Remove some currently unused methods (mean, variance, etc.) from Distribution.

Currently these do not actually make much sense anyway since the class is primarily
intended to store distributions over indices into some other list (e.g., states).

prism/src/explicit/Distribution.java

@@ -29,7 +29,6 @@ package explicit;
 import java.util.BitSet;
 import java.util.HashMap;
 import java.util.Iterator;
-import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Set;
@@ -205,7 +204,7 @@ public class Distribution implements Iterable<Entry<Integer, Double>>
 	/**
 	 * Get the mean of the distribution.
 	 */
-	public double mean()
+	/*public double mean()
 	{
 		double d = 0.0;
 		Iterator<Entry<Integer, Double>> i = iterator();
@@ -214,12 +213,12 @@ public class Distribution implements Iterable<Entry<Integer, Double>>
 			d += e.getValue() * e.getKey();
 		}
 		return d;
-	}
+	}*/
 	
 	/**
 	 * Get the variance of the distribution.
 	 */
-	public double variance()
+	/*public double variance()
 	{
 		double mean = mean();
 		double meanSq = 0.0;
@@ -229,24 +228,24 @@ public class Distribution implements Iterable<Entry<Integer, Double>>
 			meanSq += e.getValue() * e.getKey() * e.getKey();
 		}
 		return Math.abs(meanSq - mean * mean);
-	}
+	}*/
 	
 	/**
 	 * Get the standard deviation of the distribution.
 	 */
-	public double standardDeviation()
+	/*public double standardDeviation()
 	{
 		return Math.sqrt(variance());
-	}
+	}*/
 	
 	/**
 	 * Get the relative standard deviation of the distribution,
 	 * i.e., as a percentage of the mean.
 	 */
-	public double standardDeviationRelative()
+	/*public double standardDeviationRelative()
 	{
 		return 100.0 * standardDeviation() / mean();
-	}
+	}*/
 	
 	/**
 	 * Get the sum of the probabilities in the distribution.