#!/usr/bin/perl

sub usage
{
	print STDERR "usage: $0 [-i] [log_file]\n";
	exit(1);
}


$with = "steps";
if ($ARGV[0] eq "-i") {
	shift @ARGV;
	$with = "lines";
}
&usage if $ARGV[0] =~ /^-/;

$n = 1;
while (<>) {
	next unless /^=== (\d+) ===/;
	while ($1 != $n) {
		push(@f, $n);
		$n++;
	}
	$n++;
}

$n--;
$f = int($n/@f+0.5);

$last = 0;
for (@f) {
	push(@d, $_-$last);
	$last = $_;
}

$cmd = "|gnuplot -e '".
    'set term postscript color eps enhanced solid lw 2 20;'.
    'set output "out.eps";'.
    'set title "Probability distribution of time between NOR corruptions";'.
    'set xlabel "Power cycles";'.
    'set ylabel "Cumulative probability";'.
    'set key bottom;'.
    'plot "-" with '.$with.' title "Empirical distribution (N='.@f.')", '.
      '1-exp(-'.1/$f.'*x) with lines lt 3 '.
      'title "Exponential distribution ({/Symbol l}=1/'.$f.')"'.
    "'";

open(PIPE, $cmd) || die "open: $!";
print PIPE "0 0\n";
$i = 0;
for (sort { $a <=> $b } @d) {
	$i++;
	print PIPE $_, " ", $i/@f, "\n";
}
close(PIPE) || die "close: $!";

system("cat out.eps | ".
    "gs -sDEVICE=ppmraw -r100 -sOutputFile=- ".
    "-dTextAlphaBits=4 -dGraphicsAlphaBits=4 -sPAPERSIZE=a4 -q - | ".
    "convert -trim - out.png");
unlink("out.eps");