Index: /trunk/PS-IPP-Config/lib/PS/IPP/Metadata/Stats.pm
===================================================================
--- /trunk/PS-IPP-Config/lib/PS/IPP/Metadata/Stats.pm	(revision 17601)
+++ /trunk/PS-IPP-Config/lib/PS/IPP/Metadata/Stats.pm	(revision 17602)
@@ -1,5 +1,5 @@
 # Copyright (c) 2006  Paul Price, Joshua Hoblitt
 #
-# $Id: Stats.pm,v 1.27 2008-04-11 07:37:14 eugene Exp $
+# $Id: Stats.pm,v 1.28 2008-05-09 21:02:21 eugene Exp $
 
 package PS::IPP::Metadata::Stats;
@@ -109,4 +109,34 @@
 	}
 
+	# calculate a 3-sigma clipped mean (if Nvalues > 8, reject > 3sigma outliers)
+	if ($type eq "clipmean") {
+            if (scalar @$data > 0) {
+		# Get statistics on the value
+		my $stats = Statistics::Descriptive::Sparse->new(); # Statistics calculator
+		$stats->add_data(@$data);
+		my $rawMean = $stats->mean();
+		my $rawStdev = $stats->standard_deviation();
+		my $rawLimit = 3.0*$rawStdev;
+
+		# clip, if we can
+		if (scalar @$data > 8) {
+		    my @clipdata = ();
+		    foreach my $value (@$data){ 
+			my $delta = abs($value - $rawMean);
+			if ($delta > $rawLimit) { next; }
+			push @clipdata, $value;
+		    }
+		    my $clipstats = Statistics::Descriptive::Sparse->new(); # Statistics calculator
+		    $clipstats->add_data(@clipdata);
+		    $entry->{value} = $clipstats->mean();
+		} else {
+		    $entry->{value} = $stats->mean();
+		}
+	    } else {
+		$self->_null_for_type ($entry);
+	    }
+	    next;
+	}
+
 	if ($type eq "stdev") {
             if (scalar @$data > 1) {
@@ -122,4 +152,34 @@
 	    } 
 	    $self->_null_for_type ($entry);
+	    next;
+	}
+
+	# calculate a 3-sigma clipped stdev (if Nvalues > 8, reject > 3sigma outliers)
+	if ($type eq "clipstdev") {
+            if (scalar @$data > 0) {
+		# Get statistics on the value
+		my $stats = Statistics::Descriptive::Sparse->new(); # Statistics calculator
+		$stats->add_data(@$data);
+		my $rawMean = $stats->mean();
+		my $rawStdev = $stats->standard_deviation();
+		my $rawLimit = 3.0*$rawStdev;
+
+		# clip, if we can
+		if (scalar @$data > 8) {
+		    my @clipdata = ();
+		    foreach my $value (@$data){ 
+			my $delta = abs($value - $rawMean);
+			if ($delta > $rawLimit) { next; }
+			push @clipdata, $value;
+		    }
+		    my $clipstats = Statistics::Descriptive::Sparse->new(); # Statistics calculator
+		    $clipstats->add_data(@clipdata);
+		    $entry->{value} = $clipstats->standard_deviation();
+		} else {
+		    $entry->{value} = $stats->standard_deviation();
+		}
+	    } else {
+		$self->_null_for_type ($entry);
+	    }
 	    next;
 	}
@@ -270,5 +330,15 @@
 	    }
 
+	    if ($type eq 'clipmean') {
+		push @$data, $value;
+		next;
+	    }
+
 	    if ($type eq 'stdev') {
+		push @$data, $value;
+		next;
+	    }
+
+	    if ($type eq 'clipstdev') {
 		push @$data, $value;
 		next;