> SLA_SYRCOND estimates the Skeel condition number of op(A) * op2(C) !> where op2 is determined by CMODE as follows !> CMODE = 1 op2(C) = C !> CMODE = 0 op2(C) = I !> CMODE = -1 op2(C) = inv(C) !> The Skeel condition number cond(A) = norminf( |inv(A)||A| ) !> is computed by computing scaling factors R such that !> diag(R)*A*op2(C) is row equilibrated and computing the standard !> infinity-norm condition number. !> ``` **Parameters** *UPLO* ``` !> UPLO is CHARACTER*1 !> = 'U': Upper triangle of A is stored; !> = 'L': Lower triangle of A is stored. !> ``` *N* ``` !> N is INTEGER !> The number of linear equations, i.e., the order of the !> matrix A. N >= 0. !> ``` *A* ``` !> A is REAL array, dimension (LDA,N) !> On entry, the N-by-N matrix A. !> ``` *LDA* ``` !> LDA is INTEGER !> The leading dimension of the array A. LDA >= max(1,N). !> ``` *AF* ``` !> AF is REAL array, dimension (LDAF,N) !> The block diagonal matrix D and the multipliers used to !> obtain the factor U or L as computed by SSYTRF. !> ``` *LDAF* ``` !> LDAF is INTEGER !> The leading dimension of the array AF. LDAF >= max(1,N). !> ``` *IPIV* ``` !> IPIV is INTEGER array, dimension (N) !> Details of the interchanges and the block structure of D !> as determined by SSYTRF. !> ``` *CMODE* ``` !> CMODE is INTEGER !> Determines op2(C) in the formula op(A) * op2(C) as follows: !> CMODE = 1 op2(C) = C !> CMODE = 0 op2(C) = I !> CMODE = -1 op2(C) = inv(C) !> ``` *C* ``` !> C is REAL array, dimension (N) !> The vector C in the formula op(A) * op2(C). !> ``` *INFO* ``` !> INFO is INTEGER !> = 0: Successful exit. !> i > 0: The ith argument is invalid. !> ``` *WORK* ``` !> WORK is REAL array, dimension (3*N). !> Workspace. !> ``` *IWORK* ``` !> IWORK is INTEGER array, dimension (N). !> Workspace. !> ``` **Author** Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Definition at line **144** of file **sla\_syrcond.f**. ### double precision function zla\_hercond\_c (character uplo, integer n, complex\*16, dimension( lda, \* ) a, integer lda, complex\*16, dimension( ldaf, \* ) af, integer ldaf, integer, dimension( \* ) ipiv, double precision, dimension ( \* ) c, logical capply, integer info, complex\*16, dimension( \* ) work, double precision, dimension( \* ) rwork) **ZLA\_HERCOND\_C** computes the infinity norm condition number of op(A)\*inv(diag(c)) for Hermitian indefinite matrices. **Purpose:** ``` !> !> ZLA_HERCOND_C computes the infinity norm condition number of !> op(A) * inv(diag(C)) where C is a DOUBLE PRECISION vector. !> ``` **Parameters** *UPLO* ``` !> UPLO is CHARACTER*1 !> = 'U': Upper triangle of A is stored; !> = 'L': Lower triangle of A is stored. !> ``` *N* ``` !> N is INTEGER !> The number of linear equations, i.e., the order of the !> matrix A. N >= 0. !> ``` *A* ``` !> A is COMPLEX*16 array, dimension (LDA,N) !> On entry, the N-by-N matrix A !> ``` *LDA* ``` !> LDA is INTEGER !> The leading dimension of the array A. LDA >= max(1,N). !> ``` *AF* ``` !> AF is COMPLEX*16 array, dimension (LDAF,N) !> The block diagonal matrix D and the multipliers used to !> obtain the factor U or L as computed by ZHETRF. !> ``` *LDAF* ``` !> LDAF is INTEGER !> The leading dimension of the array AF. LDAF >= max(1,N). !> ``` *IPIV* ``` !> IPIV is INTEGER array, dimension (N) !> Details of the interchanges and the block structure of D !