.TH "cgbbrd.f" 3 "Wed Oct 15 2014" "Version 3.4.2" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME cgbbrd.f \- .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "subroutine \fBcgbbrd\fP (VECT, M, N, NCC, KL, KU, AB, LDAB, D, E, Q, LDQ, PT, LDPT, C, LDC, WORK, RWORK, INFO)" .br .RI "\fI\fBCGBBRD\fP \fP" .in -1c .SH "Function/Subroutine Documentation" .PP .SS "subroutine cgbbrd (characterVECT, integerM, integerN, integerNCC, integerKL, integerKU, complex, dimension( ldab, * )AB, integerLDAB, real, dimension( * )D, real, dimension( * )E, complex, dimension( ldq, * )Q, integerLDQ, complex, dimension( ldpt, * )PT, integerLDPT, complex, dimension( ldc, * )C, integerLDC, complex, dimension( * )WORK, real, dimension( * )RWORK, integerINFO)" .PP \fBCGBBRD\fP .PP \fBPurpose: \fP .RS 4 .PP .nf CGBBRD reduces a complex general m-by-n band matrix A to real upper bidiagonal form B by a unitary transformation: Q**H * A * P = B. The routine computes B, and optionally forms Q or P**H, or computes Q**H*C for a given matrix C. .fi .PP .RE .PP \fBParameters:\fP .RS 4 \fIVECT\fP .PP .nf VECT is CHARACTER*1 Specifies whether or not the matrices Q and P**H are to be formed. = 'N': do not form Q or P**H; = 'Q': form Q only; = 'P': form P**H only; = 'B': form both. .fi .PP .br \fIM\fP .PP .nf M is INTEGER The number of rows of the matrix A. M >= 0. .fi .PP .br \fIN\fP .PP .nf N is INTEGER The number of columns of the matrix A. N >= 0. .fi .PP .br \fINCC\fP .PP .nf NCC is INTEGER The number of columns of the matrix C. NCC >= 0. .fi .PP .br \fIKL\fP .PP .nf KL is INTEGER The number of subdiagonals of the matrix A. KL >= 0. .fi .PP .br \fIKU\fP .PP .nf KU is INTEGER The number of superdiagonals of the matrix A. KU >= 0. .fi .PP .br \fIAB\fP .PP .nf AB is COMPLEX array, dimension (LDAB,N) On entry, the m-by-n band matrix A, stored in rows 1 to KL+KU+1. The j-th column of A is stored in the j-th column of the array AB as follows: AB(ku+1+i-j,j) = A(i,j) for max(1,j-ku)<=i<=min(m,j+kl). On exit, A is overwritten by values generated during the reduction. .fi .PP .br \fILDAB\fP .PP .nf LDAB is INTEGER The leading dimension of the array A. LDAB >= KL+KU+1. .fi .PP .br \fID\fP .PP .nf D is REAL array, dimension (min(M,N)) The diagonal elements of the bidiagonal matrix B. .fi .PP .br \fIE\fP .PP .nf E is REAL array, dimension (min(M,N)-1) The superdiagonal elements of the bidiagonal matrix B. .fi .PP .br \fIQ\fP .PP .nf Q is COMPLEX array, dimension (LDQ,M) If VECT = 'Q' or 'B', the m-by-m unitary matrix Q. If VECT = 'N' or 'P', the array Q is not referenced. .fi .PP .br \fILDQ\fP .PP .nf LDQ is INTEGER The leading dimension of the array Q. LDQ >= max(1,M) if VECT = 'Q' or 'B'; LDQ >= 1 otherwise. .fi .PP .br \fIPT\fP .PP .nf PT is COMPLEX array, dimension (LDPT,N) If VECT = 'P' or 'B', the n-by-n unitary matrix P'. If VECT = 'N' or 'Q', the array PT is not referenced. .fi .PP .br \fILDPT\fP .PP .nf LDPT is INTEGER The leading dimension of the array PT. LDPT >= max(1,N) if VECT = 'P' or 'B'; LDPT >= 1 otherwise. .fi .PP .br \fIC\fP .PP .nf C is COMPLEX array, dimension (LDC,NCC) On entry, an m-by-ncc matrix C. On exit, C is overwritten by Q**H*C. C is not referenced if NCC = 0. .fi .PP .br \fILDC\fP .PP .nf LDC is INTEGER The leading dimension of the array C. LDC >= max(1,M) if NCC > 0; LDC >= 1 if NCC = 0. .fi .PP .br \fIWORK\fP .PP .nf WORK is COMPLEX array, dimension (max(M,N)) .fi .PP .br \fIRWORK\fP .PP .nf RWORK is REAL array, dimension (max(M,N)) .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 .PP Univ\&. of Colorado Denver .PP NAG Ltd\&. .RE .PP \fBDate:\fP .RS 4 November 2011 .RE .PP .PP Definition at line 193 of file cgbbrd\&.f\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.