CSYSWAPR(3)

🌸 CSYSWAPR(3) — it's giving "swap these rows and columns" energy 🌸

okay so first things first, the manual name situation: this bad boy lives in the Library Functions Manual, and the page itself is literally /home/abui.../csyswapr.f(3). like, yes, that's the whole header. iconic of them to just. put the path there. 💅

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✨ NAME ✨

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/csyswapr.f

that's it. that's the name. it's a whole file path bestie, don't ask me why 😭

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🦋 SYNOPSIS 🦋

Functions/Subroutines

subroutine CSYSWAPR (uplo, n, a, lda, i1, i2)

CSYSWAPR — that's the whole description in the synopsis, and honestly? slay, they said "the name says it all" and moved on. 💀

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🎀 Function/Subroutine Documentation 🎀

subroutine CSYSWAPR (character uplo, integer n, complex, dimension( lda, n )
    a, integer lda, integer i1, integer i2)

CSYSWAPR 🌟

🌈 Purpose 🌈

CSYSWAPR applies an elementary permutation on the rows and the columns of a symmetric matrix.

so like, no cap: it takes your symmetric matrix and does that one elementary permutation thing on both the rows and the columns. symmetric behaviour for a symmetric matrix, we love consistency. 🫶

💜 Parameters 💜

• UPLO — UPLO is CHARACTER*1. this one tells the routine whether the details of the factorization are stored as an upper or lower triangular matrix:
  • = 'U': Upper triangular, form is A = U*D*U**T;
  • = 'L': Lower triangular, form is A = L*D*L**T.
• N — N is INTEGER. the order of the matrix A. and it's N >= 0, so no negatives pls. 🙈
• A — A is COMPLEX array, dimension (LDA,N). on entry, the N-by-N matrix A. on exit, the permuted matrix where the rows I1 and I2 and columns I1 and I2 are interchanged. and here's the tea 👑: if UPLO = 'U', the interchanges are applied to the upper triangular part and the strictly lower triangular part of A is not referenced; if UPLO = 'L', the interchanges are applied to the lower triangular part and the part of A above the diagonal is not referenced. so half of your matrix is just vibing in the background, untouched, unbothered, main character of nothing. 💅
• LDA — LDA is INTEGER. the leading dimension of the array A. LDA >= max(1,N). that's the rule, fr fr.
• I1 — I1 is INTEGER. index of the first row to swap. 🍓
• I2 — I2 is INTEGER. index of the second row to swap. 🍓

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⭐ Author ⭐

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

all of them. collectively. the group project actually got finished. 😭👏

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Definition at line 99 of file csyswapr.f.

line 99 specifically. noted. 🧚

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🌸 Author 🌸

Generated automatically by Doxygen for LAPACK from the source code.

not a human, not a vibe curator, just Doxygen doing its little thing automatically. lowkey impressive, highkey impersonal. 🤖✨

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and that's the page bestie! go swap those rows and columns, stay symmetric, and remember: the strictly lower triangular part is not referenced when UPLO = 'U'. periodt. 💖

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LAPACK — Version 3.12.0 🦋 and the page footer goes by /home/abui.../csyswapr.f(3), so that's the little signature at the bottom. mwah, bye! 💋🎀