SSYRK(3)

✨ NAME ✨

okay so bestie, this is the Library Functions Manual page for ssyrk.f — and the whole name is literally:

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

The page header also tags it as /home/abui...SRC/ssyrk.f(3), which is giving abbreviated but still iconic. 💅

🌸 SYNOPSIS 🌸

Functions/Subroutines

subroutine SSYRK (uplo, trans, n, k, alpha, a, lda, beta, c, ldc)
           SSYRK

💖 Function/Subroutine Documentation 💖

🫶 subroutine SSYRK 🫶

subroutine SSYRK (character uplo, character trans, integer n, integer k,
       real alpha, real, dimension(lda,*) a, integer lda, real beta, real,
       dimension(ldc,*) c, integer ldc)
       SSYRK

SSYRK. That's the subroutine, periodt. 💅

🌈 Purpose 🌈

okay so SSYRK performs one of the symmetric rank k operations:

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

or

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

where alpha and beta are scalars, C is an n by n symmetric matrix and A is an n by k matrix in the first case and a k by n matrix in the second case. 🦋

🍓 Parameters 🍓

• UPLO is CHARACTER*1. On entry, UPLO specifies whether the upper or lower triangular part of the array C is to be referenced as follows:
  • UPLO = 'U' or 'u' — Only the upper triangular part of C is to be referenced.
  • UPLO = 'L' or 'l' — Only the lower triangular part of C is to be referenced.
• TRANS is CHARACTER*1. On entry, TRANS specifies the operation to be performed as follows:
  • TRANS = 'N' or 'n' — C := alpha*A*A**T + beta*C.
  • TRANS = 'T' or 't' — C := alpha*A**T*A + beta*C.
  • TRANS = 'C' or 'c' — C := alpha*A**T*A + beta*C.
• N is INTEGER. On entry, N specifies the order of the matrix C. N must be at least zero.
• K is INTEGER. On entry with TRANS = 'N' or 'n', K specifies the number of columns of the matrix A, and on entry with TRANS = 'T' or 't' or 'C' or 'c', K specifies the number of rows of the matrix A. K must be at least zero.
• ALPHA is REAL. On entry, ALPHA specifies the scalar alpha.
• A is REAL array, dimension ( LDA, ka ), where ka is k when TRANS = 'N' or 'n', and is n otherwise. Before entry with TRANS = 'N' or 'n', the leading n by k part of the array A must contain the matrix A, otherwise the leading k by n part of the array A must contain the matrix A.
• LDA is INTEGER. On entry, LDA specifies the first dimension of A as declared in the calling (sub) program. When TRANS = 'N' or 'n' then LDA must be at least max( 1, n ), otherwise LDA must be at least max( 1, k ).
• BETA is REAL. On entry, BETA specifies the scalar beta.
• C is REAL array, dimension ( LDC, N ). Before entry with UPLO = 'U' or 'u', the leading n by n upper triangular part of the array C must contain the upper triangular part of the symmetric matrix and the strictly lower triangular part of C is not referenced. On exit, the upper triangular part of the array C is overwritten by the upper triangular part of the updated matrix. Before entry with UPLO = 'L' or 'l', the leading n by n lower triangular part of the array C must contain the lower triangular part of the symmetric matrix and the strictly upper triangular part of C is not referenced. On exit, the lower triangular part of the array C is overwritten by the lower triangular part of the updated matrix.
• 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, n ).

👑 Author 👑

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

🔥 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.

📍 Definition 📍

Definition at line 168 of file ssyrk.f.

🦋 Author 🦋

Generated automatically by Doxygen for LAPACK from the source code.

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k bye bestie 💜 — this page is LAPACK Version 3.12.0, and the footer path is /home/abui...SRC/ssyrk.f(3). Stay symmetric, slay the rank-k update, and don't forget the vibes. 🫶✨