If the reader identifies problems in the software, he or she is encouraged to report them to the authors ( fpfontan@tsc.uvigo.es or pmarino@uvigo.es ) so that we can make the required updates or provide solutions. Readers can contact the above email addresses so that we can supply them with the ftp address (or alternative means) for downloading the software. We have used version 7 of Matlab, and the programs may not work on earlier versions. Matlab's signal processing toolbox should also be available for a proper operation of the programs supplied.