TESTING/MATGEN/dlagsy.f(3)

📦
version 3.12.1 · 2 versions
, in arch rolling

💖 NAME 💖

okay bestie, this is TESTING/MATGEN/dlagsy.f from the Library Functions Manual — aka the page for the dlagsy subroutine, and it's lowkey iconic. ✨

✨ SYNOPSIS ✨

Functions/Subroutines

       subroutine dlagsy (n, k, d, a, lda, iseed, work, info)
           DLAGSY

🌸 Function/Subroutine Documentation 🌸

   subroutine dlagsy (integer n, integer k, double precision, dimension( * ) d,
       double precision, dimension( lda, * ) a, integer lda, integer,
       dimension( 4 ) iseed, double precision, dimension( * ) work, integer
       info)
       DLAGSY

💫 Purpose 💫

bestie, DLAGSY generates a real symmetric matrix A by pre- and post-multiplying a real diagonal matrix D with a random orthogonal matrix: A = U*D*U'. The semi-bandwidth may then be reduced to k by additional orthogonal transformations. that's the whole main-character plot. 🦋

🎀 Parameters 🎀

  • N — INTEGER. The order of the matrix A. N >= 0.
  • K — INTEGER. The number of nonzero subdiagonals within the band of A. 0 <= K <= N-1.
  • D — DOUBLE PRECISION array, dimension (N). The diagonal elements of the diagonal matrix D.
  • A — DOUBLE PRECISION array, dimension (LDA,N). The generated n by n symmetric matrix A (the full matrix is stored).
  • LDA — INTEGER. The leading dimension of the array A. LDA >= N.
  • ISEED — INTEGER array, dimension (4). On entry, the seed of the random number generator; the array elements must be between 0 and 4095, and ISEED(4) must be odd. On exit, the seed is updated.
  • WORK — DOUBLE PRECISION array, dimension (2*N).
  • INFO — INTEGER. = 0: successful exit. < 0: if INFO = -i, the i-th argument had an illegal value.

👑 Author 👑

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

Definition at line 100 of file dlagsy.f.

🌈 Author 🌈

Generated automatically by Doxygen for LAPACK from the source code. 🤖✨

okay bestie, that's the whole page — the source/version tea is LAPACK Version 3.12.0, and the file is TESTING/MATGEN/dlagsy.f(3). The footer didn't hand us a separate date line, so we're rolling with the version + file path. mwah 💋🎀

📦 where this page comes from