@Override
public void perform() throws TaskException {
try {
Instances[] data = this.readAndCheckData();
for (int i = 0; i < data.length; ++i) {
String oldName = data[i].relationName();
Filter filter = this.initFilter(data[i]);
data[i] = Filter.useFilter(data[i], filter);
data[i].setRelationName(oldName); // keep the old relation name
FileUtils.writeArff(this.output.get(i), data[i]);
}
} catch (TaskException e) {
throw e;
} catch (Exception e) {
Logger.getInstance().logStackTrace(e, Logger.V_DEBUG);
throw new TaskException(TaskException.ERR_IO_ERROR, this.id, e.getMessage());
}
}
/**
* This reads all the input data and checks their headers if they're identical and sets the class
* attribute if provided in the input parameters.
*
* @return all the data read from the individual files
*/
private Instances[] readAndCheckData() throws Exception {
Instances[] data = new Instances[this.input.size()];
for (int i = 0; i < this.input.size(); ++i) {
data[i] = FileUtils.readArff(this.input.get(i));
}
for (int i = 1; i < this.input.size(); ++i) {
if (!data[i].equalHeaders(data[0])) {
throw new TaskException(
TaskException.ERR_INVALID_DATA,
this.id,
"Files "
+ this.input.get(i)
+ " and "
+ this.input.get(0)
+ " don't have equal headers.");
}
}
// set class attribute if set in the data
if (this.hasParameter(GeneralClassifier.CLASS_ARG)) {
String className = this.parameters.remove(GeneralClassifier.CLASS_ARG);
for (int i = 0; i < data.length; ++i) {
Attribute classAttr = data[i].attribute(className);
if (classAttr == null) {
throw new TaskException(
TaskException.ERR_INVALID_DATA,
this.id,
"Class attribute " + className + " not found in the input data.");
}
data[i].setClass(classAttr);
}
}
return data;
}