/** Registers variables in the filter */
public void register(DataFilter filter) {
if (varName != null) {
filter.addData(DataCollectorDescription.VARIABLE, varName);
} else if (function != null) {
function.register(filter);
}
}
/** Reads a value from the data */
public Double getValue(DataRow data) throws Exception {
Double value;
if (varName != null) {
value = data.getVarDoubleValue(varName);
} else if (function != null) {
value = function.evaluate(data);
} else {
return null;
}
return value;
}