/**
* Iterate through the event arguments in the BIF way, which is different than Encog's method.
*
* @param event The event to save.
* @param args The arguments.
* @return True if there is further to iterate.
*/
public static boolean rollArgs(BayesianEvent event, int[] args) {
int currentIndex = event.getParents().size() - 1;
boolean done = false;
boolean eof = false;
if (event.getParents().size() == 0) {
done = true;
eof = true;
}
while (!done) {
int v = (int) args[currentIndex];
v++;
if (v >= event.getParents().get(currentIndex).getChoices().size()) {
args[currentIndex] = 0;
} else {
args[currentIndex] = v;
done = true;
break;
}
currentIndex--;
if (currentIndex < 0) {
done = true;
eof = true;
}
}
return !eof;
}
/**
* Write a Bayesian network to an output stream in BIF format.
*
* @param os The output stream to write to.
* @param network The network to write.
*/
public static void writeBIF(OutputStream os, BayesianNetwork network) {
WriteXML xml = new WriteXML(os);
xml.beginDocument();
xml.addAttribute("VERSION", "0.3");
xml.beginTag("BIF");
xml.beginTag("NETWORK");
xml.addProperty("NAME", "Bayes Network, Generated by Encog");
// write variables
for (BayesianEvent event : network.getEvents()) {
xml.addAttribute("TYPE", "nature");
xml.beginTag("VARIABLE");
xml.addProperty("NAME", event.getLabel());
for (BayesianChoice str : event.getChoices()) {
xml.addProperty("OUTCOME", str.getLabel());
}
xml.endTag();
}
// write relations
for (BayesianEvent event : network.getEvents()) {
xml.beginTag("DEFINITION");
xml.addProperty("FOR", event.getLabel());
for (BayesianEvent parentEvent : event.getParents()) {
xml.addProperty("GIVEN", parentEvent.getLabel());
}
xml.addAttribute("TABLE", generateTable(event));
xml.endTag();
}
xml.endTag();
xml.endTag();
xml.endDocument();
}
/**
* Generate a table, in BIF format.
*
* @param event The event to write.
* @return The string form of the table.
*/
public static String generateTable(BayesianEvent event) {
StringBuilder s = new StringBuilder();
int tableIndex = 0;
int[] args = new int[event.getParents().size()];
do {
for (int result = 0; result < event.getChoices().size(); result++) {
TableLine line = event.getTable().findLine(result, args);
if (s.length() > 0) {
s.append(" ");
}
s.append(CSVFormat.EG_FORMAT.format(line.getProbability(), Encog.DEFAULT_PRECISION));
}
} while (BIFUtil.rollArgs(event, args));
return s.toString();
}
