#!/bin/csh -f
#
# extracterr - extract one column, plus error, of a set of data files 
#
# usage:
#   extracterr col file.data-a ...
# 
#  Three columns are output: avg, avg-stddev, avg+stddev.
# One line per data file. 
#  These could be used to make an error-bar plot. 

if ($#argv < 2) then
    echo usage: 'extracterr col file.data-a ...'
    exit 1
endif

set col=$1
shift

Awk 'NR%2==1 {avg=$'$col'}\
     NR%2==0 {print avg, avg-$'$col', avg+$'$col'}' $*

