PSPTTRS(l)

💖 NAME 💖

okay bestie, gather round, because PSPTTRS(l) is here to solve a system of linear equations. The exact equation it handles is A(1:N, JA:JA+N-1) * X = B(IB:IB+N-1, 1:NRHS). That's the whole name, no cap, and yes it's giving "I do one job and I do it flawlessly." 💅✨

✨ SYNOPSIS ✨

Here's the exact call, bestie. Copy it character for character, because we do not manifest typos:

       SUBROUTINE PSPTTRS( N, NRHS, D, E, JA, DESCA, B, IB, DESCB, AF, LAF,
                           WORK, LWORK, INFO )

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

           INTEGER         DESCA( * ), DESCB( * )

           REAL            AF( * ), B( * ), D( * ), E( * ), WORK( * )

🎀 PURPOSE 🎀

So like, PSPTTRS solves a system of linear equations.

Where A(1:N, JA:JA+N-1) is the matrix used to produce the factors stored in A(1:N,JA:JA+N-1) and AF by PSPTTRF.

And A(1:N, JA:JA+N-1) is an N-by-N real tridiagonal symmetric positive definite distributed matrix. 🦋

Routine PSPTTRF MUST be called first. Not "maybe," not "if you feel like it" — MUST. Periodt. 💀

okay that's the whole page, bestie. It's LAPACK version 1.5, dated 12 May 1997, and the manual is PSPTTRS(l). Go solve those systems, mwah 💋✨