#!/usr/bin/env perl
#
#    Copyright (C) 2020 Genome Research Ltd.
#
#    Author: James Bonfield <jkb@sanger.ac.uk>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
# DEALINGS IN THE SOFTWARE.

# Note: this script requires gnuplot version 5.0 or later.

use strict;
use Getopt::Long;
use List::Util qw(max);
use POSIX qw(ceil);

my $version = "1.0";

#-----------------------------------------------------------------------------
# Command line argument handling & help

my %opts;

my $res = GetOptions("size=s"      => \$opts{size},
                     "size2=s"     => \$opts{size2},
                     "size3=s"     => \$opts{size3},
                     "help"        => \$opts{help},
                     "page=i"      => \$opts{page},
                     "amp_add=i"   => \$opts{amp_add},
                     "amp-add=i"   => \$opts{amp_add},
                     "orient=s"    => \$opts{orient},
                     "depth_max=s" => \$opts{depth_max},
                     "depth-max=s" => \$opts{depth_max},
                     "thumbnails"  => \$opts{thumbnails},
                     "thumb_size=i"=> \$opts{thumb_size},
                     "thumb-size=i"=> \$opts{thumb_size},
                     "index-only"  => \$opts{index_only});

$opts{size}      = "1000,800" unless $opts{size};
$opts{size2}     = "1000,400" unless $opts{size2};
$opts{size3}     = "400,847"  unless $opts{size3};
$opts{page}      = 96         unless $opts{page};
$opts{amp_add}   = 100        unless $opts{amp_add};
$opts{orient}    = "h"        unless $opts{orient};
$opts{depth_max} = 0          unless $opts{depth_max};
$opts{thumbnails}= 0          unless $opts{thumbnails};
$opts{thumb_size}= 200        unless $opts{thumb_size};

my $max_depth = 0;

my $usage = <<END;
plot-ampliconstats version $version

Usage: plot-ampliconstats prefix [FILE]

Options:
    -help         Show this usage
    -size  W,H    Set image width to W and height to H for heatmaps
    -size2 W,H    Set image width to W and height to H for graphs (horizontal)
    -size3 W,H    Set image width to W and height to H for graphs (vertical)
    -page N       Maximum number of samples per page in heatmaps
    -amp-add X    Small sample fudge: NErr/(NAll+X) in amplicon count plots
    -orient h/v   Orientation for plots, defaults to h (horizontal)
    -depth-max N  Force -reads.png plots to have a fixed yrange
    -thumbnails   Produce scaled down thumbnail images
    -thumb-size N Display thumbnails as N pixels wide.

If FILE is not specified, reads from stdin.
END

if ($res != 1 or $opts{help} or scalar(@ARGV) < 1) {
    print $usage;
    exit 0;
}

my $prefix = shift(@ARGV);

# Useful for debugging, but undocumented
goto index_only if ($opts{index_only});

#-----------------------------------------------------------------------------
# Check gnuplot version.
#
# We need >= 5.0 in order to cope with "matrix rowheaders" command.
my $g=`gnuplot --version` || die "gnuplot: $!";
$g=~m/gnuplot ([\d.]+)/;
if ($1 < 5) {
    print STDERR "Plot-ampliconstats needs gnuplot version 5.0 or later (found $1)\n";
    exit 1;
}

#-----------------------------------------------------------------------------
# Load plot meta-data
# This allows us to auto-scale plots.
my $namp = 0;
my $nfile = 0;
my $ref_len = 0;
while (<>) {
    chomp($_);
    my @F = split("\t", $_);
    $namp  = $F[2] if (/^SS\tNumber of amplicons/);
    $nfile = $F[2] if (/^SS\tNumber of files/);
    $ref_len = $F[2] if (/^SS\tReference length/);
    last if (/^SS\tEnd of summary/);
}

#-----------------------------------------------------------------------------
# Open up our various gnuplot output files

# TODO: When nfile is too large we will need to paginate and produce
# multiple plots in a for loop.  This may change the structure of this
# code with the headers being printed inline with the processing loop
# below.

