ZSPT02(3)

💅 ZSPT02(3) — the residual-girlie of LAPACK (that's section 3 of the manual, bestie)

okay so real talk, this page lives at /home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/TESTING/LIN/zspt02.f and honestly the path is longer than my attention span. but she's iconic, so let's get into it 🎀

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✨ SYNOPSIS ✨

🫶 Functions/Subroutines

subroutine ZSPT02 (uplo, n, nrhs, a, x, ldx, b, ldb, rwork, resid)

ZSPT02 — that's her. that's the whole name. slay.

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💖 Function/Subroutine Documentation 💖

subroutine ZSPT02 (character uplo, integer n, integer nrhs, complex*16,
    dimension( * ) a, complex*16, dimension( ldx, * ) x, integer ldx,
    complex*16, dimension( ldb, * ) b, integer ldb, double precision,
    dimension( * ) rwork, double precision resid)

ZSPT02 👑 (yes the signature is doing the absolute most, but every single type spec is load-bearing, ngl)

🌸 Purpose

!> peep the comment block, it's giving documentation-core:

!>`` ZSPT02 computes the residual in the solution of a complex symmetric !> `system of linear equations A*x = b when packed storage is used for` `!> the coefficient matrix. The ratio computed is !> !>`` RESID = norm( B - A*X ) / ( norm(A) * norm(X) * EPS). !> !>`` where EPS is the machine precision.

so basically she checks how badly you fumbled the solve 😭 and reports the ratio. it's giving quality control.

🦋 Parameters

• UPLO — !>`` UPLO is CHARACTER*1 !> `Specifies whether the upper or lower triangular part of the` `!> complex symmetric matrix A is stored: !>`` = 'U': Upper triangular !>`` = 'L': Lower triangular — pick your fighter: upper or lower, no in-between 💅
• N — !>`` N is INTEGER !>`` The number of rows and columns of the matrix A. N >= 0. — rows and columns, so she's square, and she refuses to go negative. we respect the boundary. 🫶
• NRHS — !>`` NRHS is INTEGER !> `The number of columns of B, the matrix of right hand sides.` `!> NRHS >= 0. — how many right-hand sides we're serving today. zero is valid, we don't judge. ✨
• A — !>`` A is COMPLEX*16 array, dimension (N*(N+1)/2) !> `The original complex symmetric matrix A, stored as a packed` `!> triangular matrix. — packed storage, so she's compact and mysterious. N*(N+1)/2 is the whole vibe. 🎀
• X — !>`` X is COMPLEX*16 array, dimension (LDX,NRHS) !> `The computed solution vectors for the system of linear` `!> equations. — the answers your solver claims it produced. we're checking receipts. 🔥
• LDX — !>`` LDX is INTEGER !>`` The leading dimension of the array X. LDX >= max(1,N). — LDX >= max(1,N), no exceptions, don't test her. 💀
• B — !>`` B is COMPLEX*16 array, dimension (LDB,NRHS) !> `On entry, the right hand side vectors for the system of` `!> linear equations. !>`` On exit, B is overwritten with the difference B - A*X.— ⚠️ heads up bestie: she *overwrites*Bon exit withB - A*X`. your original right-hand sides? gone. consider yourself warned 🫶
• LDB — !>`` LDB is INTEGER !>`` The leading dimension of the array B. LDB >= max(1,N). — same energy as LDX, LDB >= max(1,N). respect the leading dimension. 🌈
• RWORK — !>`` RWORK is DOUBLE PRECISION array, dimension (N)— double precision scratch space of sizeN`. her little workspace. ⭐
• RESID — !>`` RESID is DOUBLE PRECISION !> `The maximum over the number of right hand sides of` `!> norm(B - A*X) / ( norm(A) * norm(X) * EPS ). — the final score: the max over all the right-hand sides of norm(B - A*X) / ( norm(A) * norm(X) * EPS ). low number = ate. high number = 💀

🧚 Author

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

🍓 Definition at line 121 of file zspt02.f.

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🌈 Author (the meta one)

Generated automatically by Doxygen for LAPACK from the source code. (she didn't write her own bio, the machine did it for her. main character energy fr fr 🙈)

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ok that's the whole page, no cap. every flag, every bound, every !> comment preserved, because we keep the facts and serve the vibe. periodt. 💅

LAPACK — Version 3.12.0 🌸 and the source path <cyan>/home/abui...IN/zspt02.f(3)</cyan> is stamped on the bottom like a lil' signature. mwah, bye bestie 🫶✨