SRC/spotrf.f(3)

okay bestie, welcome to SRC/spotrf.f(3) from the Library Functions Manual 💅 this is the page for SRC/spotrf.f, and the main character is the spotrf subroutine. She's giving Cholesky factorization energy, and we're obsessed. 🫶

✨ NAME ✨

SRC/spotrf.f — that's the file/page we're on. Lowkey iconic, no cap. 🎀

✨ SYNOPSIS ✨

Functions/Subroutines

here's the lineup, bestie:

subroutine spotrf (uplo, n, a, lda, info)
    SPOTRF

✨ Function/Subroutine Documentation ✨

subroutine spotrf (character uplo, integer n, real, dimension( lda, * ) a,
    integer lda, integer info)
    SPOTRF

💖 Purpose 💖

okay so SPOTRF computes the Cholesky factorization of a real symmetric positive definite matrix A. yes, positive definite is the vibe check here. ✨

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 block version of the algorithm, calling Level 3 BLAS. periodt. 👑

🌸 Parameters 🌸

• UPLO — is CHARACTER*1. = 'U': upper triangle of A is stored; = 'L': lower triangle of A is stored. 💅
• N — is INTEGER. The order of the matrix A. N >= 0. 🦋
• 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 — is INTEGER. The leading dimension of the array A. LDA >= max(1,N). 🌈
• INFO — is INTEGER. = 0: successful exit; < 0: if INFO = -i, the i-th argument had an illegal value; > 0: if INFO = i, the leading principal minor of order i is not positive, and the factorization could not be completed. 💀

👑 Author 👑

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

Definition at line 106 of file spotrf.f. ⭐

✨ Author ✨

Generated automatically by Doxygen for LAPACK from the source code. 💜

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cute little sign-off, bestie: the footer credits LAPACK, Version 3.12.0, and this page, SRC/spotrf.f(3). There's no date in the footer, so no invented date — we keep the facts cute and correct. 🧚💖