Scroll to navigation

/home/abuild/rpmbuild/BUILD/lapack-3.12.0/TESTING/MATGEN/dlatm1.f(3) Library Functions Manual /home/abuild/rpmbuild/BUILD/lapack-3.12.0/TESTING/MATGEN/dlatm1.f(3)

NAME

/home/abuild/rpmbuild/BUILD/lapack-3.12.0/TESTING/MATGEN/dlatm1.f

SYNOPSIS

Functions/Subroutines


subroutine DLATM1 (mode, cond, irsign, idist, iseed, d, n, info)
DLATM1

Function/Subroutine Documentation

subroutine DLATM1 (integer mode, double precision cond, integer irsign, integer idist, integer, dimension( 4 ) iseed, double precision, dimension( * ) d, integer n, integer info)

DLATM1

Purpose:

!>
!>    DLATM1 computes the entries of D(1..N) as specified by
!>    MODE, COND and IRSIGN. IDIST and ISEED determine the generation
!>    of random numbers. DLATM1 is called by DLATMR to generate
!>    random test matrices for LAPACK programs.
!> 

Parameters

MODE

!>          MODE is INTEGER
!>           On entry describes how D is to be computed:
!>           MODE = 0 means do not change D.
!>           MODE = 1 sets D(1)=1 and D(2:N)=1.0/COND
!>           MODE = 2 sets D(1:N-1)=1 and D(N)=1.0/COND
!>           MODE = 3 sets D(I)=COND**(-(I-1)/(N-1))
!>           MODE = 4 sets D(i)=1 - (i-1)/(N-1)*(1 - 1/COND)
!>           MODE = 5 sets D to random numbers in the range
!>                    ( 1/COND , 1 ) such that their logarithms
!>                    are uniformly distributed.
!>           MODE = 6 set D to random numbers from same distribution
!>                    as the rest of the matrix.
!>           MODE < 0 has the same meaning as ABS(MODE), except that
!>              the order of the elements of D is reversed.
!>           Thus if MODE is positive, D has entries ranging from
!>              1 to 1/COND, if negative, from 1/COND to 1,
!>           Not modified.
!> 

COND

!>          COND is DOUBLE PRECISION
!>           On entry, used as described under MODE above.
!>           If used, it must be >= 1. Not modified.
!> 

IRSIGN

!>          IRSIGN is INTEGER
!>           On entry, if MODE neither -6, 0 nor 6, determines sign of
!>           entries of D
!>           0 => leave entries of D unchanged
!>           1 => multiply each entry of D by 1 or -1 with probability .5
!> 

IDIST

!>          IDIST is INTEGER
!>           On entry, IDIST specifies the type of distribution to be
!>           used to generate a random matrix .
!>           1 => UNIFORM( 0, 1 )
!>           2 => UNIFORM( -1, 1 )
!>           3 => NORMAL( 0, 1 )
!>           Not modified.
!> 

ISEED

!>          ISEED is INTEGER array, dimension ( 4 )
!>           On entry ISEED specifies the seed of the random number
!>           generator. The random number generator uses a
!>           linear congruential sequence limited to small
!>           integers, and so should produce machine independent
!>           random numbers. The values of ISEED are changed on
!>           exit, and can be used in the next call to DLATM1
!>           to continue the same random number sequence.
!>           Changed on exit.
!> 

D

!>          D is DOUBLE PRECISION array, dimension ( N )
!>           Array to be computed according to MODE, COND and IRSIGN.
!>           May be changed on exit if MODE is nonzero.
!> 

N

!>          N is INTEGER
!>           Number of entries of D. Not modified.
!> 

INFO

!>          INFO is INTEGER
!>            0  => normal termination
!>           -1  => if MODE not in range -6 to 6
!>           -2  => if MODE neither -6, 0 nor 6, and
!>                  IRSIGN neither 0 nor 1
!>           -3  => if MODE neither -6, 0 nor 6 and COND less than 1
!>           -4  => if MODE equals 6 or -6 and IDIST not in range 1 to 3
!>           -7  => if N negative
!> 

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 134 of file dlatm1.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Version 3.12.0 LAPACK