TESTING/EIG/sget31.f(3)

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version 3.12.1 · 3 versions
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This is TESTING/EIG/sget31.f(3) from the Library Functions Manual — okay so welcome to the sget31 page, bestie, it’s giving very specific LAPACK testing energy and we’re here for it 💅✨

🎀 NAME 🎀

TESTING/EIG/sget31.f — yep, that’s the file name, periodt 🫶

✨ SYNOPSIS ✨

Functions/Subroutines

  • subroutine sget31 (rmax, lmax, ninfo, knt) — SGET31

🦋 Function/Subroutine Documentation 🦋

subroutine sget31 (real rmax, integer lmax, integer, dimension( 2 ) ninfo,
     integer knt)
    SGET31

🎯 Purpose 🎯

SGET31 tests SLALN2, a routine for solving

    (ca A - w D)X = sB

where A is an NA by NA matrix (NA=1 or 2 only), w is a real (NW=1) or complex (NW=2) constant, ca is a real constant, D is an NA by NA real diagonal matrix, and B is an NA by NW matrix (when NW=2 the second column of B contains the imaginary part of the solution). The code returns X and s, where s is a scale factor, less than or equal to 1, which is chosen to avoid overflow in X.

If any singular values of ca A-w D are less than another input parameter SMIN, they are perturbed up to SMIN.

The test condition is that the scaled residual

    norm( (ca A-w D)*X - s*B ) /
          ( max( ulp*norm(ca A-w D), SMIN )*norm(X) )

should be on the order of 1. Here, ulp is the machine precision. Also, it is verified that SCALE is less than or equal to 1, and that XNORM = infinity-norm(X).

🍓 Parameters 🍓

RMAX

RMAX is REAL — value of the largest test ratio. 🔥

LMAX

LMAX is INTEGER — example number where largest test ratio achieved.

NINFO

NINFO is INTEGER array, dimension (2):

  • NINFO(1) = number of examples with INFO less than 0
  • NINFO(2) = number of examples with INFO greater than 0

KNT

KNT is INTEGER — total number of examples tested. 💖

💖 Author 💖

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

Definition at line 90 of file sget31.f.

🫶 Author 🫶

Generated automatically by Doxygen for LAPACK from the source code.

That’s the whole page, bestie — source/version vibe check: LAPACK Version 3.12.0, and the page is TESTING/EIG/sget31.f(3). Slay, you made it to the end 🎀💜✨

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