Linear Systems Solver Service Example

This example shows you how to create a linear systems solver Web service. An example demonstration client code is given as well. The service uses dynamic arrays for vectors and matrices. Vectors and matrices are exchanged in SOAP as partially transmitted arrays of double. This supports a simple form of matrix sparsity (however, the linear systems solver algorithm is a dense matrix solver). The service returns partially transmitted arrays by eliminating initial and trailing zeros in vectors and matrices.

The Web service implements the following remote methods:

ludcmp: LU decomposition of a matrix
lubksb: backsubstitution for LU decomposition
lusol: LU-decomposition-based linear system solver
lusols: LU-decomposition-based solver of multiple linear systems
luinv: LU-decomposition-based matrix inversion
ludet: LU-decomposition-based matrix determinant

Generated WSDL service description.

Step 1: Write the Main Program

We wrote a linear systems solver service for you: click here and select "File - Save As" from your browser's menu.

You also need a C++ library with vector and matrix classes: click here.

To test your linear systems solver service, get a demonstration client source code: click here.

Step 2: Generate the SOAP Stub Routines

The input to the SOAP C++ stub and skeleton compiler is a specification of the names of the SOAP methods and the data structures given as C/C++ declarations. You can get this header file specification here. This header file is used to compile the linear systems solver service and demonstration client.

Use the SOAP C/C++ stub and skeleton compiler to process the header file:

soapcpp lu.h

Step 3: Compiling Your Service App

Compile the service sources. For example, in Linux the command to compile would be:

g++ -o luserver.cgi luserver.cpp lumat.cpp soapC.cpp soapServer.cpp stdsoap2.cpp

Deploy the luserver.cgi executable as a CGI application in your Web server.

Step 4: Compiling Your Demonstration Client App

Change the endpoint URL in the luclient.cpp source to your endpoint URL for this service (the URL of your CGI application).

Compile the client sources. For example, in Linux the command to compile would be:

g++ -o luclient luclient.cpp lumat.cpp soapC.cpp soapClient.cpp stdsoap2.cpp

Step 5: Try it Out

Execute the command "luclient".

Step 6: Alternative: Stand-Alone Service App

Compile the service as indicated in Step 3. Execute the command:

luserver.cgi "mymachine.mydomain.com" 18080 &

where "mymachine.mydomain.com" refers to the machine on which the service is executed. Note that the service can run in the background.

Change the endpoint URL of the demonstration client luclient.cpp to "mymachine.mydomain.com:18080" and recompile the client sources.

Execute the command "luclient", which will now be served by the stand-alone service via your intranet directly over sockets.