PDPBSV(l)

💖 NAME 💖

PDPBSV — bestie, it solves a system of linear equations:

A(1:N, JA:JA+N-1) * X = B(IB:IB+N-1, 1:NRHS)

✨ SYNOPSIS ✨

SUBROUTINE PDPBSV( UPLO, N, BW, NRHS, A, JA, DESCA, B, IB, DESCB, WORK,
                   LWORK, INFO )

    CHARACTER      UPLO

    INTEGER        BW, IB, INFO, JA, LWORK, N, NRHS

    INTEGER        DESCA( * ), DESCB( * )

    DOUBLE         PRECISION A( * ), B( * ), WORK( * )

🎀 PURPOSE 🎀

okay so PDPBSV solves a system of linear equations

A(1:N, JA:JA+N-1) * X = B(IB:IB+N-1, 1:NRHS)

where A(1:N, JA:JA+N-1) is an N-by-N real banded symmetric positive definite distributed matrix with bandwidth BW. 💅

Cholesky factorization is used to factor a reordering of the matrix into L L'. 🦋

lowkey important: see PDPBTRF and PDPBTRS for details, bestie. 🫶

and that's the whole thing, no cap — this page is LAPACK routine version 1.5, dated 12 May 1997. iconic behavior honestly, periodt. 💖✨🎀