statistics: added a script that outputs the min, max and average tree sizes of a given input file

statistics/nodes_per_tree.sh

+#!/bin/bash
+# file: nodes_per_tree.sh
+#
+# usage: ./prepare_data.sh <inputfile>
+#
+# Program: Counts the number of nodes per line. Ouputs the maximal, 
+#          minimal and average number of nodes per line of the given 
+#          inputfile containing a tree in bracket notation per line.
+#
+# Author: Thomas Huetter
+
+if [ -z "$1" ]
+  then
+    echo "Argument missing."
+    echo "Usage: ./prepare_data.sh <inputfile>"
+    exit 1
+fi
+
+awk -F '\{' '{print NF-1}' $1 | awk 'NR == 1 { max=$1; min=$1; sum=0 }
+   { if ($1>max) max=$1; if ($1<min) min=$1; sum+=$1;}
+   END {printf "Min: %d\tMax: %d\tAverage: %f\n", min, max, sum/NR}'