PCDTTRF(3) ScaLAPACK routine of NEC Numeric Library Collection PCDTTRF(3) NAME PCDTTRF - compute a LU factorization of an N-by-N complex tridiagonal diagonally dominant-like distributed matrix A(1:N, JA:JA+N-1) SYNOPSIS SUBROUTINE PCDTTRF( N, DL, D, DU, JA, DESCA, AF, LAF, WORK, LWORK, INFO ) INTEGER INFO, JA, LAF, LWORK, N INTEGER DESCA( * ) COMPLEX AF( * ), D( * ), DL( * ), DU( * ), WORK( * ) PURPOSE PCDTTRF computes a LU factorization of an N-by-N complex tridiagonal diagonally dominant-like distributed matrix A(1:N, JA:JA+N-1). Reorder- ing is used to increase parallelism in the factorization. This reordering results in factors that are DIFFERENT from those produced by equivalent sequential codes. These factors cannot be used directly by users; however, they can be used in subsequent calls to PCDTTRS to solve linear systems. The factorization has the form P A(1:N, JA:JA+N-1) P^T = L U where U is a tridiagonal upper triangular matrix and L is tridiagonal lower triangular, and P is a permutation matrix. ScaLAPACK routine 31 October 2017 PCDTTRF(3)