diff --git a/pdb-plotting/src/main/java/org/lucares/recommind/logs/GnuplotFileGenerator.java b/pdb-plotting/src/main/java/org/lucares/recommind/logs/GnuplotFileGenerator.java
index 0de09c2..8b1f507 100644
--- a/pdb-plotting/src/main/java/org/lucares/recommind/logs/GnuplotFileGenerator.java
+++ b/pdb-plotting/src/main/java/org/lucares/recommind/logs/GnuplotFileGenerator.java
@@ -35,17 +35,31 @@ public class GnuplotFileGenerator {
 		appendfln(result, "set xlabel \"%s\"", settings.getXlabel());
 		appendfln(result, "set xtics rotate by %d", settings.getRotateXAxisLabel());
 		appendfln(result, "set xrange [\"%s\":\"%s\"]", settings.getDateFrom(), settings.getDateTo());
-		appendfln(result, "set yrange [\"1\":]");
+		
+		final long graphOffset = settings.getYAxisScale() == AxisScale.LINEAR ? 0 : 1;
+		appendfln(result, "set yrange [\""+graphOffset+"\":]");
 		
 		appendfln(result, "set ylabel \"%s\"", settings.getYlabel());
-		if (settings.getYAxisScale() == AxisScale.LOG10) {
+		switch (settings.getYAxisScale()) {
+		case LINEAR:
+			break;
+		case LOG10:
 			appendfln(result, "set logscale y");
-		} else if (settings.getYAxisScale() == AxisScale.LOG2) {
+			break;
+		case LOG2:
 			appendfln(result, "set logscale y 2");
+			break;
 		}
 
 		appendfln(result, "set grid");
 		appendfln(result, "set output \"%s\"", settings.getOutput().toAbsolutePath().toString().replace("\\", "/"));
+		
+		// marker lines that show which area will be zoomed
+		final long minDate = Long.parseLong(settings.getDateFrom());
+		final long maxDate = Long.parseLong(settings.getDateTo());
+		appendfln(result, "set arrow from "+(minDate + (maxDate-minDate)*0.25)+","+graphOffset+" rto graph 0,1 lt 3 lc rgb \"#EEEEEE\" nohead");
+		appendfln(result, "set arrow from "+(minDate + (maxDate-minDate)*0.75)+","+graphOffset+" rto graph 0,1 lc rgb \"#EEEEEE\" nohead");
+		
 		appendf(result, "plot ");
 		
 		count = 1;