hecon_3(3)
๐ธ hecon_3(3) โ {he,sy}con_3: condition number estimate ๐ธ
okay bestie, buckle up ๐ this is hecon_3(3) from the Library Functions Manual, and it's literally the glow-up your linear algebra era has been waiting for. Six routines, all doing the same iconic job in different flavors: they estimate the reciprocal of the condition number. Periodt.
โจ SYNOPSIS โจ
Six subroutines, all serving the same vibe with different dtypes. Obsessed. ๐ซถ
Functions
subroutine checon_3 (uplo, n, a, lda, e, ipiv, anorm, rcond, work, info)
CHECON_3
subroutine csycon_3 (uplo, n, a, lda, e, ipiv, anorm, rcond, work, info)
CSYCON_3
subroutine dsycon_3 (uplo, n, a, lda, e, ipiv, anorm, rcond, work,
iwork, info)
DSYCON_3
subroutine ssycon_3 (uplo, n, a, lda, e, ipiv, anorm, rcond, work,
iwork, info)
SSYCON_3
subroutine zhecon_3 (uplo, n, a, lda, e, ipiv, anorm, rcond, work, info)
ZHECON_3
subroutine zsycon_3 (uplo, n, a, lda, e, ipiv, anorm, rcond, work, info)
ZSYCON_3
Spot the pattern? The complex ones (checon_3, csycon_3, zhecon_3, zsycon_3) don't need iwork. The real ones (dsycon_3, ssycon_3) do. That's the whole tea. ๐ต
๐ Detailed Description ๐
Not me about to dump six function docs on you โ but respectfully, that's exactly what's happening. Each one gets its own subsection below, Function Documentation style, with the full signature, the Purpose block, every single parameter, the Authors, the Contributors, and where the source lives. No skipping. No cap. ๐ฅ
๐ Function Documentation ๐
๐ checon_3 โ CHECON_3 ๐
The full signature, character for character:
subroutine checon_3 (character uplo, integer n, complex, dimension( lda, * )
a, integer lda, complex, dimension( * ) e, integer, dimension( * ) ipiv,
real anorm, real rcond, complex, dimension( * ) work, integer info)
โญ Purpose
So CHECON_3 estimates the reciprocal of the condition number โ in the 1-norm โ of a complex Hermitian matrix A, using the factorization computed by CHETRF_RK or CHETRF_BK:
A = P*U*D*(U**H)*(P**T) or A = P*L*D*(L**H)*(P**T),
where, in the most chill way possible:
U(orL) is a unit upper (or lower) triangular matrixU**H(orL**H) is the conjugate ofU(orL)Pis a permutation matrixP**Tis the transpose ofPDis Hermitian and block diagonal with 1-by-1 and 2-by-2 diagonal blocks
An estimate is obtained for norm(inv(A)), and then the reciprocal of the condition number is computed as:
RCOND = 1 / (ANORM * norm(inv(A))).
This routine uses the BLAS3 solver CHETRS_3. Slay. โจ
๐ Parameters
UPLOโUPLO is CHARACTER*1. Specifies whether the details of the factorization are stored as an upper or lower triangular matrix:= 'U':Upper triangular, form isA = P*U*D*(U**H)*(P**T);= 'L':Lower triangular, form isA = P*L*D*(L**H)*(P**T).
NโN is INTEGER. The order of the matrixA.N >= 0.AโA is COMPLEX array, dimension (LDA,N). Holds the diagonal of the block diagonal matrixDand the factorsUorLas computed byCHETRF_RKandCHETRF_BK:- ONLY the diagonal elements of the Hermitian block diagonal matrix
Dgo on the diagonal ofA, i.e.D(k,k) = A(k,k);โ and the superdiagonal (or subdiagonal) elements ofDshould be provided on entry in arrayE. - If
UPLO = 'U': factorUlives in the superdiagonal part ofA. IfUPLO = 'L': factorLlives in the subdiagonal part ofA.
- ONLY the diagonal elements of the Hermitian block diagonal matrix
LDAโLDA is INTEGER. The leading dimension of the arrayA.LDA >= max(1,N).EโE is COMPLEX array, dimension (N). On entry, contains the superdiagonal (or subdiagonal) elements of the Hermitian block diagonal matrixDwith 1-by-1 or 2-by-2 diagonal blocks, where:- If
UPLO = 'U':E(i) = D(i-1,i),i=2:N, E(1)not referenced; - If
UPLO = 'L':E(i) = D(i+1,i),i=1:N-1, E(N)not referenced.
