CGET04(3)

okay so this page is CGET04(3), from the Library Functions Manual, and the header path is /home/abui...IN/cget04.f(3) (it shows up on both sides of the manual name up top, no cap). We’re folding that whole header vibe in here instead of copy-pasting the line. 💅

🌸 NAME 🌸

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/TESTING/LIN/cget04.f — that’s the name/file. Periodt. ✨

🦋 SYNOPSIS 🦋

Functions/Subroutines

subroutine CGET04 (n, nrhs, x, ldx, xact, ldxact, rcond, resid)
    CGET04

💖 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

✨ Purpose ✨

okay so CGET04 computes the difference between a computed solution and the true solution to a system of linear equations. It’s giving “residual math but make it cute.” The formula is:

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

where RCOND is the reciprocal of the condition number and EPS is the machine epsilon. 🎀

🌈 Parameters 🌈

• N — N is INTEGER; the number of rows of the matrices X and XACT. N >= 0.
• NRHS — NRHS is INTEGER; the number of columns of the matrices X and XACT. NRHS >= 0.
• X — X is COMPLEX array, dimension (LDX,NRHS); the computed solution vectors. Each vector is stored as a column of the matrix X.
• LDX — LDX is INTEGER; the leading dimension of the array X. LDX >= max(1,N).
• XACT — XACT is COMPLEX array, dimension (LDX,NRHS); the exact solution vectors. Each vector is stored as a column of the matrix XACT. (yes, the original says (LDX,NRHS) right here — we keep it exactly, bestie.)
• LDXACT — LDXACT is INTEGER; the leading dimension of the array XACT. LDXACT >= max(1,N).
• RCOND — RCOND is REAL; the reciprocal of the condition number of the coefficient matrix in the system of equations.
• RESID — RESID is REAL; the maximum over the NRHS solution vectors of ( norm(X-XACT) * RCOND ) / ( norm(XACT) * EPS ).

👑 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.

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💖 that’s the whole page, bestie 💖 Footer sign-off: LAPACK Version 3.12.0, and the trailing path is /home/abui...IN/cget04.f(3) — that’s the source/date slot on this page. Go slay those residuals. 🦋✨