add logarithmic scaling for the y-axis

Often we have a few very high values and a lot
low values. With a linearly scaled y-axis the
plot is mostly useless.

pdb-plotting/src/main/java/org/lucares/pdb/plot/api/AxisScale.java

@@ -0,0 +1,5 @@
+package org.lucares.pdb.plot.api;
+
+public enum AxisScale {
+	LINEAR, LOG10, LOG2
+}

pdb-plotting/src/main/java/org/lucares/pdb/plot/api/PlotSettings.java

@@ -30,6 +30,8 @@ public class PlotSettings {
 
 	private String dateRange;
 
+	private AxisScale yAxisScale;
+
 	public String getQuery() {
 		return query;
 	}
@@ -142,11 +144,18 @@ public class PlotSettings {
 		}
 	}
 
+	public void setYAxisScale(final AxisScale axisScale) {
+		this.yAxisScale = axisScale;
+	}
+
+	public AxisScale getYAxisScale() {
+		return yAxisScale;
+	}
+
 	@Override
 	public String toString() {
 		return "PlotSettings [query=" + query + ", height=" + height + ", width=" + width + ", groupBy=" + groupBy
 				+ ", limitBy=" + limitBy + ", limit=" + limit + ", dateFrom=" + dateFrom + ", dateRange=" + dateRange
-				+ "]";
+				+ ", axisScale=" + yAxisScale + "]";
 	}
-
 }

pdb-plotting/src/main/java/org/lucares/recommind/logs/GnuplotFileGenerator.java

@@ -2,6 +2,8 @@ package org.lucares.recommind.logs;
 
 import java.util.Collection;
 
+import org.lucares.pdb.plot.api.AxisScale;
+
 public class GnuplotFileGenerator {
 
 	public String generate(final GnuplotSettings settings, final Collection<DataSeries> dataSeries) {
@@ -20,6 +22,11 @@ public class GnuplotFileGenerator {
 		appendfln(result, "set xtics rotate by %d", settings.getRotateXAxisLabel());
 
 		appendfln(result, "set ylabel \"%s\"", settings.getYlabel());
+		if (settings.getYAxisScale() == AxisScale.LOG10) {
+			appendfln(result, "set logscale y");
+		} else if (settings.getYAxisScale() == AxisScale.LOG2) {
+			appendfln(result, "set logscale y 2");
+		}
 
 		appendfln(result, "set output \"%s\"", settings.getOutput().toAbsolutePath().toString().replace("\\", "/"));
 		appendf(result, "plot ");

pdb-plotting/src/main/java/org/lucares/recommind/logs/GnuplotSettings.java

@@ -2,6 +2,8 @@ package org.lucares.recommind.logs;
 
 import java.nio.file.Path;
 
+import org.lucares.pdb.plot.api.AxisScale;
+
 public class GnuplotSettings {
 	private String terminal = "png";
 	private int height = 1200;
@@ -25,6 +27,7 @@ public class GnuplotSettings {
 
 	// set xtics rotate by 80
 	private int rotateXAxisLabel = -80;
+	private AxisScale yAxisScale;
 
 	public GnuplotSettings(final Path output) {
 		this.output = output;
@@ -106,6 +109,14 @@ public class GnuplotSettings {
 		return output;
 	}
 
+	public void setYAxisScale(final AxisScale yAxisScale) {
+		this.yAxisScale = yAxisScale;
+	}
+
+	public AxisScale getYAxisScale() {
+		return yAxisScale;
+	}
+
 	// plot 'sample.txt' using 1:2 title 'Bytes' with linespoints 2
 
 }

pdb-plotting/src/main/java/org/lucares/recommind/logs/Plotter.java

@@ -110,6 +110,7 @@ public class Plotter {
 			gnuplotSettings.setHeight(height);
 			gnuplotSettings.setWidth(width);
 			gnuplotSettings.setFormatX(getFormatX(minDate, maxDate));
+			gnuplotSettings.setYAxisScale(plotSettings.getYAxisScale());
 			gnuplot.plot(gnuplotSettings, dataSeries);
 
 			return new PlotResult(outputFile.getFileName(), dataSeries);

pdb-ui/src/main/java/org/lucares/pdbui/PlotSettingsTransformer.java

@@ -1,9 +1,11 @@
 package org.lucares.pdbui;
 
+import org.lucares.pdb.plot.api.AxisScale;
 import org.lucares.pdb.plot.api.Limit;
 import org.lucares.pdb.plot.api.PlotSettings;
 import org.lucares.pdbui.domain.LimitBy;
 import org.lucares.pdbui.domain.PlotRequest;
+import org.lucares.pdbui.domain.YAxis;
 
 class PlotSettingsTransformer {
 	static PlotSettings toSettings(final PlotRequest request) {
@@ -18,10 +20,24 @@ class PlotSettingsTransformer {
 		result.setLimitBy(toLimit(request.getLimitBy()));
 		result.setDateFrom(request.getDateFrom());
 		result.setDateRange(request.getDateRange());
+		result.setYAxisScale(toAxisScale(request.getAxisScale()));
 
 		return result;
 	}
 
+	private static AxisScale toAxisScale(final YAxis yAxis) {
+		switch (yAxis) {
+		case LINEAR:
+			return AxisScale.LINEAR;
+		case LOG10:
+			return AxisScale.LOG10;
+		case LOG2:
+			return AxisScale.LOG2;
+		default:
+			throw new IllegalStateException("unhandled enum: " + yAxis);
+		}
+	}
+
 	private static Limit toLimit(final LimitBy limitBy) {
 		switch (limitBy) {
 		case NO_LIMIT:

pdb-ui/src/main/java/org/lucares/pdbui/domain/PlotRequest.java

@@ -13,6 +13,8 @@ public class PlotRequest {
 
 	private LimitBy limitBy = LimitBy.NO_LIMIT;
 
+	private YAxis yAxis = YAxis.LINEAR;
+
 	private int limit = Integer.MAX_VALUE;
 
 	private String dateFrom;
@@ -91,4 +93,11 @@ public class PlotRequest {
 		this.dateRange = dateRange;
 	}
 
+	public YAxis getAxisScale() {
+		return yAxis;
+	}
+
+	public void setAxisScale(final YAxis yAxis) {
+		this.yAxis = yAxis;
+	}
 }

pdb-ui/src/main/java/org/lucares/pdbui/domain/YAxis.java

@@ -0,0 +1,5 @@
+package org.lucares.pdbui.domain;
+
+public enum YAxis {
+	LINEAR, LOG10, LOG2
+}

pdb-ui/src/main/resources/resources/js/search.js

@@ -96,6 +96,7 @@ function plot(event){
 	request['limit'] = parseInt($('#search-limit-value').val());
 	request['dateFrom'] = $('#search-date-from').val();
 	request['dateRange'] = $('#search-date-range').val();
+	request['axisScale'] = $('#search-y-axis-scale').val();
 	
 	
 	var success = function(response){

pdb-ui/src/main/resources/templates/main.html

@@ -46,6 +46,13 @@
 			<option value="1 month">
 		</datalist>
 		
+		<label for="search-y-axis-scale">y-axis:</label>
+		<select id="search-y-axis-scale">
+			<option value="LINEAR" selected="selected">linear</option>
+			<option value="LOG10">log 10</option>
+			<option value="LOG2">log 2</option>
+		</select>
+		
 		<button id="search-submit"><i class="fa fa-area-chart"> Plot</i></button>
 	</div>
 	<div id="result-view">