TESTING/LIN/cget04.f(3)

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version 3.12.1 · 2 versions
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🦋 NAME 🦋

Okay bestie, welcome to the TESTING/LIN/cget04.f page from the Library Functions Manual 💅✨ — this is the CGET04 subroutine’s whole moment, and no cap, every detail is staying right here.

TESTING/LIN/cget04.f — yes, that’s the file name, and CGET04 is the star of the show 🎀

✨ SYNOPSIS ✨

🧚 Functions/Subroutines 🧚

subroutine cget04 (n, nrhs, x, ldx, xact, ldxact, rcond, resid)

CGET04 — icon behavior only 🔥

🎀 Function/Subroutine Documentation 🎀

subroutine cget04 (integer n, integer nrhs, complex, dimension( ldx, * ) x,
    integer ldx, complex, dimension( ldxact, * ) xact, integer ldxact, real
    rcond, real resid)

CGET04 — she’s documented, she’s precise, she’s booked and busy 💖

💜 Purpose 💜

Bestie, CGET04 computes the difference between a computed solution and the true solution to a system of linear equations 🧮✨

The formula is literally:

RESID =  ( norm(X-XACT) * RCOND ) / ( norm(XACT) * EPS ),

where RCOND is the reciprocal of the condition number and EPS is the machine epsilon. That’s the whole numerical vibe check 🫶

🍓 Parameters 🍓

  • N — N is INTEGER; it’s the number of rows of the matrices X and XACT. Bestie, N >= 0 💅
  • NRHS — NRHS is INTEGER; it’s the number of columns of the matrices X and XACT. And yes, NRHS >= 0 ✨
  • X — X is COMPLEX array, dimension (LDX,NRHS); these are the computed solution vectors. Each vector is stored as a column of the matrix X, periodt 🎀
  • LDX — LDX is INTEGER; this is the leading dimension of the array X, and the rule is LDX >= max(1,N) 💖
  • XACT — XACT is COMPLEX array, dimension (LDX,NRHS); these are the exact solution vectors. Each vector is stored as a column of the matrix XACT 🌸
  • LDXACT — LDXACT is INTEGER; this is the leading dimension of the array XACT, with LDXACT >= max(1,N) 🦋
  • RCOND — RCOND is REAL; it’s the reciprocal of the condition number of the coefficient matrix in the system of equations 👑
  • RESID — RESID is REAL; it’s the maximum over the NRHS solution vectors of ( norm(X-XACT) * RCOND ) / ( norm(XACT) * EPS ) — yes, that exact formula, no edits 🔥

🫶 Author 🫶

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

Definition at line 101 of file cget04.f. 💅

🌈 Author 🌈

Generated automatically by Doxygen for LAPACK from the source code.

Footer sign-off: LAPACK · Version 3.12.0 · TESTING/LIN/cget04.f(3) — that’s the source/version/date tea from the last line, kept cute and exact, with no invented date, bestie 🫶💖✨

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