range definitions for the y-axis

Sometimes it is useful to specify the certain y-axis range. For example
when you are only interested in the values that take longer than a
threshold. Or when you want to exclude some outliers. When you want to
compare plots in a gallery, it is very handy when all plots have the
same data-area.

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

@@ -28,8 +28,14 @@ public class GnuplotFileGenerator {
 		appendfln(result, "set xlabel \"%s\"", xAxis.getXlabel());
 		appendfln(result, "set xrange [\"%s\":\"%s\"]", xAxis.getFrom(), xAxis.getTo());
 
-		final long graphOffset = settings.getYAxisScale() == AxisScale.LINEAR ? 0 : 1;
-		appendfln(result, "set yrange [\"" + graphOffset + "\":]");
+		final int graphOffset = settings.getYAxisScale() == AxisScale.LINEAR ? 0 : 1;
+		if (settings.hasYRange()) {
+			final int min = Math.max(settings.getYRangeMin(), graphOffset);
+			final int max = settings.getYRangeMax();
+			appendfln(result, String.format("set yrange [\"%d\":\"%d\"]", min, max));
+		} else {
+			appendfln(result, "set yrange [\"" + graphOffset + "\":]");
+		}
 
 		appendfln(result, "set ylabel \"%s\"", settings.getYlabel());
 		switch (settings.getYAxisScale()) {

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

@@ -26,6 +26,8 @@ public class GnuplotSettings {
 
 	private XAxisSettings xAxisSettings = new XAxisSettings();
 	private boolean renderLabels = true;
+	private int yRangeMin = -1;
+	private int yRangeMax = -1;
 
 	public GnuplotSettings(final Path output) {
 		this.output = output;
@@ -123,6 +125,23 @@ public class GnuplotSettings {
 		return renderLabels;
 	}
 
+	public boolean hasYRange() {
+		return yRangeMin >= 0 && yRangeMax >= 0 && yRangeMin < yRangeMax;
+	}
+
+	public void setYRange(final int yRangeMin, final int yRangeMax) {
+		this.yRangeMin = yRangeMin;
+		this.yRangeMax = yRangeMax;
+	}
+
+	public int getYRangeMin() {
+		return yRangeMin;
+	}
+
+	public int getYRangeMax() {
+		return yRangeMax;
+	}
+
 	// plot 'sample.txt' using 1:2 title 'Bytes' with linespoints 2
 
 }

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

@@ -30,6 +30,7 @@ import org.lucares.pdb.api.Tags;
 import org.lucares.pdb.plot.api.CustomAggregator;
 import org.lucares.pdb.plot.api.Limit;
 import org.lucares.pdb.plot.api.PlotSettings;
+import org.lucares.pdb.plot.api.TimeRangeUnitInternal;
 import org.lucares.performance.db.PerformanceDb;
 import org.lucares.utils.file.FileUtils;
 import org.slf4j.Logger;
@@ -120,6 +121,8 @@ public class ScatterPlot {
 
 				gnuplotSettings.setYAxisScale(plotSettings.getYAxisScale());
 				gnuplotSettings.setAggregate(plotSettings.getAggregate());
+				defineYRange(gnuplotSettings, plotSettings.getYRangeMin(), plotSettings.getYRangeMax(),
+						plotSettings.getYRangeUnit());
 				gnuplotSettings.setKeyOutside(plotSettings.isKeyOutside());
 				gnuplot.plot(gnuplotSettings, dataSeries);
 			}
@@ -135,6 +138,8 @@ public class ScatterPlot {
 
 				gnuplotSettings.setYAxisScale(plotSettings.getYAxisScale());
 				gnuplotSettings.setAggregate(plotSettings.getAggregate());
+				defineYRange(gnuplotSettings, plotSettings.getYRangeMin(), plotSettings.getYRangeMax(),
+						plotSettings.getYRangeUnit());
 				gnuplotSettings.setKeyOutside(false);
 				gnuplotSettings.renderLabels(false);
 				gnuplot.plot(gnuplotSettings, dataSeries);
@@ -154,6 +159,16 @@ public class ScatterPlot {
 		}
 	}
 
+	private void defineYRange(final GnuplotSettings gnuplotSettings, final int yRangeMin, final int yRangeMax,
+			final TimeRangeUnitInternal yRangeUnit) {
+
+		if (yRangeUnit != TimeRangeUnitInternal.AUTOMATIC) {
+			final int min = yRangeUnit.toMilliSeconds(yRangeMin);
+			final int max = yRangeUnit.toMilliSeconds(yRangeMax);
+			gnuplotSettings.setYRange(min, max);
+		}
+	}
+
 	private void defineXAxis(final GnuplotSettings gnuplotSettings, final OffsetDateTime minDate,
 			final OffsetDateTime maxDate) {