/home/abui...RC/sstev.f(3)

🌸 NAME 🌸

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

This is the Library Functions Manual page for that source file, and the page path is /home/abui...RC/sstev.f(3). Bestie, it’s a LAPACK routine page. 💅

✨ SYNOPSIS ✨

🦋 Functions/Subroutines 🦋

subroutine SSTEV (jobz, n, d, e, z, ldz, work, info)

SSTEV computes the eigenvalues and, optionally, the left and/or right eigenvectors for OTHER matrices. 👑

💖 Function/Subroutine Documentation 💖

🎀 subroutine SSTEV 🎀

subroutine SSTEV (character jobz, integer n, real, dimension( * ) d, real,
    dimension( * ) e, real, dimension( ldz, * ) z, integer ldz, real,
    dimension( * ) work, integer info)

SSTEV computes the eigenvalues and, optionally, the left and/or right eigenvectors for OTHER matrices. That’s the whole main-character summary, periodt. ✨

🌈 Purpose 🌈

The Purpose block says, literally:

!> SSTEV computes all eigenvalues and, optionally, eigenvectors of a
!> real symmetric tridiagonal matrix A.
!>

🍓 Parameters 🍓

• JOBZ — JOBZ is CHARACTER*1. It’s the selector: = 'N': Compute eigenvalues only; = 'V': Compute eigenvalues and eigenvectors.
• N — N is INTEGER. The order of the matrix. N >= 0.
• D — D is REAL array, dimension (N). On entry, the n diagonal elements of the tridiagonal matrix A. On exit, if INFO = 0, the eigenvalues in ascending order.
• E — E is REAL array, dimension (N-1). On entry, the (n-1) subdiagonal elements of the tridiagonal matrix A, stored in elements 1 to N-1 of E. On exit, the contents of E are destroyed.

⚠️ Warning: E gets destroyed on exit. Not a drill, bestie. 💀

• Z — Z is REAL array, dimension (LDZ, N). If JOBZ = 'V', then if INFO = 0, Z contains the orthonormal eigenvectors of the matrix A, with the i-th column of Z holding the eigenvector associated with D(i). If JOBZ = 'N', then Z is not referenced.
• LDZ — LDZ is INTEGER. The leading dimension of the array Z. LDZ >= 1, and if JOBZ = 'V', LDZ >= max(1,N).
• WORK — WORK is REAL array, dimension (max(1,2*N-2)). If JOBZ = 'N', WORK is not referenced.
• INFO — INFO is INTEGER. The status tea: = 0: successful exit; < 0: if INFO = -i, the i-th argument had an illegal value; > 0: if INFO = i, the algorithm failed to converge; i off-diagonal elements of E did not converge to zero.

👑 Author 👑

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

Definition at line 115 of file sstev.f.

👑 Author 👑

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xoxo, LAPACK Version 3.12.0 — footer source/page: /home/abui...RC/sstev.f(3) 💖✨