- If
NOTE: for a 1-by-1 diagonal blockD(k), where1 <= k <= N, the elementE(k)is not referenced in both theUPLO = 'U'andUPLO = 'L'cases. ๐
IPIVโIPIV is INTEGER array, dimension (N). All the details of the interchanges and the block structure ofD, as determined byCHETRF_RKorCHETRF_BK.ANORMโANORM is REAL. The 1-norm of the original matrixA.RCONDโRCOND is REAL. The reciprocal of the condition number of the matrixA, computed asRCOND = 1/(ANORM * AINVNM), whereAINVNMis an estimate of the 1-norm ofinv(A)computed in this routine.WORKโWORK is COMPLEX array, dimension (2*N).INFOโINFO is INTEGER:= 0:successful exit ๐< 0:ifINFO = -i, thei-th argument had an illegal value ๐
๐ Author
- Univ. of Tennessee
- Univ. of California Berkeley
- Univ. of Colorado Denver
- NAG Ltd.
๐ฆ Contributors
- June 2017, Igor Kozachenko, Computer Science Division, University of California, Berkeley
- September 2007, Sven Hammarling, Nicholas J. Higham, Craig Lucas, School of Mathematics, University of Manchester
Definition at line 164 of file checon_3.f.
๐ฉท csycon_3 โ CSYCON_3 ๐ฉท
The full signature, verbatim:
subroutine csycon_3 (character uplo, integer n, complex, dimension( lda, * )
a, integer lda, complex, dimension( * ) e, integer, dimension( * ) ipiv,
real anorm, real rcond, complex, dimension( * ) work, integer info)
โญ Purpose
CSYCON_3 estimates the reciprocal of the condition number โ again, in the 1-norm โ of a complex symmetric matrix A, using the factorization computed by CSYTRF_RK or CSYTRF_BK:
A = P*U*D*(U**T)*(P**T) or A = P*L*D*(L**T)*(P**T),
where:
U(orL) is a unit upper (or lower) triangular matrixU**T(orL**T) is the transpose ofU(orL)Pis a permutation matrixP**Tis the transpose ofPDis symmetric and block diagonal with 1-by-1 and 2-by-2 diagonal blocks
An estimate is obtained for norm(inv(A)), and the reciprocal of the condition number is computed as:
RCOND = 1 / (ANORM * norm(inv(A))).
This routine uses the BLAS3 solver CSYTRS_3. Main character energy, honestly. ๐
๐ Parameters
UPLOโUPLO is CHARACTER*1. Specifies whether the details of the factorization are stored as an upper or lower triangular matrix:= 'U':Upper triangular, form isA = P*U*D*(U**T)*(P**T);= 'L':Lower triangular, form isA = P*L*D*(L**T)*(P**T).
NโN is INTEGER. The order of the matrixA.N >= 0.AโA is COMPLEX array, dimension (LDA,N). Holds the diagonal of the block diagonal matrixDand the factorsUorLas computed byCSYTRF_RKandCSYTRF_BK:- ONLY the diagonal elements of the symmetric block diagonal matrix
Don the diagonal ofA, i.e.D(k,k) = A(k,k);โ the superdiagonal (or subdiagonal) elements ofDshould be provided on entry in arrayE. - If
UPLO = 'U': factorUin the superdiagonal part ofA. IfUPLO = 'L': factorLin the subdiagonal part ofA.
- ONLY the diagonal elements of the symmetric block diagonal matrix
LDAโLDA is INTEGER. The leading dimension of the arrayA.LDA >= max(1,N).EโE is COMPLEX array, dimension (N). On entry, contains the superdiagonal (or subdiagonal) elements of the symmetric block diagonal matrixDwith 1-by-1 or 2-by-2 diagonal blocks, where:- If
UPLO = 'U':E(i) = D(i-1,i),i=2:N, E(1)not referenced; - If
UPLO = 'L':E(i) = D(i+1,i),i=1:N-1, E(N)not referenced.