> as determined by CHETRF. !> ``` *C* ``` !> C is DOUBLE PRECISION array, dimension (N) !> The vector C in the formula op(A) * inv(diag(C)). !> ``` *CAPPLY* ``` !> CAPPLY is LOGICAL !> If .TRUE. then access the vector C in the formula above. !> ``` *INFO* ``` !> INFO is INTEGER !> = 0: Successful exit. !> i > 0: The ith argument is invalid. !> ``` *WORK* ``` !> WORK is COMPLEX*16 array, dimension (2*N). !> Workspace. !> ``` *RWORK* ``` !> RWORK is DOUBLE PRECISION array, dimension (N). !> Workspace. !> ``` **Author** Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Definition at line **137** of file **zla\_hercond\_c.f**. ### double precision function zla\_hercond\_x (character uplo, integer n, complex\*16, dimension( lda, \* ) a, integer lda, complex\*16, dimension( ldaf, \* ) af, integer ldaf, integer, dimension( \* ) ipiv, complex\*16, dimension( \* ) x, integer info, complex\*16, dimension( \* ) work, double precision, dimension( \* ) rwork) **ZLA\_HERCOND\_X** computes the infinity norm condition number of op(A)\*diag(x) for Hermitian indefinite matrices. **Purpose:** ``` !> !> ZLA_HERCOND_X computes the infinity norm condition number of !> op(A) * diag(X) where X is a COMPLEX*16 vector. !> ``` **Parameters** *UPLO* ``` !> UPLO is CHARACTER*1 !> = 'U': Upper triangle of A is stored; !> = 'L': Lower triangle of A is stored. !> ``` *N* ``` !> N is INTEGER !> The number of linear equations, i.e., the order of the !> matrix A. N >= 0. !> ``` *A* ``` !> A is COMPLEX*16 array, dimension (LDA,N) !> On entry, the N-by-N matrix A. !> ``` *LDA* ``` !> LDA is INTEGER !> The leading dimension of the array A. LDA >= max(1,N). !> ``` *AF* ``` !> AF is COMPLEX*16 array, dimension (LDAF,N) !> The block diagonal matrix D and the multipliers used to !> obtain the factor U or L as computed by ZHETRF. !> ``` *LDAF* ``` !> LDAF is INTEGER !> The leading dimension of the array AF. LDAF >= max(1,N). !> ``` *IPIV* ``` !> IPIV is INTEGER array, dimension (N) !> Details of the interchanges and the block structure of D !> as determined by CHETRF. !> ``` *X* ``` !> X is COMPLEX*16 array, dimension (N) !> The vector X in the formula op(A) * diag(X). !> ``` *INFO* ``` !> INFO is INTEGER !> = 0: Successful exit. !> i > 0: The ith argument is invalid. !> ``` *WORK* ``` !> WORK is COMPLEX*16 array, dimension (2*N). !> Workspace. !> ``` *RWORK* ``` !> RWORK is DOUBLE PRECISION array, dimension (N). !> Workspace. !> ``` **Author** Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Definition at line **130** of file **zla\_hercond\_x.f**. ### double precision function zla\_syrcond\_c (character uplo, integer n, complex\*16, dimension( lda, \* ) a, integer lda, complex\*16, dimension( ldaf, \* ) af, integer ldaf, integer, dimension( \* ) ipiv, double precision, dimension( \* ) c, logical capply, integer info, complex\*16, dimension( \* ) work, double precision, dimension( \* ) rwork) **ZLA\_SYRCOND\_C** computes the infinity norm condition number of op(A)\*inv(diag(c)) for symmetric indefinite matrices. **Purpose:** ``` !> !> ZLA_SYRCOND_C Computes the infinity norm condition number of !> op(A) * inv(diag(C)) where C is a DOUBLE PRECISION vector. !> ``` **Parameters** *UPLO* ``` !> UPLO is CHARACTER*1 !> = 'U': Upper triangle of A is stored; !> = 'L': Lower triangle of A is stored. !