diff --git a/src/main/java/org/gcube/dataanalysis/geo/algorithms/MapsComparator.java b/src/main/java/org/gcube/dataanalysis/geo/algorithms/MapsComparator.java
index 3a258e4..82b2f5c 100644
--- a/src/main/java/org/gcube/dataanalysis/geo/algorithms/MapsComparator.java
+++ b/src/main/java/org/gcube/dataanalysis/geo/algorithms/MapsComparator.java
@@ -329,7 +329,9 @@ public class MapsComparator extends DataAnalysis {
 		double mean = 0;
 		try{mean = Double.parseDouble(outputParameters.get("MEAN"));}catch(Exception e){}
 		double variance = 0;
-		try{variance = Double.parseDouble(outputParameters.get("VARIANCE"));}catch(Exception e){}
+		try{variance = Double.parseDouble(outputParameters.get("VARIANCE"));
+		variance = Math.sqrt(variance);//use std deviation
+		}catch(Exception e){}
 		producedImages.put("Error Distribution", generateGaussian(mean, variance));
 		PrimitiveType images = new PrimitiveType("Images", producedImages, PrimitiveTypes.IMAGES, "Distribution of the Error", "The distribution of the error along with variance");