Changeset 9524 for trunk/ippScripts/scripts/detrend_process_exp.pl

Timestamp:

Oct 12, 2006, 2:00:09 PM (20 years ago)

Author:

Paul Price

Message:

Using correct statistics: mean is mean of the background, stdev is the global stdev (\sum s_i^{2) / N, mean stdev is the stdev of the means.}

File:

• trunk/ippScripts/scripts/detrend_process_exp.pl (modified) (3 diffs)

trunk/ippScripts/scripts/detrend_process_exp.pl

@@ -61 +61 @@
 {
     my @backgrounds;            # Array of backgrounds in each component
-    my @stdevs;                 # Array of standard deviations in each component
+    my @variances;    # Array of variances for each component
     foreach my $file (@$files) {
         die "Unable to find class id\n" unless defined $file->{class_id};
@@ -68 +68 @@
         die "Unable to find bg_mean_stdev for class_id=$class_id\n" unless defined $file->{bg_mean_stdev};
         push @backgrounds, $file->{bg};
-        push @stdevs, $file->{bg_mean_stdev};
+        push @variances, $file->{bg_stdev}**2;
     }
 
@@ -75 +75 @@
         $stats->add_data(@backgrounds);
         $bg = $stats->mean();
-        if (scalar @backgrounds == 1) {
-            $bg_stdev = 0.0;
-        } else {
-            $bg_stdev = $stats->standard_deviation();
-        }
+        $bg_mean_stdev = $stats->standard_deviation() || 0.0;
     }
     {
         my $stats = Statistics::Descriptive::Sparse->new; # Statistics calculator
-        $stats->add_data(@stdevs);
-        $bg_mean_stdev = $stats->mean();
+        $stats->add_data(@variances);
+        $bg_stdev = sqrt( $stats->mean() );
     }
 }