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

🌸 NAME 🌸

okay so this page is /home/abui...RC/chpgv.f(3) from the Library Functions Manual, and the actual file it's hyping up is /home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/chpgv.f. That's the whole name section, bestie — a path and a dream ✨.

🦋 SYNOPSIS 🦋

   Functions/Subroutines
       subroutine CHPGV (itype, jobz, uplo, n, ap, bp, w, z, ldz, work, rwork,
           info)
           CHPGV

✨ Function/Subroutine Documentation ✨

🌈 subroutine CHPGV 🌈

   subroutine CHPGV (integer itype, character jobz, character uplo, integer n,
       complex, dimension( * ) ap, complex, dimension( * ) bp, real, dimension(
       * ) w, complex, dimension( ldz, * ) z, integer ldz, complex, dimension(
       * ) work, real, dimension( * ) rwork, integer info)
       CHPGV

💖 Purpose 💖

okay so CHPGV computes all the eigenvalues and, optionally, the eigenvectors of a complex generalized Hermitian-definite eigenproblem. The forms are:

A*x=(lambda)*B*x,  A*Bx=(lambda)*x,  or B*A*x=(lambda)*x.

Here A and B are assumed to be Hermitian, stored in packed format, and B is also positive definite. slay 💅

💅 Parameters 💅

Every single one, no skips, periodt:

🌟 ITYPE 🌟

ITYPE is INTEGER. It specifies the problem type to be solved:

• = 1: A*x = (lambda)*B*x
• = 2: A*B*x = (lambda)*x
• = 3: B*A*x = (lambda)*x

🦋 JOBZ 🦋

JOBZ is CHARACTER*1:

• = 'N': Compute eigenvalues only;
• = 'V': Compute eigenvalues and eigenvectors.

🌸 UPLO 🌸

UPLO is CHARACTER*1:

• = 'U': Upper triangles of A and B are stored;
• = 'L': Lower triangles of A and B are stored.

🎀 N 🎀

N is INTEGER. The order of the matrices A and B. N >= 0.

⭐ AP ⭐

AP is COMPLEX array, dimension (N*(N+1)/2). On entry, the upper or lower triangle of the Hermitian 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, the contents of AP are destroyed. 💀

💜 BP 💜

BP is COMPLEX array, dimension (N*(N+1)/2). On entry, the upper or lower triangle of the Hermitian matrix B, packed columnwise in a linear array. The j-th column of B is stored in the array BP as follows:

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

On exit, the triangular factor U or L from the Cholesky factorization B = U**H*U or B = L*L**H, in the same storage format as B.

🍓 W 🍓

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

🧚 Z 🧚

Z is COMPLEX array, dimension (LDZ, N). If JOBZ = 'V', then if INFO = 0, Z contains the matrix Z of eigenvectors. The eigenvectors are normalized as follows:

• if ITYPE = 1 or 2, Z**H*B*Z = I;
• if ITYPE = 3, Z**H*inv(B)*Z = 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 array, dimension (max(1, 2*N-1)).

🌸 RWORK 🌸

RWORK is REAL 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: CPPTRF or CHPEV returned an error code:
  • <= N: if INFO = i, CHPEV failed to converge; i off-diagonal elements of an intermediate tridiagonal form did not convergeto zero;
  • > N: if INFO = N + i, for 1 <= i <= n, then the leading principal minor of order i of B is not positive. The factorization of B could not be completed and no eigenvalues or eigenvectors were computed.

✨ Author ✨

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

📌 Definition at line 163 of file chpgv.f 📌

Definition at line 163 of file chpgv.f.

🎀 Author 🎀

Generated automatically by Doxygen for LAPACK from the source code.

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mwah 💋 that's the whole glow-up. This page is from LAPACK Version 3.12.0, path /home/abui...RC/chpgv.f(3). Bye bestie, go compute those eigenvalues 🫶