SRC/zgetri.f(3)

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version 3.12.1 · 4 versions
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🦋 SRC/zgetri.f 🦋

Welcome to the Library Functions Manual, bestie — this is literally the SRC/zgetri.f entry, and it's giving “complex matrix inverse” main-character energy. 💅

✨ SYNOPSIS ✨

🎀 Functions/Subroutines 🎀

  • subroutine zgetri (n, a, lda, ipiv, work, lwork, info) — the whole callable vibe. The routine's name is ZGETRI, no cap.

🌸 Function/Subroutine Documentation 🌸

Here's the full signature, exactly as the page serves it:

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

ZGETRI

She's iconic, she's precise, she's ready to invert. 🫶

🧚 Purpose 🧚

So the glow-up is: ZGETRI computes the inverse of a matrix using the LU factorization computed by ZGETRF. This method inverts U first, then computes inv(A) by solving the system inv(A)*L = inv(U) for inv(A). Literally solving for the inverse, periodt. 💖

🎀 Parameters 🎀

  • N — INTEGER. The order of the matrix A, and N >= 0.
  • 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.
  • LDA — INTEGER. The leading dimension of the array A, with LDA >= max(1,N).
  • IPIV — INTEGER array, dimension (N). These are the pivot indices from ZGETRF; for 1<=i<=N, row i of the matrix was interchanged with row IPIV(i).
  • WORK — COMPLEX*16 array, dimension (MAX(1,LWORK)). On exit, if INFO=0, then WORK(1) returns the optimal LWORK.
  • LWORK — INTEGER. The dimension of the array WORK. 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.
  • INFO — 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.

💖 And that's the page, bestie: LAPACK, Version 3.12.0, SRC/zgetri.f(3), with no separate date printed in this footer. Periodt. 💖

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