SRC/sposv.f(3)

💅 SRC/sposv.f 💅

okay bestie, welcome to the Library Functions Manual page for SRC/sposv.f — yes, we're doing Unix manpage but make it make sense. 🫶

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💖 NAME 💖

SRC/sposv.f

✨ SYNOPSIS ✨

🧚 Functions/Subroutines 🧚

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

🦋 Function/Subroutine Documentation 🦋

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

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

🌸 Purpose 🌸

okay so SPOSV computes the solution to a real system of linear equations

A * X = B,

where A is an N-by-N symmetric positive definite matrix and X and B are N-by-NRHS matrices. 💖

The Cholesky decomposition is used to factor A as

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 a lower triangular matrix. The factored form of A is then used to solve the system of equations A * X = B. periodt. ✨

💅 Parameters 💅

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

🌈 Author 🌈

Generated automatically by Doxygen for LAPACK from the source code.

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bye bestie 💖 — this was SRC/sposv.f(3) from the Library Functions Manual, LAPACK Version 3.12.0, generated automatically by Doxygen for LAPACK from the source code. periodt. 🎀