- If
NOTE: for a 1-by-1 diagonal blockD(k), where1 <= k <= N, the elementE(k)is not referenced in both theUPLO = 'U'andUPLO = 'L'cases. ๐
IPIVโIPIV is INTEGER array, dimension (N). Details of the interchanges and the block structure ofD, as determined byCSYTRF_RKorCSYTRF_BK.ANORMโANORM is REAL. The 1-norm of the original matrixA.RCONDโRCOND is REAL. The reciprocal of the condition number of the matrixA, computed asRCOND = 1/(ANORM * AINVNM), whereAINVNMis an estimate of the 1-norm ofinv(A)computed in this routine.WORKโWORK is COMPLEX array, dimension (2*N).INFOโINFO is INTEGER:= 0:successful exit ๐< 0:ifINFO = -i, thei-th argument had an illegal value ๐
๐ Author
- Univ. of Tennessee
- Univ. of California Berkeley
- Univ. of Colorado Denver
- NAG Ltd.
๐ฆ Contributors
- June 2017, Igor Kozachenko, Computer Science Division, University of California, Berkeley
- September 2007, Sven Hammarling, Nicholas J. Higham, Craig Lucas, School of Mathematics, University of Manchester
Definition at line 164 of file csycon_3.f.
๐ dsycon_3 โ DSYCON_3 ๐
The full signature, exactly as written (yes, it wraps, that's the source's business not mine):
subroutine dsycon_3 (character uplo, integer n, double precision, dimension(
lda, * ) a, integer lda, double precision, dimension( * ) e, integer,
dimension( * ) ipiv, double precision anorm, double precision rcond,
double precision, dimension( * ) work, integer, dimension( * ) iwork,
integer info)
โญ Purpose
DSYCON_3 estimates the reciprocal of the condition number โ 1-norm girlie โ of a real symmetric matrix A, using the factorization computed by DSYTRF_RK or DSYTRF_BK:
A = P*U*D*(U**T)*(P**T) or A = P*L*D*(L**T)*(P**T),
where:
U(orL) is a unit upper (or lower) triangular matrixU**T(orL**T) is the transpose ofU(orL)Pis a permutation matrixP**Tis the transpose ofPDis symmetric and block diagonal with 1-by-1 and 2-by-2 diagonal blocks
An estimate is obtained for norm(inv(A)), and the reciprocal of the condition number is computed as:
RCOND = 1 / (ANORM * norm(inv(A))).
This routine uses the BLAS3 solver DSYTRS_3. ๐ซถ
๐ Parameters
UPLOโ
okay bestie that's where the page cuts off mid-parameter-list ๐ the UPLO rundown for dsycon_3 (and everything after it โ the rest of dsycon_3, plus ssycon_3, zhecon_3, and zsycon_3) is coming in part 2. don't go anywhere, the lore continues ๐งโโ๏ธ๐ธ
UPLOโCHARACTER*1. Tells you whether the factorization details are stored as an upper or lower triangular matrix, bestie:= 'U': upper triangular, form isA = P*U*D*(U**T)*(P**T);= 'L': lower triangular, form isA = P*L*D*(L**T)*(P**T). ๐NโINTEGER. The order of the matrixA.N >= 0. Simple as that, no cap. โจAโDOUBLE PRECISION array, dimension (LDA,N). This is lowkey the main character: it holds the diagonal of the block diagonal matrixDand the factorsUorLas computed byDSYTRF_RKandDSYTRF_BK:- a) ONLY diagonal elements of the symmetric block diagonal matrix
Don the diagonal ofA, i.e.D(k,k) = A(k,k); (superdiagonal (or subdiagonal) elements ofDshould be provided on entry in arrayE), and - b) If
UPLO = 'U': factorUin the superdiagonal part ofA. IfUPLO = 'L': factorLin the subdiagonal part ofA. ๐ซถ
- a) ONLY diagonal elements of the symmetric block diagonal matrix
LDAโINTEGER. The leading dimension of the arrayA.LDA >= max(1,N). Respect the leading dimension, fr fr. ๐EโDOUBLE PRECISION array, dimension (N). On entry, contains the superdiagonal (or subdiagonal) elements of the symmetric block diagonal matrixDwith 1-by-1 or 2-by-2 diagonal blocks, where IfUPLO = 'U':E(i) = D(i-1,i),i=2:N,E(1)not referenced; IfUPLO = 'L':E(i) = D(i+1,i),i=1:N-1,E(N)not referenced. ๐ธ
NOTE: For 1-by-1 diagonal blockD(k), where1 <= k <= N, the elementE(k)is not referenced in bothUPLO = 'U'orUPLO = 'L'cases. Not me checkingE(k)when it literally says โnot referencedโ ๐
IPIVโINTEGER array, dimension (N). Details of the interchanges and the block structure ofDas determined byDSYTRF_RKorDSYTRF_BK. Iconic pivot behavior. ๐ANORMโDOUBLE PRECISION. The 1-norm of the original matrixA. Thatโs the vibe check for the original matrix. ๐ฅRCONDโDOUBLE PRECISION. The reciprocal of the condition number of the matrixA, computed asRCOND = 1/(ANORM * AINVNM), whereAINVNMis an estimate of the 1-norm ofinv(A)computed in this routine. Itโs giving โhow invertible are we reallyโ energy. ๐ฆWORKโDOUBLE PRECISION array, dimension (2*N). Workspace, bestie. Let it cook. ๐IWORKโINTEGER array, dimension (N). Integer workspace. Slay. โจINFOโINTEGER. Status tea:= 0: successful exit;< 0: ifINFO = -i, the i-th argument had an illegal value. ๐จ
๐ Author
- Univ. of Tennessee
- Univ. of California Berkeley
- Univ. of Colorado Denver
- NAG Ltd.
