awk ' BEGIN {
  printf"  Determination du facteur d echelle\n\n"
  printf"  No      X1      Y1      X2      Y2      DX      DY\n\n"
}
{
dix=$2/$4
diy=$3/$5
printf" %04d %7.2f %7.2f %7.2f %7.2f %7.2f %7.2f\n",$1,$2,$3,$4,$5,dix,diy
dx[NR]=dix
dy[NR]=diy
dxt += dix
dyt += diy
}
END {
dxm = dxt / NR
dym = dyt / NR

for (i=1;i<NR;i++) {
difx = dxm - dx[i]
dify = dym - dy[i]
diffx += difx
diffy += dify
difgx += (difx * difx)
difgy += (dify * dify)
}
 
ectx=sqrt((difgx - diffx * diffx / NR) / (NR-1))
ecty=sqrt((difgy - diffy * diffy / NR) / (NR-1))
printf "\n moyenne = %7.3f %7.3f\n",dxm,dym
printf " Ecarts  = %7.3f %6.3f\n\n",ectx,ecty
} '