> ``` *N* ``` !> N is INTEGER !> The number of linear equations, i.e., the order of the !> matrix A. N >= 0. !> ``` *A* ``` !> A is COMPLEX*16 array, dimension (LDA,N) !> On entry, the N-by-N matrix A !> ``` *LDA* ``` !> LDA is INTEGER !> The leading dimension of the array A. LDA >= max(1,N). !> ``` *AF* ``` !> AF is COMPLEX*16 array, dimension (LDAF,N) !> The block diagonal matrix D and the multipliers used to !> obtain the factor U or L as computed by ZSYTRF. !> ``` *LDAF* ``` !> LDAF is INTEGER !> The leading dimension of the array AF. LDAF >= max(1,N). !> ``` *IPIV* ``` !> IPIV is INTEGER array, dimension (N) !> Details of the interchanges and the block structure of D !> as determined by ZSYTRF. !> ``` *C* ``` !> C is DOUBLE PRECISION array, dimension (N) !> The vector C in the formula op(A) * inv(diag(C)). !> ``` *CAPPLY* ``` !> CAPPLY is LOGICAL !> If .TRUE. then access the vector C in the formula above. !> ``` *INFO* ``` !> INFO is INTEGER !> = 0: Successful exit. !> i > 0: The ith argument is invalid. !> ``` *WORK* ``` !> WORK is COMPLEX*16 array, dimension (2*N). !> Workspace. !> ``` *RWORK* ``` !> RWORK is DOUBLE PRECISION array, dimension (N). !> Workspace. !> ``` **Author** Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Definition at line **137** of file **zla\_syrcond\_c.f**. ### double precision function zla\_syrcond\_x (character uplo, integer n, complex\*16, dimension( lda, \* ) a, integer lda, complex\*16, dimension( ldaf, \* ) af, integer ldaf, integer, dimension( \* ) ipiv, complex\*16, dimension( \* ) x, integer info, complex\*16, dimension( \* ) work, double precision, dimension( \* ) rwork) **ZLA\_SYRCOND\_X** computes the infinity norm condition number of op(A)\*diag(x) for symmetric indefinite matrices. **Purpose:** ``` !> !> ZLA_SYRCOND_X Computes the infinity norm condition number of !> op(A) * diag(X) where X is a COMPLEX*16 vector. !> ``` **Parameters** *UPLO* ``` !> UPLO is CHARACTER*1 !> = 'U': Upper triangle of A is stored; !> = 'L': Lower triangle of A is stored. !> ``` *N* ``` !> N is INTEGER !> The number of linear equations, i.e., the order of the !> matrix A. N >= 0. !> ``` *A* ``` !> A is COMPLEX*16 array, dimension (LDA,N) !> On entry, the N-by-N matrix A. !> ``` *LDA* ``` !> LDA is INTEGER !> The leading dimension of the array A. LDA >= max(1,N). !> ``` *AF* ``` !> AF is COMPLEX*16 array, dimension (LDAF,N) !> The block diagonal matrix D and the multipliers used to !> obtain the factor U or L as computed by ZSYTRF. !> ``` *LDAF* ``` !> LDAF is INTEGER !> The leading dimension of the array AF. LDAF >= max(1,N). !> ``` *IPIV* ``` !> IPIV is INTEGER array, dimension (N) !> Details of the interchanges and the block structure of D !> as determined by ZSYTRF. !> ``` *X* ``` !> X is COMPLEX*16 array, dimension (N) !> The vector X in the formula op(A) * diag(X). !> ``` *INFO* ``` !> INFO is INTEGER !> = 0: Successful exit. !> i > 0: The ith argument is invalid. !> ``` *WORK* ``` !> WORK is COMPLEX*16 array, dimension (2*N). !> Workspace. !> ``` *RWORK* ``` !> RWORK is DOUBLE PRECISION array, dimension (N). !> Workspace. !> ``` **Author** Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Definition at line **130** of file **zla\_syrcond\_x.f**. ## Author Generated automatically by Doxygen for LAPACK from the source code.