#!/usr/bin/perl
#

  
# plot displacement vs. time
  my($output_file, $term_options);

  $output_file = "twocar_displ.ps";
  $term_options = "postscript color enhanced 'Helvetica,18' ";

  $cmdfile = "gnuplot.in";
  
  open (CMDFILE, ">$cmdfile") || die("can't open $cmdfile for writing");
  printf CMDFILE "set output '$output_file' \n";
  printf CMDFILE "set term $term_options \n";

  #  revert to some oldish default colors 
  printf CMDFILE "set style line 1 lt rgb 'red' lw 3  \n"; 
  printf CMDFILE "set style line 2 lt rgb 'sea-green' lw 3  \n"; 
  printf CMDFILE "set style line 3 lt rgb 'blue' lw 3  \n"; 
  printf CMDFILE "set style line 4 lt rgb 'cyan' lw 3  \n"; 
  printf CMDFILE "set style line 5 lt rgb 'violet' lw 3  \n"; 




  printf CMDFILE "set grid \n";
  printf CMDFILE "set key top left \n";
  printf CMDFILE "set xlabel 'Time after car B hits the brakes (s)' \n";
  printf CMDFILE "set ylabel 'Displacement (m) ' \n";


  $cmd = "plot [0:9.0][0:120]  ";
  $cmd .= "   './twocar_calc.out' using 1:2 with lines ls 1 lw 5 t 'car A' ";
  $cmd .= " , ";
  $cmd .= "   './twocar_calc.out' using 1:4 with lines ls 3 lw 5 t 'car B' ";

  printf CMDFILE "$cmd \n";
  printf CMDFILE "set output \n";
  printf CMDFILE "quit \n";
  close(CMDFILE) ;
  
  $retval = `gnuplot < $cmdfile`;
  printf "retval is ..%s..\n", $retval;
  
  if ($term_options =~ /postscript/) {
    $psfile = $output_file;
    $giffile = $psfile;
    $giffile =~ s/.ps/.png/;
    $cmd = "convert -rotate 90 $psfile $giffile";
    printf "cmd is ..$cmd.. \n";
    $ret = `$cmd`;
  }


  
# plot position from A's initial position vs. time
  my($output_file, $term_options);

  $output_file = "twocar_pos.ps";
  $term_options = "postscript color enhanced 'Helvetica,18' ";

  $cmdfile = "gnuplot.in";
  
  open (CMDFILE, ">$cmdfile") || die("can't open $cmdfile for writing");
  printf CMDFILE "set output '$output_file' \n";
  printf CMDFILE "set term $term_options \n";

  #  revert to some oldish default colors 
  printf CMDFILE "set style line 1 lt rgb 'red' lw 3  \n"; 
  printf CMDFILE "set style line 2 lt rgb 'sea-green' lw 3  \n"; 
  printf CMDFILE "set style line 3 lt rgb 'blue' lw 3  \n"; 
  printf CMDFILE "set style line 4 lt rgb 'cyan' lw 3  \n"; 
  printf CMDFILE "set style line 5 lt rgb 'violet' lw 3  \n"; 




  printf CMDFILE "set grid \n";
  printf CMDFILE "set key top left \n";
  printf CMDFILE "set xlabel 'Time after car B hits the brakes (s)' \n";
  printf CMDFILE "set ylabel 'Distance from big tree (m) ' \n";


  $cmd = "plot [0:9.0][0:120]  ";
  $cmd .= "   './twocar_calc.out' using 1:2 with lines ls 1 lw 5 t 'car A' ";
  $cmd .= " , ";
  $cmd .= "   './twocar_calc.out' using 1:(\$4+53.0) with lines ls 3 lw 5 t 'car B' ";

  printf CMDFILE "$cmd \n";
  printf CMDFILE "set output \n";
  printf CMDFILE "quit \n";
  close(CMDFILE) ;
  
  $retval = `gnuplot < $cmdfile`;
  printf "retval is ..%s..\n", $retval;
  
  if ($term_options =~ /postscript/) {
    $psfile = $output_file;
    $giffile = $psfile;
    $giffile =~ s/.ps/.png/;
    $cmd = "convert -rotate 90 $psfile $giffile";
    printf "cmd is ..$cmd.. \n";
    $ret = `$cmd`;
  }


  
# plot velocity vs. time

  $output_file = "twocar_vel.ps";
  $term_options = "postscript color enhanced 'Helvetica,18' ";

  $cmdfile = "gnuplot.in";
  
  open (CMDFILE, ">$cmdfile") || die("can't open $cmdfile for writing");
  printf CMDFILE "set output '$output_file' \n";
  printf CMDFILE "set term $term_options \n";

  #  revert to some oldish default colors 
  printf CMDFILE "set style line 1 lt rgb 'red' lw 3  \n"; 
  printf CMDFILE "set style line 2 lt rgb 'sea-green' lw 3  \n"; 
  printf CMDFILE "set style line 3 lt rgb 'blue' lw 3  \n"; 
  printf CMDFILE "set style line 4 lt rgb 'cyan' lw 3  \n"; 
  printf CMDFILE "set style line 5 lt rgb 'violet' lw 3  \n"; 




  printf CMDFILE "set grid \n";
  printf CMDFILE "set key top right \n";
  printf CMDFILE "set xlabel 'Time after car B hits the brakes (s)' \n";
  printf CMDFILE "set ylabel 'Velocity (m/s) ' \n";


  $cmd = "plot [0:9.0][0:30]  ";
  $cmd .= "   './twocar_calc.out' using 1:3 with lines ls 1 lw 5 t 'car A' ";
  $cmd .= " , ";
  $cmd .= "   './twocar_calc.out' using 1:5 with lines ls 3 lw 5 t 'car B' ";

  printf CMDFILE "$cmd \n";
  printf CMDFILE "set output \n";
  printf CMDFILE "quit \n";
  close(CMDFILE) ;
  
  $retval = `gnuplot < $cmdfile`;
  printf "retval is ..%s..\n", $retval;
  
  if ($term_options =~ /postscript/) {
    $psfile = $output_file;
    $giffile = $psfile;
    $giffile =~ s/.ps/.png/;
    $cmd = "convert -rotate 90 $psfile $giffile";
    printf "cmd is ..$cmd.. \n";
    $ret = `$cmd`;
  }



exit 0;