/home/abui...N/slatm7.f(3)

okay bestie, welcome to /home/abui...N/slatm7.f(3) from the Library Functions Manual — yes, the manual name is folded in right here, no boring header-line copy-paste, we're keeping it cute. This is the LAPACK slatm7.f page, and we're gonna walk through every argument, value, and error code like we're decoding the group chat. 💅✨

🌸 NAME 🌸

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/TESTING/MATGEN/slatm7.f

✨ SYNOPSIS ✨

Functions/Subroutines

• subroutine SLATM7 (mode, cond, irsign, idist, iseed, d, n, rank, info) — SLATM7

🧚 FUNCTION/SUBROUTINE DOCUMENTATION 🧚

💖 subroutine SLATM7

subroutine SLATM7 (integer mode, real cond, integer irsign, integer idist,
       integer, dimension( 4 ) iseed, real, dimension( * ) d, integer n,
       integer rank, integer info)

SLATM7

🎀 Purpose

okay so SLATM7 computes the entries of D as specified by MODE, COND and IRSIGN. IDIST and ISEED determine the generation of random numbers. SLATM7 is called by SLATMT to generate random test matrices. 🦋

• MODE — 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:RANK)=1.0/COND
  • MODE = 2 sets D(1:RANK-1)=1 and D(RANK)=1.0/COND
  • MODE = 3 sets D(I)=COND**(-(I-1)/(RANK-1)) I=1:RANK
  • 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 — REAL. On entry, used as described under MODE above. If used, it must be >= 1. Not modified.
• IRSIGN — 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 — CHARACTER*1. 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.
  • (tiny heads-up: the signature above says integer idist, while the argument description says CHARACTER*1 — both are in the original, bestie, I'm not merging them.)
• ISEED — 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 SLATM7 to continue the same random number sequence. Changed on exit.
• D — REAL array, dimension ( MIN( M , N ) ). Array to be computed according to MODE, COND and IRSIGN. May be changed on exit if MODE is nonzero.
• N — INTEGER. Number of entries of D. Not modified.
• RANK — INTEGER. The rank of matrix to be generated for modes 1,2,3 only. D( RANK+1:N ) = 0. Not modified.
• INFO — 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 120 of file slatm7.f.

👑 Author

Generated automatically by Doxygen for LAPACK from the source code.

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okay that's the whole page, bestie. Sign-off: the footer source/version is LAPACK, Version 3.12.0, and the page path is /home/abui...N/slatm7.f(3) — no extra date shown, so that's the footer in full. 🫶💖🎀