diff --git a/pdb-plotting/src/main/java/org/lucares/recommind/logs/FileBackedDataSeries.java b/pdb-plotting/src/main/java/org/lucares/recommind/logs/FileBackedDataSeries.java
index c0817e6..ad12ed2 100644
--- a/pdb-plotting/src/main/java/org/lucares/recommind/logs/FileBackedDataSeries.java
+++ b/pdb-plotting/src/main/java/org/lucares/recommind/logs/FileBackedDataSeries.java
@@ -12,10 +12,10 @@ public class FileBackedDataSeries implements DataSeries {
 
 	private String id;
 
-	private String linetype;
+	private GnuplotLineType linetype;
 	
 
-	public FileBackedDataSeries(String id, String title, CsvSummary csvSummary, String linetype) {
+	public FileBackedDataSeries(String id, String title, CsvSummary csvSummary, GnuplotLineType linetype) {
 		this.id = id;
 		this.title = title;
 		this.csvSummary = csvSummary;
diff --git a/pdb-plotting/src/main/java/org/lucares/recommind/logs/GnuplotLineType.java b/pdb-plotting/src/main/java/org/lucares/recommind/logs/GnuplotLineType.java
new file mode 100644
index 0000000..427f86d
--- /dev/null
+++ b/pdb-plotting/src/main/java/org/lucares/recommind/logs/GnuplotLineType.java
@@ -0,0 +1,20 @@
+package org.lucares.recommind.logs;
+
+public enum GnuplotLineType {
+	LINE("line"),
+	
+	Points("points");
+	
+	private String gnuplotLineType;
+
+	GnuplotLineType(String gnuplotLineType) {
+		this.gnuplotLineType = gnuplotLineType;
+	}
+
+	@Override
+	public String toString() {
+		return gnuplotLineType;
+	}
+	
+}
+
diff --git a/pdb-plotting/src/main/java/org/lucares/recommind/logs/PercentilePlot.java b/pdb-plotting/src/main/java/org/lucares/recommind/logs/PercentilePlot.java
index 19660f6..d78ee3b 100644
--- a/pdb-plotting/src/main/java/org/lucares/recommind/logs/PercentilePlot.java
+++ b/pdb-plotting/src/main/java/org/lucares/recommind/logs/PercentilePlot.java
@@ -193,7 +193,7 @@ public class PercentilePlot implements ConcretePlotter {
 				values.size());
 
 		CsvSummary csvSummary = new CsvSummary(dataFile, values.size(), maxValue, null);
-		return new FileBackedDataSeries(id, title,  csvSummary, "line");
+		return new FileBackedDataSeries(id, title,  csvSummary, GnuplotLineType.LINE);
 	}
 
 	private void defineXAxis(GnuplotSettings gnuplotSettings) {
diff --git a/pdb-plotting/src/main/java/org/lucares/recommind/logs/ScatterPlot.java b/pdb-plotting/src/main/java/org/lucares/recommind/logs/ScatterPlot.java
index c947da4..e799ab1 100644
--- a/pdb-plotting/src/main/java/org/lucares/recommind/logs/ScatterPlot.java
+++ b/pdb-plotting/src/main/java/org/lucares/recommind/logs/ScatterPlot.java
@@ -88,7 +88,7 @@ public class ScatterPlot implements ConcretePlotter {
 	
 					final int id = idCounter.getAndIncrement();
 					final String title = ConcretePlotter.title(groupResult.getGroupedBy(), csvSummary.getValues());
-					final DataSeries dataSerie = new FileBackedDataSeries("id"+id, title, csvSummary, "points");
+					final DataSeries dataSerie = new FileBackedDataSeries("id"+id, title, csvSummary, GnuplotLineType.Points);
 					if (dataSerie.getValues() > 0) {
 						dataSeries.add(dataSerie);
 					}