Contributors:
- June 2017, Igor Kozachenko, Computer Science Division, University of California, Berkeley
- September 2007, Sven Hammarling, Nicholas J. Higham, Craig Lucas, School of Mathematics, University of Manchester
Definition at line 169 of file dsycon_3.f.
๐ธ subroutine ssycon_3 ๐ธ
subroutine ssycon_3 (character uplo, integer n, real, dimension( lda, * ) a,
integer lda, real, dimension( * ) e, integer, dimension( * ) ipiv, real
anorm, real rcond, real, dimension( * ) work, integer, dimension( * )
iwork, integer info)
SSYCON_3
๐ฏ Purpose
SSYCON_3 estimates the reciprocal of the condition number (in the 1-norm) of a real symmetric matrix A using the factorization computed by DSYTRF_RK or DSYTRF_BK:
A = P*U*D*(U**T)*(P**T) or A = P*L*D*(L**T)*(P**T),
where U (or L) is unit upper (or lower) triangular matrix, U**T (or L**T) is the transpose of U (or L), P is a permutation matrix, P**T is the transpose of P, and D is symmetric and block diagonal with 1-by-1 and 2-by-2 diagonal blocks.
An estimate is obtained for norm(inv(A)), and the reciprocal of the condition number is computed as RCOND = 1 / (ANORM * norm(inv(A))). This routine uses BLAS3 solver SSYTRS_3. Obsessed with a BLAS3 solver moment, honestly. ๐ฅ
๐งฎ Parameters
UPLOโCHARACTER*1. Specifies whether the details of the factorization are stored as an upper or lower triangular matrix:= 'U': Upper triangular, form isA = P*U*D*(U**T)*(P**T);= 'L': Lower triangular, form isA = P*L*D*(L**T)*(P**T). ๐NโINTEGER. The order of the matrixA.N >= 0. โจAโREAL array, dimension (LDA,N). Diagonal of the block diagonal matrixDand factorsUorLas computed bySSYTRF_RKandSSYTRF_BK:- a) ONLY diagonal elements of the symmetric block diagonal matrix
Don the diagonal ofA, i.e.D(k,k) = A(k,k); (superdiagonal (or subdiagonal) elements ofDshould be provided on entry in arrayE), and - b) If
UPLO = 'U': factorUin the superdiagonal part ofA. IfUPLO = 'L': factorLin the subdiagonal part ofA. ๐ซถ
- a) ONLY diagonal elements of the symmetric block diagonal matrix
LDAโINTEGER. The leading dimension of the arrayA.LDA >= max(1,N). ๐EโREAL array, dimension (N). On entry, contains the superdiagonal (or subdiagonal) elements of the symmetric block diagonal matrixDwith 1-by-1 or 2-by-2 diagonal blocks, where IfUPLO = 'U':E(i) = D(i-1,i),i=2:N,E(1)not referenced; IfUPLO = 'L':E(i) = D(i+1,i),i=1:N-1,E(N)not referenced. ๐ธ
NOTE: For 1-by-1 diagonal blockD(k), where1 <= k <= N, the elementE(k)is not referenced in bothUPLO = 'U'orUPLO = 'L'cases. The way this note keeps showing up ๐ญ
IPIVโINTEGER array, dimension (N). Details of the interchanges and the block structure ofDas determined bySSYTRF_RKorSSYTRF_BK. ๐ANORMโREAL. The 1-norm of the original matrixA. ๐ฅRCONDโREAL. The reciprocal of the condition number of the matrixA, computed asRCOND = 1/(ANORM * AINVNM), whereAINVNMis an estimate of the 1-norm ofinv(A)computed in this routine. ๐ฆWORKโREAL array, dimension (2*N). Workspace, periodt. ๐IWORKโINTEGER array, dimension (N). Integer workspace. โจINFOโINTEGER.= 0: successful exit;< 0: ifINFO = -i, the i-th argument had an illegal value. ๐จ
๐ Author
- Univ. of Tennessee
- Univ. of California Berkeley
- Univ. of Colorado Denver
- NAG Ltd.
