--- a/pce.c	Wed Dec 21 22:26:20 2011 +0100
+++ b/pce.c	Wed Dec 21 23:02:04 2011 +0100
@@ -198,6 +198,10 @@
 
     fprintf(outfile, "# Time between samples: %i s\n",
             time_per_sample);
+
+    fprintf(outfile, "set xdata time; set timefmt \"%%s\"; plot \"-\" using 2:3 "
+            "with lines title \"temp\", \"\" using 2:4 with lines title \"hum\"; pause -1\n");
+
 }
 
 int