DTRID(3S)DTRID(3S)NAMEDTRID - compute the solution to a real system of linear equations A*x =
b, where A is an N-by-N tridiagonal matrix, and x and b are vectors of
length N
SYNOPSIS
SUBROUTINE DTRID( N, DL, D, DU, B )
INTEGER N
DOUBLE PRECISION
DL( * ), D( * ), DU( * ), B( * )
IMPLEMENTATION
These routines are part of the SCSL Scientific Library and can be loaded
using either the -lscs or the -lscs_mp option. The -lscs_mp option
directs the linker to use the multi-processor version of the library.
When linking to SCSL with -lscs or -lscs_mp, the default integer size is
4 bytes (32 bits). Another version of SCSL is available in which integers
are 8 bytes (64 bits). This version allows the user access to larger
memory sizes and helps when porting legacy Cray codes. It can be loaded
by using the -lscs_i8 option or the -lscs_i8_mp option. A program may use
only one of the two versions; 4-byte integer and 8-byte integer library
calls cannot be mixed.
PURPOSEDTRID computes the solution of a tridiagonal system of linear equations
A*x = b using a "burn-at-both-ends" algorithm. NO PIVOTING FOR STABILITY
IS DONE.
ARGUMENTS
N (input) INTEGER
The order of the matrix A. N >= 0.
DL (input/output) DOUBLE PRECISION array, dimension (N-1)
On entry, the (N-1) subdiagonal elements of the tridiagonal
matrix A. On exit, DL is overwritten.
D (input/output) DOUBLE PRECISION array, dimension (N)
On entry, the N diagonal elements of the tridiagonal matrix A.
On exit, D is overwritten.
DU (input/output) DOUBLE PRECISION array, dimension (N-1)
On entry, the (N-1) superdiagonal elements of the tridiagonal
matrix A. On exit, DU is overwritten.
B (input/output) DOUBLE PRECISION array, dimension (N)
On entry, the N-element right hand side vector b. On exit, the
N-element solution vector x.
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DTRID(3S)DTRID(3S)SEE ALSOINTRO_LAPACK(3S), INTRO_SCSL(3S)
This man page is available only online.
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