Add stats.sh for simple stats functions

include/stats.sh

@@ -0,0 +1,43 @@
+#!/bin/bash
+
+
+average() {
+    #
+    # Get the average from numbers (one number per line)
+    #
+    perl -e '
+        my $cnt = $sum = 0;
+        while (<>) {
+            next unless /\d+/;
+            $cnt += 1;
+            $sum += $_;
+        }
+        print $sum / $cnt;
+        print "\n";
+    '
+}
+
+
+trim() {
+    #
+    # Remove statistical error by trimming
+    #
+    # sort numbers and throw away $1 % of biggest
+    # and same no. of smallest items
+    #
+    local pct=${1:-10}
+    local tmp=$(mktemp)
+    cat > $tmp
+    local c_all=$(cat $tmp | wc -l)
+    debug -v c_all pct
+    set -x
+    local offset=$(( ( c_all * $pct ) / 100 ))
+    set +x
+    debug -v offset
+    cat $tmp \
+        | sort -g \
+        | head -n -$offset \
+        | tail -n +$((offset + 1))
+    rm -f $tmp
+}
+