---
name: "pdpbtrsv"
section: "3"
platform: "linux"
package: "scalapack-doc"
version: "1.5-11"
release: "Debian 11 (Bullseye)"
platforms: ["linux"]
url: "https://new.carta.tech/pdpbtrsv"
---

# pdpbtrsv(3)

solve a banded triangular system of linear equations A(1:N, JA:JA+N-1) \* X = B(IB:IB+N-1, 1:NRHS)

## NAME

PDPBTRSV - solve a banded triangular system of linear equations   A(1:N, JA:JA+N-1) \* X = B(IB:IB+N-1, 1:NRHS)

## SYNOPSIS

- SUBROUTINE PDPBTRSV(

  UPLO, TRANS, N, BW, NRHS, A, JA, DESCA, B, IB, DESCB, AF, LAF, WORK, LWORK, INFO )

- CHARACTER

  TRANS, UPLO

- INTEGER

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

- INTEGER

  DESCA( \* ), DESCB( \* )

- DOUBLE

  PRECISION A( \* ), AF( \* ), B( \* ), WORK( \* )

## PURPOSE

PDPBTRSV solves a banded triangular system of linear equations\
                                or\
\
                     A(1:N, JA:JA+N-1)^T \* X = B(IB:IB+N-1, 1:NRHS)

where A(1:N, JA:JA+N-1) is a banded\
 triangular matrix factor produced by the\
 Cholesky factorization code PDPBTRF\
 and is stored in A(1:N,JA:JA+N-1) and AF.\
 The matrix stored in A(1:N, JA:JA+N-1) is either\
 upper or lower triangular according to UPLO,\
 and the choice of solving A(1:N, JA:JA+N-1) or A(1:N, JA:JA+N-1)^T is dictated by the user by the parameter TRANS.\

Routine PDPBTRF MUST be called first.\