#!/usr/bin/awk -f BEGIN { init = 0; count = 0; sum = 0; sum2 = 0; } /^[0-9]+\.[0-9]+/ { if(init != 0) { count = count + 1; target = init + count * 0.1; delta = $1 - target; if(delta < 0) delta = -delta; sum = sum + delta; sum2 = sum2 + delta * delta; } else { init = $1; } } END { avg = sum / count; var = sum2 / count - avg * avg; print count " samples: average = " avg "; variance = " var; }