ztgexc
ztgexc - reorder the generalized Schur decomposition of a complex matrix pair (A,B), using an unitary equivalence transformation (A, B) := Q * (A, B) * Z', so that the diagonal block of (A, B) with row index IFST is moved to row ILST
SUBROUTINE ZTGEXC( WANTQ, WANTZ, N, A, LDA, B, LDB, Q, LDQ, Z, LDZ,
* IFST, ILST, INFO)
DOUBLE COMPLEX A(LDA,*), B(LDB,*), Q(LDQ,*), Z(LDZ,*)
INTEGER N, LDA, LDB, LDQ, LDZ, IFST, ILST, INFO
LOGICAL WANTQ, WANTZ
SUBROUTINE ZTGEXC_64( WANTQ, WANTZ, N, A, LDA, B, LDB, Q, LDQ, Z,
* LDZ, IFST, ILST, INFO)
DOUBLE COMPLEX A(LDA,*), B(LDB,*), Q(LDQ,*), Z(LDZ,*)
INTEGER*8 N, LDA, LDB, LDQ, LDZ, IFST, ILST, INFO
LOGICAL*8 WANTQ, WANTZ
SUBROUTINE TGEXC( WANTQ, WANTZ, [N], A, [LDA], B, [LDB], Q, [LDQ],
* Z, [LDZ], IFST, ILST, [INFO])
COMPLEX(8), DIMENSION(:,:) :: A, B, Q, Z
INTEGER :: N, LDA, LDB, LDQ, LDZ, IFST, ILST, INFO
LOGICAL :: WANTQ, WANTZ
SUBROUTINE TGEXC_64( WANTQ, WANTZ, [N], A, [LDA], B, [LDB], Q, [LDQ],
* Z, [LDZ], IFST, ILST, [INFO])
COMPLEX(8), DIMENSION(:,:) :: A, B, Q, Z
INTEGER(8) :: N, LDA, LDB, LDQ, LDZ, IFST, ILST, INFO
LOGICAL(8) :: WANTQ, WANTZ
#include <sunperf.h>
void ztgexc(logical wantq, logical wantz, int n, doublecomplex *a, int lda, doublecomplex *b, int ldb, doublecomplex *q, int ldq, doublecomplex *z, int ldz, int *ifst, int *ilst, int *info);
void ztgexc_64(logical wantq, logical wantz, long n, doublecomplex *a, long lda, doublecomplex *b, long ldb, doublecomplex *q, long ldq, doublecomplex *z, long ldz, long *ifst, long *ilst, long *info);
ztgexc reorders the generalized Schur decomposition of a complex
matrix pair (A,B), using an unitary equivalence transformation
(A, B) := Q * (A, B) * Z', so that the diagonal block of (A, B) with
row index IFST is moved to row ILST.
(A, B) must be in generalized Schur canonical form, that is, A and
B are both upper triangular.
Optionally, the matrices Q and Z of generalized Schur vectors are
updated.
Q(in) * A(in) * Z(in)' = Q(out) * A(out) * Z(out)'
Q(in) * B(in) * Z(in)' = Q(out) * B(out) * Z(out)'
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* WANTQ (input)
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.TRUE. : update the left transformation matrix Q;
.FALSE.: do not update Q.
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* WANTZ (input)
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.TRUE. : update the right transformation matrix Z;
.FALSE.: do not update Z.
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* N (input)
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The order of the matrices A and B. N >= 0.
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* A (input/output)
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On entry, the upper triangular matrix A in the pair (A, B).
On exit, the updated matrix A.
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* LDA (input)
-
The leading dimension of the array A. LDA >= max(1,N).
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* B (input/output)
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On entry, the upper triangular matrix B in the pair (A, B).
On exit, the updated matrix B.
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* LDB (input)
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The leading dimension of the array B. LDB >= max(1,N).
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* Q (input/output)
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On entry, if WANTQ = .TRUE., the unitary matrix Q.
On exit, the updated matrix Q.
If WANTQ = .FALSE., Q is not referenced.
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* LDQ (input)
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The leading dimension of the array Q. LDQ >= 1;
If WANTQ = .TRUE., LDQ >= N.
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* Z (input/output)
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On entry, if WANTZ = .TRUE., the unitary matrix Z.
On exit, the updated matrix Z.
If WANTZ = .FALSE., Z is not referenced.
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* LDZ (input)
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The leading dimension of the array Z. LDZ >= 1;
If WANTZ = .TRUE., LDZ >= N.
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* IFST (input/output)
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Specify the reordering of the diagonal blocks of (A, B).
The block with row index IFST is moved to row ILST, by a
sequence of swapping between adjacent blocks.
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* ILST (input/output)
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See the description of IFST.
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* INFO (output)
-