SRC/ztrtri.f(3)

📦
version 3.12.1 · 4 versions
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Bestie, welcome to SRC/ztrtri.f — this page lives in the Library Functions Manual, and it's literally the ZTRTRI moment. ✨

💖 NAME

SRC/ztrtri.f — that's the page, bestie. It's all about ZTRTRI.

✨ SYNOPSIS

🎀 Functions/Subroutines

       subroutine ztrtri (uplo, diag, n, a, lda, info)
           ZTRTRI

🧚 Function/Subroutine Documentation

   subroutine ztrtri (character uplo, character diag, integer n, complex*16,
       dimension( lda, * ) a, integer lda, integer info)
       ZTRTRI

💫 Purpose

Ok so ZTRTRI computes the inverse of a complex upper or lower triangular matrix A. No cap. And bestie, this is the Level 3 BLAS version of the algorithm. 🫶

🎀 Parameters

🌸 UPLO

UPLO is CHARACTER*1, and it tells us the shape vibe:

  • = 'U': A is upper triangular;
  • = 'L': A is lower triangular.

🦋 DIAG

DIAG is CHARACTER*1, and it says whether the diagonal is unit or not:

  • = 'N': A is non-unit triangular;
  • = 'U': A is unit triangular.

⭐ N

N is INTEGER. It's the order of the matrix A, and N >= 0.

👑 A

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

On entry, it's the triangular matrix A. If UPLO = 'U', the leading N-by-N upper triangular part of the array A contains the upper triangular matrix, and the strictly lower triangular part of A is not referenced. If UPLO = 'L', the leading N-by-N lower triangular part of the array A contains the lower triangular matrix, and the strictly upper triangular part of A is not referenced. If DIAG = 'U', the diagonal elements of A are also not referenced and are assumed to be 1.

On exit, it holds the (triangular) inverse of the original matrix, in the same storage format. Obsessed with consistency. 💅

🍓 LDA

LDA is INTEGER. It's the leading dimension of the array A, and it must be LDA >= max(1,N).

🔥 INFO

INFO is INTEGER. The exit tea:

  • = 0: successful exit
  • < 0: if INFO = -i, the i-th argument had an illegal value
  • > 0: if INFO = i, A(i,i) is exactly zero. The triangular matrix is singular and its inverse can not be computed.

👑 Author

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

Definition at line 108 of file ztrtri.f.

👑 Author

Generated automatically by Doxygen for LAPACK from the source code.

Ok bye bestie — footer tea is LAPACK, Version 3.12.0, and SRC/ztrtri.f(3). Stay triangular, stay iconic. 🌈💅✨

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