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

👑 NAME 👑

okay so this is dspev.f(3) from the Library Functions Manual — main character energy, no cap. 💅 the NAME path is literally this exact thing:

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

like, that's the whole path, bestie. don't lose it. 🎀

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✨ SYNOPSIS ✨

🫶 Functions/Subroutines

• subroutine DSPEV (jobz, uplo, n, ap, w, z, ldz, work, info) — DSPEV computes the eigenvalues and, optionally, the left and/or right eigenvectors for OTHER matrices.

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🦋 Function/Subroutine Documentation 🦋

💜 subroutine DSPEV

subroutine DSPEV (character jobz, character uplo, integer n, double
     precision, dimension( * ) ap, double precision, dimension( * ) w, double
     precision, dimension( ldz, * ) z, integer ldz, double precision,
     dimension( * ) work, integer info)

DSPEV computes the eigenvalues and, optionally, the left and/or right eigenvectors for OTHER matrices. that's the one-liner, periodt. ✨

🎀 Purpose

lowkey the whole vibe: DSPEV computes all the eigenvalues and, optionally, eigenvectors of a real symmetric matrix A in packed storage. that's it, that's the purpose. 💖

🌸 Parameters

🍓 JOBZ

• JOBZ is CHARACTER*1.
• = 'N': Compute eigenvalues only;
• = 'V': Compute eigenvalues and eigenvectors.

🦋 UPLO

• UPLO is CHARACTER*1.
• = 'U': Upper triangle of A is stored;
• = 'L': Lower triangle of A is stored.

⭐ N

• N is INTEGER.
• The order of the matrix A. N >= 0.

🍓 AP

• AP is DOUBLE PRECISION array, dimension (N*(N+1)/2).
• On entry, the upper or lower triangle of the symmetric matrix A, packed columnwise in a linear array. The j-th column of A is stored in the array AP as follows:

if UPLO = 'U', AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j;
if UPLO = 'L', AP(i + (j-1)*(2*n-j)/2) = A(i,j) for j<=i<=n.

• On exit, AP is overwritten by values generated during the reduction to tridiagonal form. If UPLO = 'U', the diagonal and first superdiagonal of the tridiagonal matrix T overwrite the corresponding elements of A, and if UPLO = 'L', the diagonal and first subdiagonal of T overwrite the corresponding elements of A.

🧚 W

• W is DOUBLE PRECISION array, dimension (N).
• If INFO = 0, the eigenvalues in ascending order.

💜 Z

• Z is DOUBLE PRECISION 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 W(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 DOUBLE PRECISION array, dimension (3*N).

🔥 INFO

• INFO is INTEGER.
• = 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 an intermediate tridiagonal form did not converge to zero.

👑 Author 👑

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

Definition at line 129 of file dspev.f.

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🌈 Author 🌈

Generated automatically by Doxygen for LAPACK from the source code.

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okay bestie, that's the whole page. this source is LAPACK Version 3.12.0, and the footer path is /home/abui...RC/dspev.f(3) — slay, bye 💅✨🦋