# LINEAR_SOLVE_DISTRIBUTED Solution of a Distributed Linear System

LINEAR_SOLVE_DISTRIBUTED is a MATLAB program which solves a linear system A*x=b using MATLAB's spmd facility, so that the matrix A is "distributed" across multiple MATLAB workers.

This example only illustrates the use of spmd, but does not really explain much about what's going on.

We use a number of MATLAB workers, LAB_NUM.

We declare a matrix A of size N by N, but we use the codistributor() function, so that A is distributed among the workers, which each get an N by (N/LAB_NUM) portion of the matrix.

With a given right hand side b, MATLAB's backslash function is able to solve the linear system A*x=b, even though the matrix is distributed.

The result, x is compared to the exact solution (a vector of 1's) and the norm of the error is returned.

### Languages:

LINEAR_SOLVE_DISTRIBUTED is available in a MATLAB version.

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### Reference:

The User's Guide for the Parallel Computing Toolbox is available at http://www.mathworks.com/access/helpdesk/help/pdf_doc/distcomp/distcomp.pdf

1. Gaurav Sharma, Jos Martin,
MATLAB: A Language for Parallel Computing,
International Journal of Parallel Programming,
Volume 37, Number 1, pages 3-36, February 2009.

### Source Code:

You can go up one level to the MATLAB source codes.

Last revised on 23 April 2009.