SRC/ssterf.f(3)

📦
version 3.12.1 · 7 versions
, in arch rolling

✨ NAME ✨

SRC/ssterf.f — from the Library Functions Manual, bestie 💅 (manual name folded in right here, as promised).

🦋 SYNOPSIS 🦋

Functions/Subroutines

   Functions/Subroutines
       subroutine ssterf (n, d, e, info)
           SSTERF

💖 Function/Subroutine Documentation 💖

   subroutine ssterf (integer n, real, dimension( * ) d, real, dimension( * )
       e, integer info)
       SSTERF

Purpose 🎀

okay so SSTERF computes all eigenvalues of a symmetric tridiagonal matrix using the Pal-Walker-Kahan variant of the QL or QR algorithm. that's the whole purpose, and it ate 🔥

Parameters 🌸

N

N is INTEGER. it's the order of the matrix. N >= 0. periodt.

D

D is REAL array, dimension (N).

On entry, the n diagonal elements of the tridiagonal matrix.

On exit, if INFO = 0, the eigenvalues in ascending order. slay 💖

E

E is REAL array, dimension (N-1).

On entry, the (n-1) subdiagonal elements of the tridiagonal matrix.

On exit, E has been destroyed. not me being dramatic, that's literally what the page says 😭💀

INFO

INFO is INTEGER.

  • = 0: successful exit ✨
  • < 0: if INFO = -i, the i-th argument had an illegal value 🙈
  • > 0: the algorithm failed to find all of the eigenvalues in a total of 30*N iterations; if INFO = i, then i elements of E have not converged to zero 💅

Author 🫶

the academic icons behind this one:

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

Definition at line 85 of file ssterf.f. 📍

yup, that's where it lives: Definition at line 85 of file ssterf.f.

Author 🤖

Generated automatically by Doxygen for LAPACK from the source code.

okay bestie that's the whole page 💖 shoutout to LAPACK Version 3.12.0 and the source SRC/ssterf.f(3) — generated automatically by Doxygen for LAPACK from the source code. periodt ✨💅

📦 where this page comes from