Contributors:
- June 2017, Igor Kozachenko, Computer Science Division, University of California, Berkeley
- September 2007, Sven Hammarling, Nicholas J. Higham, Craig Lucas, School of Mathematics, University of Manchester
Definition at line 169 of file ssycon_3.f.
๐ฆ subroutine zhecon_3 ๐ฆ
subroutine zhecon_3 (character uplo, integer n, complex*16, dimension( lda,
* ) a, integer lda, complex*16, dimension( * ) e, integer, dimension( *
) ipiv, double precision anorm, double precision rcond, complex*16,
dimension( * ) work, integer info)
ZHECON_3
๐ฏ Purpose
ZHECON_3 estimates the reciprocal of the condition number (in the 1-norm) of a complex Hermitian matrix A using the factorization computed by ZHETRF_RK or ZHETRF_BK:
A = P*U*D*(U**H)*(P**T) or A = P*L*D*(L**H)*(P**T),
where U (or L) is unit upper (or lower) triangular matrix, U**H (or L**H) is the conjugate of U (or L), P is a permutation matrix, P**T is the transpose of P, and D is Hermitian and block diagonal with 1-by-1 and 2-by-2 diagonal blocks.
An estimate is obtained for norm(inv(A)), and the reciprocal of the condition number is computed as RCOND = 1 / (ANORM * norm(inv(A))). This routine uses BLAS3 solver ZHETRS_3. Hermitian main character energy, literally. ๐
๐งฎ Parameters
UPLOโCHARACTER*1. Specifies whether the details of the factorization are stored as an upper or lower triangular matrix:= 'U': Upper triangular, form isA = P*U*D*(U**H)*(P**T);= 'L': Lower triangular, form isA = P*L*D*(L**H)*(P**T). ๐NโINTEGER. The order of the matrixA.N >= 0. โจAโCOMPLEX*16 array, dimension (LDA,N). Diagonal of the block diagonal matrixDand factorsUorLas computed byZHETRF_RKandZHETRF_BK:- a) ONLY diagonal elements of the Hermitian block diagonal matrix
Don the diagonal ofA, i.e.D(k,k) = A(k,k); (superdiagonal (or subdiagonal) elements ofDshould be provided on entry in arrayE), and - b) If
UPLO = 'U': factorUin the superdiagonal part ofA. IfUPLO = 'L': factorLin the subdiagonal part ofA. ๐ซถ
- a) ONLY diagonal elements of the Hermitian block diagonal matrix
LDAโINTEGER. The leading dimension of the arrayA.LDA >= max(1,N). ๐EโCOMPLEX*16 array, dimension (N). On entry, contains the superdiagonal (or subdiagonal) elements of the Hermitian block diagonal matrixDwith 1-by-1 or 2-by-2 diagonal blocks, where IfUPLO = 'U':E(i) = D(i-1,i),i=2:N,E(1)not referenced; IfUPLO = 'L':E(i) = D(i+1,i),i=1:N-1,E(N)not referenced. ๐ธ
NOTE: For 1-by-1 diagonal blockD(k), where1 <= k <= N, the elementE(k)is not referenced in bothUPLO = 'U'orUPLO = 'L'cases. This note is literally everywhere and I respect it ๐
IPIVIPIVโINTEGERarray, dimension(N). Details of the interchanges and the block structure of D as determined byZHETRF_RKorZHETRF_BK. ๐ซถANORMโDOUBLE PRECISION. The 1-norm of the original matrix A. ๐RCONDโDOUBLE PRECISION. The reciprocal of the condition number of the matrix A, computed asRCOND = 1/(ANORM * AINVNM), whereAINVNMis an estimate of the 1-norm ofinv(A)computed in this routine. ๐WORKโCOMPLEX*16array, dimension(2*N). โจINFOโINTEGER= 0: successful exit< 0: ifINFO = -i, the i-th argument had an illegal value
Author
- Univ. of Tennessee
- Univ. of California Berkeley
- Univ. of Colorado Denver
- NAG Ltd.
