STPSV(3)

💅 STPSV(3) — like, the packed triangular solve of your DREAMS ✨

okay bestie, so this whole page lives at /home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/BLAS/SRC/stpsv.f — that's the NAME line, she's long, she's a whole path, we stan a thorough queen 🎀

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✨ SYNOPSIS ✨

Functions/Subroutines

subroutine STPSV (uplo, trans, diag, n, ap, x, incx)

STPSV — that's her. That's the whole name. Iconic, no notes. 👑

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🦋 Function/Subroutine Documentation 🦋

subroutine STPSV (character uplo, character trans, character diag, integer
    n, real, dimension(*) ap, real, dimension(*) x, integer incx)

STPSV — say it with me now 💖

🌸 Purpose 🌸

!> STPSV solves one of the systems of equations !> A*x = b, or A**T*x = b, !> where b and x are n element vectors and A is an n by n unit, or !> non-unit, upper or lower triangular matrix, supplied in packed form. !> No test for singularity or near-singularity is included in this !> routine. Such tests must be performed before calling this routine.

so basically, bestie: she solves linear systems for you, but she is not out here checking whether your matrix is singular or nearly singular. 🫶 That's your job, no cap. Do that check before you call her, fr fr. 💀

🌈 Parameters 🌈

• UPLO — CHARACTER*1. On entry, UPLO tells her whether the matrix is upper or lower triangular, like this:
  • UPLO = 'U' or 'u' → A is an upper triangular matrix.
  • UPLO = 'L' or 'l' → A is a lower triangular matrix.
• TRANS — CHARACTER*1. On entry, TRANS says which equation situation we're in:
  • TRANS = 'N' or 'n' → A*x = b.
  • TRANS = 'T' or 't' → A**T*x = b.
  • TRANS = 'C' or 'c' → A**T*x = b.
• DIAG — CHARACTER*1. On entry, DIAG says whether A is unit triangular or not:
  • DIAG = 'U' or 'u' → A is assumed to be unit triangular.
  • DIAG = 'N' or 'n' → A is not assumed to be unit triangular.
• N — INTEGER. On entry, N is the order of the matrix A. The way that N has to be at least zero. Zero is fine, negative is not, periodt. 🚫
• AP — REAL array, dimension at least ( ( n*( n + 1 ) )/2 ). Before entry with UPLO = 'U' or 'u', the array AP must contain the upper triangular matrix packed sequentially, column by column, so that AP( 1 ) contains a( 1, 1 ), AP( 2 ) and AP( 3 ) contain a( 1, 2 ) and a( 2, 2 ) respectively, and so on. 🧚 Before entry with UPLO = 'L' or 'l', the array AP must contain the lower triangular matrix packed sequentially, column by column, so that AP( 1 ) contains a( 1, 1 ), AP( 2 ) and AP( 3 ) contain a( 2, 1 ) and a( 3, 1 ) respectively, and so on. Note that when DIAG = 'U' or 'u', the diagonal elements of A are not referenced, but are assumed to be unity. 👀 lowkey free real estate
• X — REAL array, dimension at least ( 1 + ( n - 1 )*abs( INCX ) ). Before entry, the incremented array X must contain the n element right-hand side vector b. On exit, X is overwritten with the solution vector x. 🔥 she takes your b and gives you back an x, that's the whole plot
• INCX — INTEGER. On entry, INCX specifies the increment for the elements of X. INCX must not be zero. seriously. do not. 💀

🎀 Author 🎀

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

the whole squad, iykyk 🫶

⭐ Further Details ⭐

!> Level 2 Blas routine. !> -- Written on 22-October-1986. !> Jack Dongarra, Argonne National Lab. !> Jeremy Du Croz, Nag Central Office. !> Sven Hammarling, Nag Central Office. !> Richard Hanson, Sandia National Labs.

1986!! she's been serving since the eighties, that's main character energy fr fr 👑

Definition at line 143 of file stpsv.f. ✨

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💜 Author (the meta one) 💜

Generated automatically by Doxygen for LAPACK from the source code. not a human, just vibes and a parser 🧚

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and that's the page, bestie 🌈 — LAPACK, Version 3.12.0, dated /home/abui...SRC/stpsv.f(3) on the way out. go forth and solve your triangular systems, she's rooting for you 💖🎀🦋