.TH "SRC/zungtsqr.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*-
.ad l
.nh
.SH NAME
SRC/zungtsqr.f
.SH SYNOPSIS
.br
.PP
.SS "Functions/Subroutines"

.in +1c
.ti -1c
.RI "subroutine \fBzungtsqr\fP (m, n, mb, nb, a, lda, t, ldt, work, lwork, info)"
.br
.RI "\fBZUNGTSQR\fP "
.in -1c
.SH "Function/Subroutine Documentation"
.PP 
.SS "subroutine zungtsqr (integer m, integer n, integer mb, integer nb, complex*16, dimension( lda, * ) a, integer lda, complex*16, dimension( ldt, * ) t, integer ldt, complex*16, dimension( * ) work, integer lwork, integer info)"

.PP
\fBZUNGTSQR\fP  
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\fBPurpose:\fP
.RS 4

.PP
.nf
!>
!> ZUNGTSQR generates an M-by-N complex matrix Q_out with orthonormal
!> columns, which are the first N columns of a product of comlpex unitary
!> matrices of order M which are returned by ZLATSQR
!>
!>      Q_out = first_N_columns_of( Q(1)_in * Q(2)_in * \&.\&.\&. * Q(k)_in )\&.
!>
!> See the documentation for ZLATSQR\&.
!> 
.fi
.PP
 
.RE
.PP
\fBParameters\fP
.RS 4
\fIM\fP 
.PP
.nf
!>          M is INTEGER
!>          The number of rows of the matrix A\&.  M >= 0\&.
!> 
.fi
.PP
.br
\fIN\fP 
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.nf
!>          N is INTEGER
!>          The number of columns of the matrix A\&. M >= N >= 0\&.
!> 
.fi
.PP
.br
\fIMB\fP 
.PP
.nf
!>          MB is INTEGER
!>          The row block size used by ZLATSQR to return
!>          arrays A and T\&. MB > N\&.
!>          (Note that if MB > M, then M is used instead of MB
!>          as the row block size)\&.
!> 
.fi
.PP
.br
\fINB\fP 
.PP
.nf
!>          NB is INTEGER
!>          The column block size used by ZLATSQR to return
!>          arrays A and T\&. NB >= 1\&.
!>          (Note that if NB > N, then N is used instead of NB
!>          as the column block size)\&.
!> 
.fi
.PP
.br
\fIA\fP 
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.nf
!>          A is COMPLEX*16 array, dimension (LDA,N)
!>
!>          On entry:
!>
!>             The elements on and above the diagonal are not accessed\&.
!>             The elements below the diagonal represent the unit
!>             lower-trapezoidal blocked matrix V computed by ZLATSQR
!>             that defines the input matrices Q_in(k) (ones on the
!>             diagonal are not stored) (same format as the output A
!>             below the diagonal in ZLATSQR)\&.
!>
!>          On exit:
!>
!>             The array A contains an M-by-N orthonormal matrix Q_out,
!>             i\&.e the columns of A are orthogonal unit vectors\&.
!> 
.fi
.PP
.br
\fILDA\fP 
.PP
.nf
!>          LDA is INTEGER
!>          The leading dimension of the array A\&.  LDA >= max(1,M)\&.
!> 
.fi
.PP
.br
\fIT\fP 
.PP
.nf
!>          T is COMPLEX*16 array,
!>          dimension (LDT, N * NIRB)
!>          where NIRB = Number_of_input_row_blocks
!>                     = MAX( 1, CEIL((M-N)/(MB-N)) )
!>          Let NICB = Number_of_input_col_blocks
!>                   = CEIL(N/NB)
!>
!>          The upper-triangular block reflectors used to define the
!>          input matrices Q_in(k), k=(1:NIRB*NICB)\&. The block
!>          reflectors are stored in compact form in NIRB block
!>          reflector sequences\&. Each of NIRB block reflector sequences
!>          is stored in a larger NB-by-N column block of T and consists
!>          of NICB smaller NB-by-NB upper-triangular column blocks\&.
!>          (same format as the output T in ZLATSQR)\&.
!> 
.fi
.PP
.br
\fILDT\fP 
.PP
.nf
!>          LDT is INTEGER
!>          The leading dimension of the array T\&.
!>          LDT >= max(1,min(NB1,N))\&.
!> 
.fi
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.br
\fIWORK\fP 
.PP
.nf
!>          (workspace) COMPLEX*16 array, dimension (MAX(2,LWORK))
!>          On exit, if INFO = 0, WORK(1) returns the optimal LWORK\&.
!> 
.fi
.PP
.br
\fILWORK\fP 
.PP
.nf
!>          LWORK is INTEGER
!>          The dimension of the array WORK\&.  LWORK >= (M+NB)*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\&.
!> 
.fi
.PP
.br
\fIINFO\fP 
.PP
.nf
!>          INFO is INTEGER
!>          = 0:  successful exit
!>          < 0:  if INFO = -i, the i-th argument had an illegal value
!> 
.fi
.PP
 
.RE
.PP
\fBAuthor\fP
.RS 4
Univ\&. of Tennessee 

.PP
Univ\&. of California Berkeley 

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Univ\&. of Colorado Denver 

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NAG Ltd\&. 
.RE
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\fBContributors:\fP
.RS 4

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.nf
!>
!> November 2019, Igor Kozachenko,
!>                Computer Science Division,
!>                University of California, Berkeley
!>
!> 
.fi
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.RE
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Definition at line \fB174\fP of file \fBzungtsqr\&.f\fP\&.
.SH "Author"
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Generated automatically by Doxygen for LAPACK from the source code\&.