/home/abui...N/zlatm1.f(3)

📦 version 3.12.0, in opensuse-leap 16.0

💅 NAME 💅

ok so bestie, this whole page is about the file /home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/TESTING/MATGEN/zlatm1.f — like, that's the whole NAME section, it's literally just the path 🫶 it's a Library Functions Manual situation (section 3, iykyk).

✨ SYNOPSIS ✨

🌸 Functions/Subroutines

subroutine ZLATM1 (mode, cond, irsign, idist, iseed, d, n, info)

ZLATM1 — that's her, that's the main character 👑

🎀 Function/Subroutine Documentation 🎀

subroutine ZLATM1 (integer mode, double precision cond, integer irsign,
    integer idist, integer, dimension( 4 ) iseed, complex*16, dimension( * )
    d, integer n, integer info)

ZLATM1 ⭐

💖 Purpose: 💖

!>
!>    ZLATM1 computes the entries of D(1..N) as specified by
!>    MODE, COND and IRSIGN. IDIST and ISEED determine the generation
!>    of random numbers. ZLATM1 is called by ZLATMR to generate
!>    random test matrices for LAPACK programs.
!>

so basically she fills in D for you based on vibes — sorry, based on MODE, COND and IRSIGN — and the randomness comes from IDIST and ISEED. no cap she's a supporting character: ZLATMR calls her to cook up 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.
!>

ok so MODE is the whole personality of this call, it decides everything about how D gets computed. the negative-MODE thing is the iconic plot twist: it means the same as ABS(MODE) but the elements of D come out reversed. so positive MODE → D ranges 1 to 1/COND, negative → 1/COND to 1 💫 she is Not modified though, so no take-backs.

COND 📏

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

COND is DOUBLE PRECISION and she's the number MODE above keeps referencing. if she gets used at all, she must be >= 1. Not modified — she's just here for the lore 🫶

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 random complex number
!>                uniformly distributed with absolute value 1
!>

IRSIGN only matters when MODE is neither -6, 0 nor 6 — then it controls the sign of D's entries. 0 means leave them alone, 1 means multiply every entry by a random complex number that's uniformly distributed with absolute value 1 🌀 gentle chaos, slay.

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.
!>

IDIST picks the distribution flavour for generating a random matrix — like choosing a boba order 🧋:

  • 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, 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 ZLATM1
!>           to continue the same random number sequence.
!>           Changed on exit.
!>

ISEED is an INTEGER array, dimension ( 4 ), and it's the seed of the random number generator. the RNG runs a linear congruential sequence limited to small integers, so it should produce machine independent random numbers — iconic, portable, no cap 🍓 the values of ISEED get changed on exit, and you can pass them into the next call to ZLATM1 to continue the same random number sequence. it's giving save file 🎮

D 💎

!>          D is COMPLEX*16 array, dimension ( N )
!>           Array to be computed according to MODE, COND and IRSIGN.
!>           May be changed on exit if MODE is nonzero.
!>

D is the COMPLEX*16 array, dimension ( N ) — the actual star of the show, computed according to MODE, COND and IRSIGN. May be changed on exit if MODE is nonzero 👀 she's mutable bestie.

N 🔢

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

N is an INTEGER, it's the number of entries of D. Not modified — she's just the count 🤍

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 4
!>           -7  => if N negative
!>

INFO is the vibe check at the end 🚦:

  • 0 => normal termination (we ate 💅)
  • -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 4
  • -7 => if N negative

👑 Author 👑

  • Univ. of Tennessee
  • Univ. of California Berkeley
  • Univ. of Colorado Denver
  • NAG Ltd.

📍 Definition at line 136 of file zlatm1.f.

💜 Author (again, yes really) 💜

Generated automatically by Doxygen for LAPACK from the source code. not a human, just a little robot doing her best 🤖✨

fr fr that's the whole page, every flag and error code accounted for, nothing skipped 🫶

ok bye bestie, go forth and generate those random test matrices 🌈💖

LAPACK · Version 3.12.0 · /home/abui...N/zlatm1.f(3) — mwah, stan this manpage, periodt 🎀💅

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