ZGETRI(3)

📦 version 3.12.0, in opensuse-leap 16.0

ZGETRI(3) — Library Functions Manual — okay bestie, this is the LAPACK page for inverting a matrix via LU, and it is genuinely iconic 💅✨

💖 NAME

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

That's the source file, bestie 🫶 The routine itself is ZGETRI.

✨ SYNOPSIS

🧚 Functions/Subroutines

subroutine ZGETRI (n, a, lda, ipiv, work, lwork, info)
    ZGETRI

🌸 Function/Subroutine Documentation

subroutine ZGETRI (integer n, complex*16, dimension( lda, * ) a, integer
    lda, integer, dimension( * ) ipiv, complex*16, dimension( * ) work,
    integer lwork, integer info)
    ZGETRI

🎀 Purpose

ZGETRI computes the inverse of a matrix using the LU factorization computed by ZGETRF. No cap 🧚✨

This method inverts U and then computes inv(A) by solving the system inv(A)*L = inv(U) for inv(A). It's giving linear algebra main character energy, fr fr 🔥

🦋 Parameters

N

N is INTEGER — the order of matrix A. Must satisfy N >= 0. 💖

A

A is a COMPLEX*16 array, dimension (LDA,N).

On entry, it holds the factors L and U from the factorization A = P*L*U as computed by ZGETRF.

On exit, if INFO = 0, it's the inverse of the original matrix A. Slay 💅

LDA

LDA is INTEGER — the leading dimension of array A. Must satisfy LDA >= max(1,N).

IPIV

IPIV is an INTEGER array, dimension (N) — the pivot indices from ZGETRF; for 1<=i<=N, row i of the matrix was interchanged with row IPIV(i).

WORK

WORK is a COMPLEX*16 array, dimension (MAX(1,LWORK)).

On exit, if INFO=0, then WORK(1) returns the optimal LWORK. ✨

LWORK

LWORK is INTEGER — the dimension of array WORK. Must satisfy LWORK >= max(1,N). For optimal performance, LWORK >= N*NB, where NB is the optimal blocksize returned by ILAENV.

If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA. Lowkey important 🫶

INFO

INFO is INTEGER:

  • = 0: successful exit
  • < 0: if INFO = -i, the i-th argument had an illegal value
  • > 0: if INFO = i, U(i,i) is exactly zero; 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 113 of file zgetri.f.

💫 Author

Generated automatically by Doxygen for LAPACK from the source code. Automation ate, honestly 💅

okay that's the page, bestie 🫶 — this is LAPACK Version 3.12.0, footer path /home/abui...RC/zgetri.f(3), and yes the manual name up top was Library Functions Manual. Bye queen 👑✨💖

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