dpotrf.f(3)

🌸 NAME 🌸

Okay bestie, this is the LAPACK manual page for dpotrf.f(3) — and it’s giving “top-looking block version of the algorithm, calling Level 3 BLAS” energy. 💅 No cap.

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✨ SYNOPSIS ✨

🧸 Functions/Subroutines

• subroutine dpotrf (UPLO, N, A, LDA, INFO) — DPOTRF VARIANT: top-looking block version of the algorithm, calling Level 3 BLAS. 🦋

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💫 Function/Subroutine Documentation 💫

subroutine dpotrf (character UPLO, integer N, double precision, dimension(
       lda, * ) A, integer LDA, integer INFO)

DPOTRF VARIANT: top-looking block version of the algorithm, calling Level 3 BLAS. Periodt. 💖

🎯 Purpose

DPOTRF 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 top-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 DOUBLE PRECISION 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/TOP/dpotrf.f.

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🫶 Author

Generated automatically by Doxygen for LAPACK from the source code.

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And that’s the whole vibe check, bestie — LAPACK manual page dpotrf.f(3), Version 3.8.0, dated Tue Nov 14 2017. Slay responsibly. 💋✨🎀