Contributors:
- June 2017, Igor Kozachenko, Computer Science Division, University of California, Berkeley
- September 2007, Sven Hammarling, Nicholas J. Higham, Craig Lucas, School of Mathematics, University of Manchester
Definition at line 164 of file zhecon_3.f.
zsycon_3 ๐
subroutine zsycon_3 (character uplo, integer n, complex*16, dimension( lda,
* ) a, integer lda, complex*16, dimension( * ) e, integer, dimension( *
) ipiv, double precision anorm, double precision rcond, complex*16,
dimension( * ) work, integer info)
ZSYCON_3
Purpose:
Okay bestie, hereโs the whole vibe: ZSYCON_3 estimates the reciprocal of the condition number (in the 1-norm) of a complex symmetric matrix A using the factorization computed by ZSYTRF_RK or ZSYTRF_BK:
A = P*U*D*(U**T)*(P**T) or A = P*L*D*(L**T)*(P**T),
where U (or L) is unit upper (or lower) triangular matrix, U**T (or L**T) is the transpose of U (or L), P is a permutation matrix, P**T is the transpose of P, and D is symmetric and block diagonal with 1-by-1 and 2-by-2 diagonal blocks. ๐ฆ
An estimate is obtained for norm(inv(A)), and the reciprocal of the condition number is computed as RCOND = 1 / (ANORM * norm(inv(A))). This routine uses BLAS3 solver ZSYTRS_3. ๐
Parameters
UPLOโCHARACTER*1. Specifies whether the details of the factorization are stored as an upper or lower triangular matrix:= 'U': Upper triangular, form isA = P*U*D*(U**T)*(P**T);= 'L': Lower triangular, form isA = P*L*D*(L**T)*(P**T).
NโINTEGER. The order of the matrix A.N >= 0. ๐ธAโCOMPLEX*16array, dimension(LDA,N). Diagonal of the block diagonal matrix D and factors U or L as computed byZSYTRF_RKandZSYTRF_BK:- a) ONLY diagonal elements of the symmetric block diagonal matrix D on the diagonal of A, i.e.
D(k,k) = A(k,k); (superdiagonal (or subdiagonal) elements of D should be provided on entry in array E), and - b) If
UPLO = 'U': factor U in the superdiagonal part of A. IfUPLO = 'L': factor L in the subdiagonal part of A.
- a) ONLY diagonal elements of the symmetric block diagonal matrix D on the diagonal of A, i.e.
LDAโINTEGER. The leading dimension of the array A.LDA >= max(1,N). ๐EโCOMPLEX*16array, dimension(N). On entry, contains the superdiagonal (or subdiagonal) elements of the symmetric block diagonal matrix D with 1-by-1 or 2-by-2 diagonal blocks, where- If
UPLO = 'U':E(i) = D(i-1,i),i=2:N,E(1)not referenced; - If
UPLO = 'L':E(i) = D(i+1,i),i=1:N-1,E(N)not referenced.
- If
NOTE: For 1-by-1 diagonal block D(k), where 1 <= k <= N, the element E(k) is not referenced in both UPLO = 'U' or UPLO = 'L' cases. ๐ญ
IPIVโINTEGERarray, dimension(N). Details of the interchanges and the block structure of D as determined byZSYTRF_RKorZSYTRF_BK. ๐ซถANORMโDOUBLE PRECISION. The 1-norm of the original matrix A. ๐RCONDโDOUBLE PRECISION. The reciprocal of the condition number of the matrix A, computed asRCOND = 1/(ANORM * AINVNM), whereAINVNMis an estimate of the 1-norm ofinv(A)computed in this routine. ๐WORKโCOMPLEX*16array, dimension(2*N). โจINFOโINTEGER= 0: successful exit< 0: ifINFO = -i, the i-th argument had an illegal value
Author
- Univ. of Tennessee
- Univ. of California Berkeley
- Univ. of Colorado Denver
- NAG Ltd.
Contributors:
- June 2017, Igor Kozachenko, Computer Science Division, University of California, Berkeley
- September 2007, Sven Hammarling, Nicholas J. Higham, Craig Lucas, School of Mathematics, University of Manchester
Definition at line 164 of file zsycon_3.f.
Author
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