#!/bin/csh
alias echo "echo > /dev/null"
kappa
unalias echo

echo " "
echo " ***************************** "
echo " *  Calc % Pol and Angle     * "
echo " *  From I, Q, U aperture    * "
echo " *  photometry measurements  * "
echo " ***************************** "
echo " "

echo " Notes... "
echo "  - Display I, Q and U images in Gaia "
echo "  - Use aperture photom (result in counts) "
echo "    with option - 'keep apertures same' and "
echo "    parameters - 'centroid' switched off "
echo "  - Enter values below..."

loop1:
echo " "
echo -n " >>> I in counts: "
  set I="$<"
echo -n " >>> Q in counts: "
  set Q="$<"
echo -n " >>> U in counts: "
  set U="$<"

  set a = `calc exp="'( ($Q)*($Q)+($U)*($U) )/( ($I)*($I) )'"`
  set P = `calc exp="'(sqrt($a))*100'"`

# IF (and indeed all cshell commands) only work on integers
  set QIN = `calc exp=$Q prec=_integer`
  set UIN = `calc exp=$U prec=_integer`

  set b = `calc exp="'atand(($U)/($Q))'"`
  if ($QIN < 0) then 
    set TH =  `calc exp="'(($b) + 180)/2.0'"`
  else if ($QIN > 0 && $UIN < 0) then 
    set TH =  `calc exp="'(($b) + 360)/2.0'"`
  else 
    set TH =  `calc exp="'($b)/2.0'"`
  endif

  echo " "
  echo " some math..."
  echo " a          = " $a
  echo " b          = " $b
  echo " q - integ  = " $QIN
  echo " u - integ  = " $UIN
  echo " "

echo " "
echo " Results: "
echo " -------- "
echo " *** I     =  ${I} "
echo " *** Q     =  ${Q} "
echo " *** U     =  ${U} "
echo " *** P     =  ${P} % "
echo " *** Theta =  ${TH} degrees"
echo " "

echo " "
echo -n " Calculate for another target...(y/n)? "
   set answr="$<"
     if ($answr == "Y" || $answr == "y") then
       goto loop1
     endif

echo " "