SRC/zhbev.f(3)

📦
version 3.12.1 · 7 versions
, in arch rolling

💖 NAME

SRC/zhbev.f — bestie, this is the Library Functions Manual page for that file, and it's lowkey iconic. ✨

✨ SYNOPSIS

🫶 Functions/Subroutines

subroutine zhbev (jobz, uplo, n, kd, ab, ldab, w, z, ldz, work, rwork,
    info)
     ZHBEV computes the eigenvalues and, optionally, the left and/or
    right eigenvectors for OTHER matrices

ZHBEV computes the eigenvalues and, optionally, the left and/or right eigenvectors for OTHER matrices. 💅

🌸 Function/Subroutine Documentation

🎀 subroutine zhbev

subroutine zhbev (character jobz, character uplo, integer n, integer kd,
    complex*16, dimension( ldab, * ) ab, integer ldab, double precision,
    dimension( * ) w, complex*16, dimension( ldz, * ) z, integer ldz,
    complex*16, dimension( * ) work, double precision, dimension( * ) rwork,
    integer info)

ZHBEV computes the eigenvalues and, optionally, the left and/or right eigenvectors for OTHER matrices. fr fr, that's the whole vibe. 🦋

🎀 Purpose

ZHBEV computes all the eigenvalues and, optionally, eigenvectors of a complex Hermitian band matrix A. slay. 👑

💅 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.

💫 KD

KD is INTEGER.

The number of superdiagonals of the matrix A if UPLO = 'U', or the number of subdiagonals if UPLO = 'L'. KD >= 0.

💫 AB

AB is COMPLEX*16 array, dimension (LDAB, N).

On entry, the upper or lower triangle of the Hermitian band matrix A, stored in the first KD+1 rows of the array. The j-th column of A is stored in the j-th column of the array AB as follows:

  • if UPLO = 'U', AB(kd+1+i-j,j) = A(i,j) for max(1,j-kd)<=i<=j;
  • if UPLO = 'L', AB(1+i-j,j) = A(i,j) for j<=i<=min(n,j+kd).

On exit, AB is overwritten by values generated during the reduction to tridiagonal form. If UPLO = 'U', the first superdiagonal and the diagonal of the tridiagonal matrix T are returned in rows KD and KD+1 of AB, and if UPLO = 'L', the diagonal and first subdiagonal of T are returned in the first two rows of AB.

💫 LDAB

LDAB is INTEGER.

The leading dimension of the array AB. LDAB >= KD + 1.

💫 W

W is DOUBLE PRECISION array, dimension (N).

If INFO = 0, the eigenvalues in ascending order.

💫 Z

Z is COMPLEX*16 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 COMPLEX*16 array, dimension (N).

💫 RWORK

RWORK is DOUBLE PRECISION array, dimension (max(1,3*N-2)).

💫 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 150 of file zhbev.f.

🌈 Author

Generated automatically by Doxygen for LAPACK from the source code. 🫶

okay bye bestie 💖 this lil page comes from SRC/zhbev.f(3), and the library is LAPACK Version 3.12.0. mwah! 🎀✨

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