diff --git a/example/COLVAR+0.0 b/example/COLVAR+0.0.xvg
similarity index 100%
rename from example/COLVAR+0.0
rename to example/COLVAR+0.0.xvg
diff --git a/example/COLVAR+0.25 b/example/COLVAR+0.25.xvg
similarity index 100%
rename from example/COLVAR+0.25
rename to example/COLVAR+0.25.xvg
diff --git a/example/COLVAR+0.5 b/example/COLVAR+0.5.xvg
similarity index 100%
rename from example/COLVAR+0.5
rename to example/COLVAR+0.5.xvg
diff --git a/example/COLVAR+0.75 b/example/COLVAR+0.75.xvg
similarity index 100%
rename from example/COLVAR+0.75
rename to example/COLVAR+0.75.xvg
diff --git a/example/COLVAR+1.0 b/example/COLVAR+1.0.xvg
similarity index 100%
rename from example/COLVAR+1.0
rename to example/COLVAR+1.0.xvg
diff --git a/example/COLVAR+1.25 b/example/COLVAR+1.25.xvg
similarity index 100%
rename from example/COLVAR+1.25
rename to example/COLVAR+1.25.xvg
diff --git a/example/COLVAR+1.5 b/example/COLVAR+1.5.xvg
similarity index 100%
rename from example/COLVAR+1.5
rename to example/COLVAR+1.5.xvg
diff --git a/example/COLVAR+1.75 b/example/COLVAR+1.75.xvg
similarity index 100%
rename from example/COLVAR+1.75
rename to example/COLVAR+1.75.xvg
diff --git a/example/COLVAR+2.0 b/example/COLVAR+2.0.xvg
similarity index 100%
rename from example/COLVAR+2.0
rename to example/COLVAR+2.0.xvg
diff --git a/example/COLVAR+2.25 b/example/COLVAR+2.25.xvg
similarity index 100%
rename from example/COLVAR+2.25
rename to example/COLVAR+2.25.xvg
diff --git a/example/COLVAR+2.5 b/example/COLVAR+2.5.xvg
similarity index 100%
rename from example/COLVAR+2.5
rename to example/COLVAR+2.5.xvg
diff --git a/example/COLVAR+2.75 b/example/COLVAR+2.75.xvg
similarity index 100%
rename from example/COLVAR+2.75
rename to example/COLVAR+2.75.xvg
diff --git a/example/COLVAR+3.0 b/example/COLVAR+3.0.xvg
similarity index 100%
rename from example/COLVAR+3.0
rename to example/COLVAR+3.0.xvg
diff --git a/example/COLVAR-0.25 b/example/COLVAR-0.25.xvg
similarity index 100%
rename from example/COLVAR-0.25
rename to example/COLVAR-0.25.xvg
diff --git a/example/COLVAR-0.5 b/example/COLVAR-0.5.xvg
similarity index 100%
rename from example/COLVAR-0.5
rename to example/COLVAR-0.5.xvg
diff --git a/example/COLVAR-0.75 b/example/COLVAR-0.75.xvg
similarity index 100%
rename from example/COLVAR-0.75
rename to example/COLVAR-0.75.xvg
diff --git a/example/COLVAR-1.0 b/example/COLVAR-1.0.xvg
similarity index 100%
rename from example/COLVAR-1.0
rename to example/COLVAR-1.0.xvg
diff --git a/example/COLVAR-1.25 b/example/COLVAR-1.25.xvg
similarity index 100%
rename from example/COLVAR-1.25
rename to example/COLVAR-1.25.xvg
diff --git a/example/COLVAR-1.5 b/example/COLVAR-1.5.xvg
