package com.rapidminer.operator.RatingPrediction;
import java.util.LinkedList;
import java.util.List;
import com.rapidminer.operator.Annotations;
import com.rapidminer.operator.IOObject;
import com.rapidminer.operator.Operator;
import com.rapidminer.operator.ports.OutputPort;
import com.rapidminer.operator.ports.ProcessingStep;
import com.rapidminer.tools.LogService;
import com.rapidminer.tools.LoggingHandler;
/**
*Created by Matej Mihelcic (Ru�er Bo�kovi� Institute) 25.08.2011
*
*Random rating predictor, use for comparison
*/
public class Random extends RatingPredictor {
static final long serialVersionUID=1942342347;
public boolean use_normal=false;
public double stdev=0.1;
public double mean=0;
public void Train(){
}
public double Predict(int user_id, int item_id){
java.util.Random pred1=new java.util.Random();
com.rapidminer.utils.Random pred=new com.rapidminer.utils.Random();
if(use_normal==false)
return pred1.nextDouble()*max_rating;
else{
double temp=Math.abs(pred.NextNormal(mean,stdev))*max_rating;
while(temp>max_rating)
temp/=10;
return temp;
}
}
public void LoadModel(String filename){
}
public void SaveModel(String filename){
}
///
public String ToString()
{
return "";
}
private String source = null;
/** The current working operator. */
private transient LoggingHandler loggingHandler;
private transient LinkedList<ProcessingStep> processingHistory = new LinkedList<ProcessingStep>();
/** Sets the source of this IOObject. */
public void setSource(String sourceName) {
this.source = sourceName;
}
/** Returns the source of this IOObject (might return null if the source is unknown). */
public String getSource() {
return source;
}
@Override
public void appendOperatorToHistory(Operator operator, OutputPort port) {
if (processingHistory == null) {
processingHistory = new LinkedList<ProcessingStep>();
if (operator.getProcess() != null)
processingHistory.add(new ProcessingStep(operator, port));
}
ProcessingStep newStep = new ProcessingStep(operator, port);
if (operator.getProcess() != null && (processingHistory.isEmpty() || !processingHistory.getLast().equals(newStep))) {
processingHistory.add(newStep);
}
}
@Override
public List<ProcessingStep> getProcessingHistory() {
if (processingHistory == null)
processingHistory = new LinkedList<ProcessingStep>();
return processingHistory;
}
/** Gets the logging associated with the operator currently working on this
* IOObject or the global log service if no operator was set. */
public LoggingHandler getLog() {
if (this.loggingHandler != null) {
return this.loggingHandler;
} else {
return LogService.getGlobal();
}
}
/** Sets the current working operator, i.e. the operator which is currently
* working on this IOObject. This might be used for example for logging. */
public void setLoggingHandler(LoggingHandler loggingHandler) {
this.loggingHandler = loggingHandler;
}
/**
* Returns not a copy but the very same object. This is ok for IOObjects
* which cannot be altered after creation. However, IOObjects which might be
* changed (e.g. {@link com.rapidminer.example.ExampleSet}s) should
* overwrite this method and return a proper copy.
*/
public IOObject copy() {
return this;
}
protected void initWriting() {}
public Annotations getAnnotations(){
Annotations temp=new Annotations();
return temp;
}
}