SRC/cposv.f(3)

💖 NAME

SRC/cposv.f — okay so bestie, this is the SRC/cposv.f(3) page from the Library Functions Manual, and it's giving very specific LAPACK subroutine energy. 💅

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✨ 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.

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💅 Function/Subroutine Documentation

🌸 subroutine cposv

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. periodt. 🌈

🎀 Purpose

okay so 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, that's the whole assignment. 🫶

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. The factored form of A is then used to solve the system of equations A * X = B. Iconic behavior, honestly. ✨

🍓 Parameters

Every single param is here, bestie. No skips. 👑

• UPLO — CHARACTER*1
  • = 'U': Upper triangle of A is stored;
  • = 'L': Lower triangle of A is stored.
• N — INTEGER
  • The number of linear equations, i.e., the order of the matrix A. N >= 0.
• NRHS — INTEGER
  • The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0.
• A — 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 — INTEGER
  • The leading dimension of the array A. LDA >= max(1,N).
• B — 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 — INTEGER
  • The leading dimension of the array B. LDB >= max(1,N).
• INFO — 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.

👑 Author

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

Definition at line 129 of file cposv.f.

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🦋 Author

Generated automatically by Doxygen for LAPACK from the source code.

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okay that's the whole page, bestie 💖 — LAPACK Version 3.12.0, SRC/cposv.f(3), and yes, it was generated automatically by Doxygen for LAPACK from the source code. Slay. 🫶