BLAS/SRC/dsymm.f(3)

💖 BLAS/SRC/dsymm.f — like, the LAPACK manual page but make it make sense 💖

okay bestie, gather round, because today we're decoding BLAS/SRC/dsymm.f — a whole LAPACK moment, and honestly? it's giving linear algebra main character energy ✨

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✨ NAME ✨

BLAS/SRC/dsymm.f — no cap, that's literally the whole name. short, iconic, to the point 💅

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🌸 SYNOPSIS 🌸

Functions/Subroutines

• subroutine dsymm (side, uplo, m, n, alpha, a, lda, b, ldb, beta, c, ldc)
  • and the subroutine is called DSYMM, yes queen, say it with your chest 👑

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🦋 Function/Subroutine Documentation 🦋

subroutine dsymm (character side, character uplo, integer m, integer n,
     double precision alpha, double precision, dimension(lda,*) a, integer
     lda, double precision, dimension(ldb,*) b, integer ldb, double precision
     beta, double precision, dimension(ldc,*) c, integer ldc)

DSYMM 💫 (this is the whole personality of the file, fr fr)

🎀 Purpose:

so the tea is: DSYMM performs one of the matrix-matrix operations

C := alpha*A*B + beta*C,

or

C := alpha*B*A + beta*C,

where alpha and beta are scalars, A is a symmetric matrix and B and C are m by n matrices. lowkey that's the whole vibe 🫶

👑 Parameters

• SIDE — SIDE is CHARACTER*1. On entry, SIDE specifies whether the symmetric matrix A appears on the left or right in the operation, like so:
  • SIDE = 'L' or 'l' → C := alpha*A*B + beta*C,
  • SIDE = 'R' or 'r' → C := alpha*B*A + beta*C,
• UPLO — UPLO is CHARACTER*1. On entry, UPLO specifies whether the upper or lower triangular part of the symmetric matrix A is to be referenced, as follows:
  • UPLO = 'U' or 'u' → Only the upper triangular part of the symmetric matrix is to be referenced.
  • UPLO = 'L' or 'l' → Only the lower triangular part of the symmetric matrix is to be referenced.
• M — M is INTEGER. On entry, M specifies the number of rows of the matrix C. M must be at least zero. (zero is allowed, she's generous like that 💜)
• N — N is INTEGER. On entry, N specifies the number of columns of the matrix C. N must be at least zero.
• ALPHA — ALPHA is DOUBLE PRECISION. On entry, ALPHA specifies the scalar alpha. just a lil scalar, doing her thing 🌸
• A — A is DOUBLE PRECISION array, dimension ( LDA, ka ), where ka is m when SIDE = 'L' or 'l' and is n otherwise.
  • Before entry with SIDE = 'L' or 'l', the m by m part of the array A must contain the symmetric matrix, such that when UPLO = 'U' or 'u', the leading m by m upper triangular part of the array A must contain the upper triangular part of the symmetric matrix and the strictly lower triangular part of A is not referenced, and when UPLO = 'L' or 'l', the leading m by m lower triangular part of the array A must contain the lower triangular part of the symmetric matrix and the strictly upper triangular part of A is not referenced.
  • Before entry with SIDE = 'R' or 'r', the n by n part of the array A must contain the symmetric matrix, such that when UPLO = 'U' or 'u', the leading n by n upper triangular part of the array A must contain the upper triangular part of the symmetric matrix and the strictly lower triangular part of A is not referenced, and when UPLO = 'L' or 'l', the leading n by n lower triangular part of the array A must contain the lower triangular part of the symmetric matrix and the strictly upper triangular part of A is not referenced.
  • > bestie the "not referenced" parts are not referenced. do not touch them. they are not your business 🙈
• LDA — LDA is INTEGER. On entry, LDA specifies the first dimension of A as declared in the calling (sub) program. When SIDE = 'L' or 'l' then LDA must be at least max( 1, m ), otherwise LDA must be at least max( 1, n ).
• B — B is DOUBLE PRECISION array, dimension ( LDB, N ). Before entry, the leading m by n part of the array B must contain the matrix B.
• LDB — LDB is INTEGER. On entry, LDB specifies the first dimension of B as declared in the calling (sub) program. LDB must be at least max( 1, m ).
• BETA — BETA is DOUBLE PRECISION. On entry, BETA specifies the scalar beta. When BETA is supplied as zero then C need not be set on input. (free pass, we love to see it 😌)
• C — C is DOUBLE PRECISION array, dimension ( LDC, N ). Before entry, the leading m by n part of the array C must contain the matrix C, except when beta is zero, in which case C need not be set on entry. On exit, the array C is overwritten by the m by n updated matrix. 🔥
• LDC — LDC is INTEGER. On entry, LDC specifies the first dimension of C as declared in the calling (sub) program. LDC must be at least max( 1, m ).

💫 Author

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

the whole squad, periodt 🫶

🌈 Further Details:

• Level 3 Blas routine.
• -- Written on 8-February-1989.
  • Jack Dongarra, Argonne National Laboratory.
  • Iain Duff, AERE Harwell.
  • Jeremy Du Croz, Numerical Algorithms Group Ltd.
  • Sven Hammarling, Numerical Algorithms Group Ltd.

1989?? and still serving looks. legends only 👑

Definition at line 188 of file dsymm.f. (line 188, mark it, bestie ⭐)

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🧚 Author 🧚

Generated automatically by Doxygen for LAPACK from the source code. yes, a robot wrote this and honestly it ate 💅

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and that's the whole page!! mwah 💖

Version 3.12.0 · Tue Nov 28 2023 12:08:41 · and we were all in the BLAS/SRC/dsymm.f(3) section together the whole time 🌸✨ go forth and multiply your matrices, bestie 🦋