
cgbbrd.f(3) LAPACK cgbbrd.f(3)
NAME
cgbbrd.f 
SYNOPSIS
Functions/Subroutines
subroutine cgbbrd (VECT, M, N, NCC, KL, KU, AB, LDAB, D, E, Q, LDQ, PT, LDPT, C, LDC,
WORK, RWORK, INFO)
CGBBRD
Function/Subroutine Documentation
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)
CGBBRD
Purpose:
CGBBRD reduces a complex general mbyn 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.
Parameters:
VECT
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.
M
M is INTEGER
The number of rows of the matrix A. M >= 0.
N
N is INTEGER
The number of columns of the matrix A. N >= 0.
NCC
NCC is INTEGER
The number of columns of the matrix C. NCC >= 0.
KL
KL is INTEGER
The number of subdiagonals of the matrix A. KL >= 0.
KU
KU is INTEGER
The number of superdiagonals of the matrix A. KU >= 0.
AB
AB is COMPLEX array, dimension (LDAB,N)
On entry, the mbyn band matrix A, stored in rows 1 to
KL+KU+1. The jth column of A is stored in the jth column of
the array AB as follows:
AB(ku+1+ij,j) = A(i,j) for max(1,jku)<=i<=min(m,j+kl).
On exit, A is overwritten by values generated during the
reduction.
LDAB
LDAB is INTEGER
The leading dimension of the array A. LDAB >= KL+KU+1.
D
D is REAL array, dimension (min(M,N))
The diagonal elements of the bidiagonal matrix B.
E
E is REAL array, dimension (min(M,N)1)
The superdiagonal elements of the bidiagonal matrix B.
Q
Q is COMPLEX array, dimension (LDQ,M)
If VECT = 'Q' or 'B', the mbym unitary matrix Q.
If VECT = 'N' or 'P', the array Q is not referenced.
LDQ
LDQ is INTEGER
The leading dimension of the array Q.
LDQ >= max(1,M) if VECT = 'Q' or 'B'; LDQ >= 1 otherwise.
PT
PT is COMPLEX array, dimension (LDPT,N)
If VECT = 'P' or 'B', the nbyn unitary matrix P'.
If VECT = 'N' or 'Q', the array PT is not referenced.
LDPT
LDPT is INTEGER
The leading dimension of the array PT.
LDPT >= max(1,N) if VECT = 'P' or 'B'; LDPT >= 1 otherwise.
C
C is COMPLEX array, dimension (LDC,NCC)
On entry, an mbyncc matrix C.
On exit, C is overwritten by Q**H*C.
C is not referenced if NCC = 0.
LDC
LDC is INTEGER
The leading dimension of the array C.
LDC >= max(1,M) if NCC > 0; LDC >= 1 if NCC = 0.
WORK
WORK is COMPLEX array, dimension (max(M,N))
RWORK
RWORK is REAL array, dimension (max(M,N))
INFO
INFO is INTEGER
= 0: successful exit.
< 0: if INFO = i, the ith argument had an illegal value.
Author:
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
November 2011
Definition at line 193 of file cgbbrd.f.
Author
Generated automatically by Doxygen for LAPACK from the source code.
Version 3.4.2 Tue Sep 25 2012 cgbbrd.f(3) 
