Purpose
To multiply the M by N real matrix A by the real scalar CTO/CFROM. This is done without over/underflow as long as the final result CTO*A(I,J)/CFROM does not over/underflow. TYPE specifies that A may be full, (block) upper triangular, (block) lower triangular, (block) upper Hessenberg, or banded.Specification
SUBROUTINE MB01QD( TYPE, M, N, KL, KU, CFROM, CTO, NBL, NROWS, A,
$ LDA, INFO )
C .. Scalar Arguments ..
CHARACTER TYPE
INTEGER INFO, KL, KU, LDA, M, N, NBL
DOUBLE PRECISION CFROM, CTO
C .. Array Arguments ..
INTEGER NROWS ( * )
DOUBLE PRECISION A( LDA, * )
Arguments
Mode Parameters
TYPE CHARACTER*1
TYPE indices the storage type of the input matrix.
= 'G': A is a full matrix.
= 'L': A is a (block) lower triangular matrix.
= 'U': A is a (block) upper triangular matrix.
= 'H': A is a (block) upper Hessenberg matrix.
= 'B': A is a symmetric band matrix with lower bandwidth
KL and upper bandwidth KU and with the only the
lower half stored.
= 'Q': A is a symmetric band matrix with lower bandwidth
KL and upper bandwidth KU and with the only the
upper half stored.
= 'Z': A is a band matrix with lower bandwidth KL and
upper bandwidth KU.
Input/Output Parameters
M (input) INTEGER
The number of rows of the matrix A. M >= 0.
N (input) INTEGER
The number of columns of the matrix A. N >= 0.
KL (input) INTEGER
The lower bandwidth of A. Referenced only if TYPE = 'B',
'Q' or 'Z'.
KU (input) INTEGER
The upper bandwidth of A. Referenced only if TYPE = 'B',
'Q' or 'Z'.
CFROM (input) DOUBLE PRECISION
CTO (input) DOUBLE PRECISION
The matrix A is multiplied by CTO/CFROM. A(I,J) is
computed without over/underflow if the final result
CTO*A(I,J)/CFROM can be represented without over/
underflow. CFROM must be nonzero.
NBL (input) INTEGER
The number of diagonal blocks of the matrix A, if it has a
block structure. To specify that matrix A has no block
structure, set NBL = 0. NBL >= 0.
NROWS (input) INTEGER array, dimension max(1,NBL)
NROWS(i) contains the number of rows and columns of the
i-th diagonal block of matrix A. The sum of the values
NROWS(i), for i = 1: NBL, should be equal to min(M,N).
The array NROWS is not referenced if NBL = 0.
A (input/output) DOUBLE PRECISION array, dimension (LDA,N)
The matrix to be multiplied by CTO/CFROM. See TYPE for
the storage type.
LDA (input) INTEGER
The leading dimension of the array A. LDA >= max(1,M).
Error Indicator
INFO INTEGER
Not used in this implementation.
Method
Matrix A is multiplied by the real scalar CTO/CFROM, taking into account the specified storage mode of the matrix. MB01QD is a version of the LAPACK routine DLASCL, modified for dealing with block triangular, or block Hessenberg matrices. For efficiency, no tests of the input scalar parameters are performed.Further Comments
NoneExample
Program Text
NoneProgram Data
NoneProgram Results
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