table of contents
/home/abuild/rpmbuild/BUILD/lapack-3.12.0/TESTING/MATGEN/zlatm2.f(3) | Library Functions Manual | /home/abuild/rpmbuild/BUILD/lapack-3.12.0/TESTING/MATGEN/zlatm2.f(3) |
NAME¶
/home/abuild/rpmbuild/BUILD/lapack-3.12.0/TESTING/MATGEN/zlatm2.f
SYNOPSIS¶
Functions/Subroutines¶
complex *16 function ZLATM2 (m, n, i, j, kl, ku, idist,
iseed, d, igrade, dl, dr, ipvtng, iwork, sparse)
ZLATM2
Function/Subroutine Documentation¶
complex*16 function ZLATM2 (integer m, integer n, integer i, integer j, integer kl, integer ku, integer idist, integer, dimension( 4 ) iseed, complex*16, dimension( * ) d, integer igrade, complex*16, dimension( * ) dl, complex*16, dimension( * ) dr, integer ipvtng, integer, dimension( * ) iwork, double precision sparse)¶
ZLATM2
Purpose:
!> !> ZLATM2 returns the (I,J) entry of a random matrix of dimension !> (M, N) described by the other parameters. It is called by the !> ZLATMR routine in order to build random test matrices. No error !> checking on parameters is done, because this routine is called in !> a tight loop by ZLATMR which has already checked the parameters. !> !> Use of ZLATM2 differs from CLATM3 in the order in which the random !> number generator is called to fill in random matrix entries. !> With ZLATM2, the generator is called to fill in the pivoted matrix !> columnwise. With ZLATM3, the generator is called to fill in the !> matrix columnwise, after which it is pivoted. Thus, ZLATM3 can !> be used to construct random matrices which differ only in their !> order of rows and/or columns. ZLATM2 is used to construct band !> matrices while avoiding calling the random number generator for !> entries outside the band (and therefore generating random numbers !> !> The matrix whose (I,J) entry is returned is constructed as !> follows (this routine only computes one entry): !> !> If I is outside (1..M) or J is outside (1..N), return zero !> (this is convenient for generating matrices in band format). !> !> Generate a matrix A with random entries of distribution IDIST. !> !> Set the diagonal to D. !> !> Grade the matrix, if desired, from the left (by DL) and/or !> from the right (by DR or DL) as specified by IGRADE. !> !> Permute, if desired, the rows and/or columns as specified by !> IPVTNG and IWORK. !> !> Band the matrix to have lower bandwidth KL and upper !> bandwidth KU. !> !> Set random entries to zero as specified by SPARSE. !>
Parameters
M
!> M is INTEGER !> Number of rows of matrix. Not modified. !>
N
!> N is INTEGER !> Number of columns of matrix. Not modified. !>
I
!> I is INTEGER !> Row of entry to be returned. Not modified. !>
J
!> J is INTEGER !> Column of entry to be returned. Not modified. !>
KL
!> KL is INTEGER !> Lower bandwidth. Not modified. !>
KU
!> KU is INTEGER !> Upper bandwidth. Not modified. !>
IDIST
!> IDIST is INTEGER !> On entry, IDIST specifies the type of distribution to be !> used to generate a random matrix . !> 1 => real and imaginary parts each UNIFORM( 0, 1 ) !> 2 => real and imaginary parts each UNIFORM( -1, 1 ) !> 3 => real and imaginary parts each NORMAL( 0, 1 ) !> 4 => complex number uniform in DISK( 0 , 1 ) !> Not modified. !>
ISEED
!> ISEED is INTEGER array of dimension ( 4 ) !> Seed for random number generator. !> Changed on exit. !>
D
!> D is COMPLEX*16 array of dimension ( MIN( I , J ) ) !> Diagonal entries of matrix. Not modified. !>
IGRADE
!> IGRADE is INTEGER !> Specifies grading of matrix as follows: !> 0 => no grading !> 1 => matrix premultiplied by diag( DL ) !> 2 => matrix postmultiplied by diag( DR ) !> 3 => matrix premultiplied by diag( DL ) and !> postmultiplied by diag( DR ) !> 4 => matrix premultiplied by diag( DL ) and !> postmultiplied by inv( diag( DL ) ) !> 5 => matrix premultiplied by diag( DL ) and !> postmultiplied by diag( CONJG(DL) ) !> 6 => matrix premultiplied by diag( DL ) and !> postmultiplied by diag( DL ) !> Not modified. !>
DL
!> DL is COMPLEX*16 array ( I or J, as appropriate ) !> Left scale factors for grading matrix. Not modified. !>
DR
!> DR is COMPLEX*16 array ( I or J, as appropriate ) !> Right scale factors for grading matrix. Not modified. !>
IPVTNG
!> IPVTNG is INTEGER !> On entry specifies pivoting permutations as follows: !> 0 => none. !> 1 => row pivoting. !> 2 => column pivoting. !> 3 => full pivoting, i.e., on both sides. !> Not modified. !>
IWORK
!> IWORK is INTEGER array ( I or J, as appropriate ) !> This array specifies the permutation used. The !> row (or column) in position K was originally in !> position IWORK( K ). !> This differs from IWORK for ZLATM3. Not modified. !>
SPARSE
!> SPARSE is DOUBLE PRECISION between 0. and 1. !> On entry specifies the sparsity of the matrix !> if sparse matrix is to be generated. !> SPARSE should lie between 0 and 1. !> A uniform ( 0, 1 ) random number x is generated and !> compared to SPARSE; if x is larger the matrix entry !> is unchanged and if x is smaller the entry is set !> to zero. Thus on the average a fraction SPARSE of the !> entries will be set to zero. !> Not modified. !>
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 209 of file zlatm2.f.
Author¶
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