laqz4 - laqz4: step in ggev3, gges3

Generated automatically by Doxygen for LAPACK from the source code. Version 3.12.0 Thu Aug 7 2025 17:26:25 laqz4(3)

subroutinedlaqz4(logical,intent(in)ilschur,logical,intent(in)ilq,logical,intent(in)ilz,integer,intent(in)n,integer,intent(in)ilo,integer,intent(in)ihi,integer,intent(in)nshifts,integer,intent(in)nblock_desired,doubleprecision,dimension(*),intent(inout)sr,doubleprecision,dimension(*),intent(inout)si,doubleprecision,dimension(*),intent(inout)ss,doubleprecision,dimension(lda,*),intent(inout)a,integer,intent(in)lda,doubleprecision,dimension(ldb,*),intent(inout)b,integer,intent(in)ldb,doubleprecision,dimension(ldq,*),intent(inout)q,integer,intent(in)ldq,doubleprecision,dimension(ldz,*),intent(inout)z,integer,intent(in)ldz,doubleprecision,dimension(ldqc,*),intent(inout)qc,integer,intent(in)ldqc,doubleprecision,dimension(ldzc,*),intent(inout)zc,integer,intent(in)ldzc,doubleprecision,dimension(*),intent(inout)work,integer,intent(in)lwork,integer,intent(out)info)DLAQZ4Purpose: DLAQZ4 Executes a single multishift QZ sweep ParametersILSCHUR ILSCHUR is LOGICAL Determines whether or not to update the full Schur form ILQ ILQ is LOGICAL Determines whether or not to update the matrix Q ILZ ILZ is LOGICAL Determines whether or not to update the matrix Z N N is INTEGER The order of the matrices A, B, Q, and Z. N >= 0. ILO ILO is INTEGER IHI IHI is INTEGER NSHIFTS NSHIFTS is INTEGER The desired number of shifts to use NBLOCK_DESIRED NBLOCK_DESIRED is INTEGER The desired size of the computational windows SR SR is DOUBLE PRECISION array. SR contains the real parts of the shifts to use. SI SI is DOUBLE PRECISION array. SI contains the imaginary parts of the shifts to use. SS SS is DOUBLE PRECISION array. SS contains the scale of the shifts to use. A A is DOUBLE PRECISION array, dimension (LDA, N) LDA LDA is INTEGER The leading dimension of the array A. LDA >= max( 1, N ). B B is DOUBLE PRECISION array, dimension (LDB, N) LDB LDB is INTEGER The leading dimension of the array B. LDB >= max( 1, N ). Q Q is DOUBLE PRECISION array, dimension (LDQ, N) LDQ LDQ is INTEGER Z Z is DOUBLE PRECISION array, dimension (LDZ, N) LDZ LDZ is INTEGER QC QC is DOUBLE PRECISION array, dimension (LDQC, NBLOCK_DESIRED) LDQC LDQC is INTEGER ZC ZC is DOUBLE PRECISION array, dimension (LDZC, NBLOCK_DESIRED) LDZC LDZ is INTEGER WORK WORK is DOUBLE PRECISION array, dimension (MAX(1,LWORK)) On exit, if INFO >= 0, WORK(1) returns the optimal LWORK. LWORK LWORK is INTEGER The dimension of the array WORK. LWORK >= max(1,N). If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA. INFO INFO is INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value Author Thijs Steel, KU Leuven Date May 2020 subroutineslaqz4(logical,intent(in)ilschur,logical,intent(in)ilq,logical,intent(in)ilz,integer,intent(in)n,integer,intent(in)ilo,integer,intent(in)ihi,integer,intent(in)nshifts,integer,intent(in)nblock_desired,real,dimension(*),intent(inout)sr,real,dimension(*),intent(inout)si,real,dimension(*),intent(inout)ss,real,dimension(lda,*),intent(inout)a,integer,intent(in)lda,real,dimension(ldb,*),intent(inout)b,integer,intent(in)ldb,real,dimension(ldq,*),intent(inout)q,integer,intent(in)ldq,real,dimension(ldz,*),intent(inout)z,integer,intent(in)ldz,real,dimension(ldqc,*),intent(inout)qc,integer,intent(in)ldqc,real,dimension(ldzc,*),intent(inout)zc,integer,intent(in)ldzc,real,dimension(*),intent(inout)work,integer,intent(in)lwork,integer,intent(out)info)SLAQZ4Purpose: SLAQZ4 Executes a single multishift QZ sweep ParametersILSCHUR ILSCHUR is LOGICAL Determines whether or not to update the full Schur form ILQ ILQ is LOGICAL Determines whether or not to update the matrix Q ILZ ILZ is LOGICAL Determines whether or not to update the matrix Z N N is INTEGER The order of the matrices A, B, Q, and Z. N >= 0. ILO ILO is INTEGER IHI IHI is INTEGER NSHIFTS NSHIFTS is INTEGER The desired number of shifts to use NBLOCK_DESIRED NBLOCK_DESIRED is INTEGER The desired size of the computational windows SR SR is REAL array. SR contains the real parts of the shifts to use. SI SI is REAL array. SI contains the imaginary parts of the shifts to use. SS SS is REAL array. SS contains the scale of the shifts to use. A A is REAL array, dimension (LDA, N) LDA LDA is INTEGER The leading dimension of the array A. LDA >= max( 1, N ). B B is REAL array, dimension (LDB, N) LDB LDB is INTEGER The leading dimension of the array B. LDB >= max( 1, N ). Q Q is REAL array, dimension (LDQ, N) LDQ LDQ is INTEGER Z Z is REAL array, dimension (LDZ, N) LDZ LDZ is INTEGER QC QC is REAL array, dimension (LDQC, NBLOCK_DESIRED) LDQC LDQC is INTEGER ZC ZC is REAL array, dimension (LDZC, NBLOCK_DESIRED) LDZC LDZ is INTEGER WORK WORK is REAL array, dimension (MAX(1,LWORK)) On exit, if INFO >= 0, WORK(1) returns the optimal LWORK. LWORK LWORK is INTEGER The dimension of the array WORK. LWORK >= max(1,N). If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA. INFO INFO is INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value Author Thijs Steel, KU Leuven Date May 2020

laqz4 - laqz4: step in ggev3, gges3

Functions subroutine dlaqz4 (ilschur, ilq, ilz, n, ilo, ihi, nshifts, nblock_desired, sr, si, ss, a, lda, b, ldb, q, ldq, z, ldz, qc, ldqc, zc, ldzc, work, lwork, info) DLAQZ4 subroutine slaqz4 (ilschur, ilq, ilz, n, ilo, ihi, nshifts, nblock_desired, sr, si, ss, a, lda, b, ldb, q, ldq, z, ldz, qc, ldqc, zc, ldzc, work, lwork, info) SLAQZ4