[Jrobin-commits] src/org/jrobin/data DataProcessor.java,1.3,1.4 Source.java,1.1,1.2

[Sasa M. <sa...@us...>]

Update of /cvsroot/jrobin/src/org/jrobin/data
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv23351/org/jrobin/data

Modified Files:
	DataProcessor.java Source.java 
Log Message:
Implemented 95th percentile for datasource values (see get95Percentile method in the DataAnalyzer class). Minor changes in the core package.

Index: Source.java
===================================================================
RCS file: /cvsroot/jrobin/src/org/jrobin/data/Source.java,v
retrieving revision 1.1
retrieving revision 1.2
diff -C2 -d -r1.1 -r1.2
*** Source.java	25 Nov 2004 12:14:54 -0000	1.1
--- Source.java	8 Dec 2004 14:02:37 -0000	1.2
***************
*** 30,33 ****
--- 30,35 ----
  import org.jrobin.core.Util;
  
+ import java.util.Arrays;
+ 
  abstract class Source implements ConsolFuns {
  	final private String name;
***************
*** 78,81 ****
--- 80,118 ----
  	}
  
+ 	final double getPercentile(int percentile) throws RrdException {
+ 		if(values == null) {
+ 			throw new RrdException("Could not calculate 95th percentile for datasource [" +
+ 					name + "], datasource values are still not available");
+ 		}
+ 		if(percentile > 100 || percentile <= 0) {
+ 			throw new RrdException("Invalid percentile specified: " + percentile);
+ 		}
+ 		return getPercentile(values, percentile);
+ 	}
+ 
+ 	private static double getPercentile(double[] values, int percentile) {
+ 		int count = values.length;
+ 		double[] valuesCopy = new double[count];
+ 		for(int i = 0; i < count; i++) {
+ 			valuesCopy[i] = values[i];
+ 		}
+ 		Arrays.sort(valuesCopy);
+ 		// NaN values are at the end, eliminate them from consideration
+ 		while(count > 0 && Double.isNaN(valuesCopy[count - 1])) {
+ 			count--;
+ 		}
+ 		// skip top [percentile]% values
+ 		int skipCount = (int) Math.ceil(((100 - percentile) * count) / 100.0);
+ 		count -= skipCount;
+ 		// if we have anything left...
+ 		if(count > 0) {
+ 			return valuesCopy[count - 1];
+ 		}
+ 		else {
+ 			// not enough data available
+ 			return Double.NaN;
+ 		}
+ 	}
+ 
  	private double getTotal(double secondsPerPixel) {
  		double sum = 0;
***************
*** 115,118 ****
  		return min;
  	}
- 
  }
--- 152,154 ----

Index: DataProcessor.java
===================================================================
RCS file: /cvsroot/jrobin/src/org/jrobin/data/DataProcessor.java,v
retrieving revision 1.3
retrieving revision 1.4
diff -C2 -d -r1.3 -r1.4
*** DataProcessor.java	26 Nov 2004 13:47:51 -0000	1.3
--- DataProcessor.java	8 Dec 2004 14:02:37 -0000	1.4
***************
*** 240,243 ****
--- 240,263 ----
  
  	/**
+ 	 * Used by ISPs which charge for bandwidth utilization on a "95th percentile" basis.<p>
+ 	 *
+ 	 * The 95th percentile is the highest source value left when the top 5% of a numerically sorted set
+ 	 * of source data is discarded. It is used as a measure of the peak value used when one discounts
+ 	 * a fair amount for transitory spikes. This makes it markedly different from the average.<p>
+ 	 *
+ 	 * Read more about this topic at
+ 	 * <a href="http://www.red.net/support/resourcecentre/leasedline/percentile.php">Rednet</a> or
+ 	 * <a href="http://www.bytemark.co.uk/support/tech/95thpercentile.html">Bytemark</a>.
+ 	 *
+ 	 * @param sourceName Datasource name
+ 	 * @return 95th percentile of fetched source values
+ 	 * @throws RrdException Thrown if invalid source name is supplied
+ 	 */
+ 	public double get95Percentile(String sourceName) throws RrdException {
+ 		Source source = getSource(sourceName);
+ 		return source.getPercentile(95);
+ 	}
+ 
+ 	/**
  	 * Returns array of datasource names defined in this DataProcessor.
  	 * @return array of datasource names