Welcome to the Exelis VIS product documentation center! Here you will find reference guides, help documents, and product libraries. Discover the products including ENVI, IDL, and ENVI LiDAR, and solutions developed by Exelis VIS at www.exelisvis.com.


LUDC

LUDC

The LUDC procedure replaces an n by n array, A, with the LU decomposition of a row-wise permutation of itself.

LUDC is based on the routine ludcmp described in section 2.3 of Numerical Recipes in C: The Art of Scientific Computing (Second Edition), published by Cambridge University Press, and is used by permission.

Note: If you are working with complex inputs, use the LA_LUDC procedure instead.

Examples


See the description of LUSOL for an example using this procedure.

Syntax


LUDC, A, Index [, /COLUMN] [, /DOUBLE] [, INTERCHANGES=variable]

Arguments


A

An n by n array of any type except string. Upon output, A is replaced with its LU decomposition.

Index

An output vector that records the row permutations which occurred as a result of partial pivoting.

Keywords


COLUMN

Set this keyword if the input array A is in column-major format (composed of column vectors) rather than in row-major format (composed of row vectors).

DOUBLE

Set this keyword to force the computation to be done in double-precision arithmetic.

INTERCHANGES

An output variable that is set to positive 1 if the number of row interchanges was even, or to negative 1 if the number of interchanges was odd.

Version History


4.0

Introduced

See Also


LA_LUDC, LUSOL



Comments


This page has no comments yet. Be the first one!

© 2013 Exelis Visual Information Solutions