/home/abui.../sdrvrfp.f(3)

💅 SDRVRFP — the sdrvrfp.f(3) glow-up

okay so bestie, welcome to the Library Functions Manual entry for /home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/TESTING/LIN/sdrvrfp.f — yes the whole path, she's a long one, we respect her 💖

---

✨ NAME ✨

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/TESTING/LIN/sdrvrfp.f — that's the file, that's the whole name, no notes 💅

---

🦋 SYNOPSIS 🦋

Functions/Subroutines

the subroutine itself, in all her glory:

subroutine SDRVRFP (nout, nn, nval, nns, nsval, nnt, ntval, thresh, a,
    asav, afac, ainv, b, bsav, xact, x, arf, arfinv, s_work_slatms,
    s_work_spot01, s_temp_spot02, s_temp_spot03, s_work_slansy,
    s_work_spot02, s_work_spot03)

she's giving SDRVRFP and honestly? iconic 👑

---

🌸 Function/Subroutine Documentation 🌸

🎀 subroutine SDRVRFP

the full signature with every type spelled out, because we do NOT skim here, periodt:

subroutine SDRVRFP (integer nout, integer nn, integer, dimension( nn ) nval,
    integer nns, integer, dimension( nns ) nsval, integer nnt, integer,
    dimension( nnt ) ntval, real thresh, real, dimension( * ) a, real,
    dimension( * ) asav, real, dimension( * ) afac, real, dimension( * )
    ainv, real, dimension( * ) b, real, dimension( * ) bsav, real,
    dimension( * ) xact, real, dimension( * ) x, real, dimension( * ) arf,
    real, dimension( * ) arfinv, real, dimension( * ) s_work_slatms, real,
    dimension( * ) s_work_spot01, real, dimension( * ) s_temp_spot02, real,
    dimension( * ) s_temp_spot03, real, dimension( * ) s_work_slansy, real,
    dimension( * ) s_work_spot02, real, dimension( * ) s_work_spot03)

SDRVRFP ✨ (yes, that's her name, twice, she's that confident)

---

💜 Purpose 💜

okay so what does she actually do? buckle up 🫶

SDRVRFP tests the LAPACK RFP routines:

• SPFTRF
• SPFTRS
• SPFTRI

this testing routine follows the same tests as DDRVPO (which is the test for the full-format Symmetric Positive Definite solver) — like, same energy, different format, iykyk 💖

all the tests happen in Full Format, and the conversion back and forth from full format to RFP format is done with the routines STRTTF and STFTTR.

first, a specific matrix A of size N is created, and there are nine types of different matrixes possible:

1. Diagonal
2. Random, CNDNUM = 2
3. *First row and column zero
4. *Last row and column zero
5. *Middle row and column zero
6. Random, CNDNUM = sqrt(0.1/EPS)
7. Random, CNDNUM = 0.1/EPS
8. Scaled near underflow
9. Scaled near overflow

* — these ones test the error exits from SPFTRF, and no test ratios are computed for them. no cap, that's just how it is 🫶

a solution XACT of size N-by-NRHS gets created, and the associated right hand side B as well. then SPFTRF is called to compute L (or U), the Cholesky factor of A. then L (or U) is used to solve the linear system of equations AX = B, which gives X. then L (or U) is used to compute the inverse of A, AINV. and after all that slay, these four tests are performed 🔥:

(1) norm( L*L' - A ) / ( N * norm(A) * EPS ) or
    norm( U'*U - A ) / ( N * norm(A) * EPS ),
(2) norm(B - A*X) / ( norm(A) * norm(X) * EPS ),
(3) norm( I - A*AINV ) / ( N * norm(A) * norm(AINV) * EPS ),
(4) ( norm(X-XACT) * RCOND ) / ( norm(XACT) * EPS ),

where EPS is the machine precision, RCOND the condition number of A, and norm( . ) is the 1-norm for (1,2,3) and the inf-norm for (4) 💀 (yes, the norms switch up, keep up bestie)

errors occur when the INFO parameter is not as expected. failures occur when a test ratio is greater than THRES. literally that simple 🌈

---

⭐ Parameters ⭐

every single one of them, in order, no skipping, we are thorough in this house 🎀

• NOUT — is INTEGER. the unit number for output.
• NN — is INTEGER. the number of values of N contained in the vector NVAL.
• NVAL — is INTEGER array, dimension (NN). the values of the matrix dimension N.
• NNS — is INTEGER. the number of values of NRHS contained in the vector NSVAL.
• NSVAL — is INTEGER array, dimension (NNS). the values of the number of right-hand sides NRHS.
• NNT — is INTEGER. the number of values of MATRIX TYPE contained in the vector NTVAL.
• NTVAL — is INTEGER array, dimension (NNT). the values of matrix type (between 0 and 9 for PO/PP/PF matrices).
• THRESH — is REAL. the threshold value for the test ratios. a result is included in the output file if RESULT >= THRESH. to have every test ratio printed, use THRESH = 0.
• A — is REAL array, dimension (NMAX*NMAX).
• ASAV — is REAL array, dimension (NMAX*NMAX).
• AFAC — is REAL array, dimension (NMAX*NMAX).
• AINV — is REAL array, dimension (NMAX*NMAX).
• B — is REAL array, dimension (NMAX*MAXRHS).
• BSAV — is REAL array, dimension (NMAX*MAXRHS).
• XACT — is REAL array, dimension (NMAX*MAXRHS).
• X — is REAL array, dimension (NMAX*MAXRHS).
• ARF — is REAL array, dimension ((NMAX*(NMAX+1))/2).
• ARFINV — is REAL array, dimension ((NMAX*(NMAX+1))/2).
• S_WORK_SLATMS — is REAL array, dimension ( 3*NMAX ). (yes, the 3* matters, don't come for me 🙈)
• S_WORK_SPOT01 — is REAL array, dimension ( NMAX ).
• S_TEMP_SPOT02 — is REAL array, dimension ( NMAX*MAXRHS ).
• S_TEMP_SPOT03 — is REAL array, dimension ( NMAX*NMAX ).
• S_WORK_SLANSY — is REAL array, dimension ( NMAX ).
• S_WORK_SPOT02 — is REAL array, dimension ( NMAX ).
• S_WORK_SPOT03 — is REAL array, dimension ( NMAX ).

---

👑 Author 👑

slay, the whole squad:

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

---

🔥 Definition 🔥

definition at line 232 of file sdrvrfp.f — go look, she's really there 💅

---

🌟 Author (the meta one) 🌟

generated automatically by Doxygen for LAPACK from the source code. not a human, but honestly? she ate 🧚

---

and that's the whole page bestie 🫶 LAPACK, Version 3.12.0 — that's the version and the vibe, sdrvrfp.f(3) forever, mwah 💖✨🎀