similarity index 100%
rename from example/COLVAR-1.5
rename to example/COLVAR-1.5.xvg
diff --git a/example/COLVAR-1.75 b/example/COLVAR-1.75.xvg
similarity index 100%
rename from example/COLVAR-1.75
rename to example/COLVAR-1.75.xvg
diff --git a/example/COLVAR-2.0 b/example/COLVAR-2.0.xvg
similarity index 100%
rename from example/COLVAR-2.0
rename to example/COLVAR-2.0.xvg
diff --git a/example/COLVAR-2.25 b/example/COLVAR-2.25.xvg
similarity index 100%
rename from example/COLVAR-2.25
rename to example/COLVAR-2.25.xvg
diff --git a/example/COLVAR-2.5 b/example/COLVAR-2.5.xvg
similarity index 100%
rename from example/COLVAR-2.5
rename to example/COLVAR-2.5.xvg
diff --git a/example/COLVAR-2.75 b/example/COLVAR-2.75.xvg
similarity index 100%
rename from example/COLVAR-2.75
rename to example/COLVAR-2.75.xvg
diff --git a/example/COLVAR-3.0 b/example/COLVAR-3.0.xvg
similarity index 100%
rename from example/COLVAR-3.0
rename to example/COLVAR-3.0.xvg
diff --git a/example/COLVAR0.75 b/example/COLVAR0.75.xvg
similarity index 100%
rename from example/COLVAR0.75
rename to example/COLVAR0.75.xvg
diff --git a/example/metadata.dat b/example/metadata.dat
index 3bea270..26c435f 100644
--- a/example/metadata.dat
+++ b/example/metadata.dat
@@ -1,25 +1,25 @@
-COLVAR+0.0	 0.0	    100
-COLVAR+0.25	 0.25	    100
-COLVAR+0.5	 0.5	    100
-COLVAR+0.75	 0.75	    100
-COLVAR+1.0	 1.0	    100
-COLVAR+1.25	 1.25	    100
-COLVAR+1.5	 1.5	    100
-COLVAR+1.75	 1.75	    100
-COLVAR+2.0	 2.0	    100
-COLVAR+2.25	 2.25	    100
-COLVAR+2.5	 2.5	    100
-COLVAR+2.75	 2.75	    100
-COLVAR+3.0	 3.0	    100
-COLVAR-0.25	 -0.25	    100
-COLVAR-0.5	 -0.5	    100
-COLVAR-0.75	 -0.75	    100
-COLVAR-1.0	 -1.0	    100
-COLVAR-1.25	 -1.25	    100
-COLVAR-1.5	 -1.5	    100
-COLVAR-1.75	 -1.75	    100
-COLVAR-2.0	 -2.0	    100
-COLVAR-2.25	 -2.25	    100
-COLVAR-2.5	 -2.5	    100
-COLVAR-2.75	 -2.75	    100
-COLVAR-3.0	 -3.0	    100
+COLVAR+0.0.xvg	 0.0	    100
+COLVAR+0.25.xvg	 0.25	    100
+COLVAR+0.5.xvg	 0.5	    100
+COLVAR+0.75.xvg	 0.75	    100
+COLVAR+1.0.xvg	 1.0	    100
+COLVAR+1.25.xvg	 1.25	    100
+COLVAR+1.5.xvg	 1.5	    100
+COLVAR+1.75.xvg	 1.75	    100
+COLVAR+2.0.xvg	 2.0	    100
+COLVAR+2.25.xvg	 2.25	    100
+COLVAR+2.5.xvg	 2.5	    100
+COLVAR+2.75.xvg	 2.75	    100
+COLVAR+3.0.xvg	 3.0	    100
+COLVAR-0.25.xvg	 -0.25	    100
+COLVAR-0.5.xvg	 -0.5	    100
+COLVAR-0.75.xvg	 -0.75	    100
+COLVAR-1.0.xvg	 -1.0	    100
+COLVAR-1.25.xvg	 -1.25	    100
+COLVAR-1.5.xvg	 -1.5	    100
+COLVAR-1.75.xvg	 -1.75	    100
+COLVAR-2.0.xvg	 -2.0	    100
+COLVAR-2.25.xvg	 -2.25	    100
+COLVAR-2.5.xvg	 -2.5	    100
+COLVAR-2.75.xvg	 -2.75	    100
+COLVAR-3.0.xvg	 -3.0	    100