spotrf.f(3)

💖 NAME 💖

spotrf.f — hiii bestie, welcome to the LAPACK manual page for spotrf.f. This is the group chat where Cholesky factorization gets its moment 💅.

✨ SYNOPSIS ✨

🧚 Functions/Subroutines 🧚

• subroutine spotrf (UPLO, N, A, LDA, INFO) — SPOTRF VARIANT: right looking block version of the algorithm, calling Level 3 BLAS.

🦋 Function/Subroutine Documentation 🦋

subroutine spotrf (character UPLO, integer N, real, dimension( lda, * ) A,
    integer LDA, integer INFO)

SPOTRF VARIANT: right looking block version of the algorithm, calling Level 3 BLAS. That's literally the intro, and now we get into the purpose, bestie.

🎀 Purpose 🎀

SPOTRF computes the Cholesky factorization of a real symmetric positive definite matrix A.

The factorization has the form

   A = U**T * U,  if UPLO = 'U', or
   A = L  * L**T,  if UPLO = 'L',

where U is an upper triangular matrix and L is lower triangular.

This is the right looking block version of the algorithm, calling Level 3 BLAS.

🌸 Parameters 🌸

• UPLO — UPLO is CHARACTER*1. 'U': Upper triangle of A is stored; 'L': Lower triangle of A is stored.
• N — N is INTEGER. The order of the matrix A. N >= 0.
• A — A is REAL array, dimension (LDA,N). On entry, the symmetric matrix A. If UPLO = 'U', the leading N-by-N upper triangular part of A contains the upper triangular part of the matrix A, and the strictly lower triangular part of A is not referenced. If UPLO = 'L', the leading N-by-N lower triangular part of A contains the lower triangular part of the matrix A, and the strictly upper triangular part of A is not referenced. On exit, if INFO = 0, the factor U or L from the Cholesky factorization A = U**T*U or A = L*L**T.
• LDA — LDA is INTEGER. The leading dimension of the array A. LDA >= max(1,N).
• INFO — INFO is INTEGER.
  • = 0: successful exit 🎉
  • < 0: if INFO = -i, the i-th argument had an illegal value 🙈
  • > 0: if INFO = i, the leading minor of order i is not positive definite, and the factorization could not be completed 💀

👑 Author 👑

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

📅 Date 📅

December 2016

Definition at line 102 of file VARIANTS/cholesky/RL/spotrf.f.

🌟 Author 🌟

Generated automatically by Doxygen for LAPACK from the source code.

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okay bye ily bestie 💖 this page is from LAPACK Version 3.8.0, dated Tue Nov 14 2017, and it's literally spotrf.f(3) — slay and stay positive definite 🫶✨