/home/abui...RC/cposv.f(3)

okay so this is the manual page for cposv.f(3), and yes bestie, it’s from the Library Functions Manual — we’re keeping every detail, just with way more sparkle. 🫶

---

💖 NAME 💖

This page is literally about this file path:

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/cposv.f

---

✨ SYNOPSIS ✨

🦋 Functions/Subroutines 🦋

• subroutine CPOSV (uplo, n, nrhs, a, lda, b, ldb, info) — CPOSV computes the solution to system of linear equations A * X = B for PO matrices

---

🫶 Function/Subroutine Documentation 🫶

Main character subroutine incoming:

subroutine CPOSV (character uplo, integer n, integer nrhs, complex,
     dimension( lda, * ) a, integer lda, complex, dimension( ldb, * ) b,
     integer ldb, integer info)

CPOSV computes the solution to system of linear equations A * X = B for PO matrices.

🌸 Purpose 🌸

Here’s the tea: CPOSV computes the solution to a complex system of linear equations

A * X = B,

where A is an N-by-N Hermitian positive definite matrix and X and B are N-by-NRHS matrices. No cap.

The Cholesky decomposition is used to factor A as

A = U**H* U,  if UPLO = 'U', or
A = L * L**H,  if UPLO = 'L',

where U is an upper triangular matrix and L is a lower triangular matrix. Then the factored form of A is used to solve the system of equations

A * X = B.

🎀 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 number of linear equations, i.e., the order of the matrix A. N >= 0.
• NRHS — NRHS is INTEGER; the number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0.
• A — A is COMPLEX array, dimension (LDA,N). On entry, the Hermitian 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**H*U or A = L*L**H.
• LDA — LDA is INTEGER; the leading dimension of the array A. LDA >= max(1,N).
• B — B is COMPLEX array, dimension (LDB,NRHS). On entry, the N-by-NRHS right hand side matrix B. On exit, if INFO = 0, the N-by-NRHS solution matrix X.
• LDB — LDB is INTEGER; the leading dimension of the array B. LDB >= 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 principal minor of order i of A is not positive, so the factorization could not be completed, and the solution has not been computed.

lowkey important: when INFO > 0, the factorization could not be completed and the solution has not been computed. 💀

👑 Author 👑

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

Definition at line 129 of file cposv.f.

---

💜 Author 💜

Generated automatically by Doxygen for LAPACK from the source code.

---

okay that’s the whole page, bestie — cute sign-off time: LAPACK Version 3.12.0 and the footer path /home/abui...RC/cposv.f(3). mwah 💋✨