ZSPTRI(3)

📦 version 3.12.0, in opensuse-leap 16.0

🎀 NAME 🎀

Manual: ZSPTRI(3) — Library Functions Manual.

Source file: /home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/zsptri.f

✨ SYNOPSIS ✨

🧚 Functions/Subroutines 🧚

  • subroutine ZSPTRI (uplo, n, ap, ipiv, work, info) — bestie, this is the whole vibe. ZSPTRI.

💅 Function/Subroutine Documentation 💅

subroutine ZSPTRI (character uplo, integer n, complex*16, dimension( * ) ap,
    integer, dimension( * ) ipiv, complex*16, dimension( * ) work, integer
    info)

ZSPTRI

🎯 Purpose

okay so ZSPTRI computes the inverse of a complex symmetric indefinite matrix A in packed storage using the factorization A = U*D*U**T or A = L*D*L**T computed by ZSPTRF. That's the whole main-character job, and she ate. 💅

🌈 Parameters 🌈

🦋 UPLO

UPLO is CHARACTER*1. It specifies whether the details of the factorization are stored as an upper or lower triangular matrix.

= 'U':  Upper triangular, form is A = U*D*U**T;
= 'L':  Lower triangular, form is A = L*D*L**T.

🍓 N

N is INTEGER. It's the order of the matrix A. No cap: N >= 0.

🌸 AP

AP is COMPLEX*16 array, dimension (N*(N+1)/2).

On entry, it's the block diagonal matrix D and the multipliers used to obtain the factor U or L as computed by ZSPTRF, stored as a packed triangular matrix. 🫶

On exit, if INFO = 0, it's the (symmetric) inverse of the original matrix, stored as a packed triangular matrix. The j-th column of inv(A) is stored in the array AP as follows:

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

🐚 IPIV

IPIV is INTEGER array, dimension (N). It holds the details of the interchanges and the block structure of D as determined by ZSPTRF. iykyk 🔥

🧚 WORK

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

👑

👑 INFO

INFO is INTEGER.

  • = 0: successful exit ✨
  • < 0: if INFO = -i, the i-th argument had an illegal value 🙈
  • > 0: if INFO = i, D(i,i) = 0; the matrix is singular and its inverse could not be computed. 💀

👑 Author 👑

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

Definition at line 108 of file zsptri.f.

💻 Author 💻

Generated automatically by Doxygen for LAPACK from the source code.

Sign-off, bestie: this page is rockin' LAPACK Version 3.12.0, source page /home/abui...RC/zsptri.f(3), and the date slot is giving absolutely nothing — the footer didn't hand us one, so no fake date from me. 😭💜
📦 where this page comes from