my $xfont = ($namp >= 100) ? 8 : 13;
my $yfont = ($nfile >= 80) ? 5 : 8;
my $impw1 = ($namp >= 100) ? 4 : 5;
my $impw2 = ($namp >= 100) ? 2 : 4;

#--- Combined
open(my $ch_depth, ">", $prefix."-combined-depth.gp") ||
    die "$prefix-combined-depth.gp";

open(my $ch_reads, ">", $prefix."-combined-reads.gp") ||
    die "$prefix-combined-reads.gp";

open(my $ch_rperc, ">", $prefix."-combined-read-perc.gp") ||
    die "$prefix-combined-read-perc.gp";
if ($opts{orient} eq "h") {
    print $ch_rperc <<"END";
set title "Distribution percentage of reads across amplicons, all files"
set xlabel "amplicon"
set xrange [0:$namp+1]
set ylabel "percentage of reads"
set yrange [0:*]
set key below
set title font "helvetica,20"
set xtics 5 font "helvectica,$xfont" scale -2,-1
set mxtics 5
set terminal png size $opts{size2}
set output "$prefix-combined-read-perc.png"
plot "-" using (column(0)+1):1 with impulses lw $impw1      title "mean",\\
     "-" using (column(0)+1):1 with impulses lw $impw2 lt 3 title "s.d."
END
} else {
    print $ch_rperc <<"END";
set title "Read distribution, all files"
set ylabel "amplicon"
set yrange [0:$namp+1]
set xlabel "percentage of reads"
set xrange [0:*]
set grid; # xtics noytics
set key below
set title font "helvetica,20"
set ytics 5 font "helvectica,$xfont" scale -2,-1
set mytics 5
set terminal png size $opts{size3}
set output "$prefix-combined-read-perc.png"
plot "-" using (0):(column(0)+1):1:(0) with vector nohead lw $impw1      title "mean",\\
     "-" using (0):(column(0)+1):1:(0) with vector nohead lw $impw2 lt 3 title "s.d."
END
}

open(my $ch_amp, ">", $prefix."-combined-amp.gp") ||
    die "$prefix-combined-amp.gp";
if ($opts{orient} eq "h") {
    print $ch_amp <<"END";
set title "Percentage of read-pairs with incorrectly positioned primers, all files"
set xlabel "amplicon"
set xrange [0:$namp+1]
set ylabel "percentage of reads"
set yrange [0:*]
unset key
set title font "helvetica,20"
set xtics 5 font "helvectica,$xfont" scale -2,-1
set mxtics 5
set terminal png size $opts{size2}
set output "$prefix-combined-amp.png"
plot "-" using (column(0)+1):1 with impulses lw $impw1
END
} else {
    print $ch_amp <<"END";
set title "% mis-priming, all files"
set ylabel "amplicon"
set yrange [0:$namp+1]
set xlabel "percentage of reads"
set xrange [0:*]
unset key
set grid
set title font "helvetica,20"
set ytics 5 font "helvectica,$xfont" scale -2,-1
set mytics 5
set terminal png size $opts{size3}
set output "$prefix-combined-amp.png"
plot "-" using (0):(column(0)+1):1:(0) with vector nohead lw $impw1
END
}

my $fh_reads;
my $fh_reads_count = 0;
my $fh_reads_page = 1;
my $fh_reads_nfile = 0;

my $fh_depth;
my $fh_depth_count = 0;
my $fh_depth_page = 1;
my $fh_depth_nfile = 0;

my $fh_amp;
my $fh_amp_count = 0;
my $fh_amp_page = 1;
my $fh_amp_nfile = 0;

my ($fh_rperc, $fh_rperl);
my $fh_rperc_count = 0;
my $fh_rperc_page = 1;
my $fh_rperc_nfile = 0;

my %fh_cover; # For coverage at multiple different depths
my %fh_cover_count;
my %fh_cover_page;
my %fh_cover_nfile;

my @amp_start; # coords for amplicons
my @amp_end;

#-----------------------------------------------------------------------------
# Parse stats file, writing to a number of outputs simultaneously
my %file;
my $fh;
my @combined_coord;
while (<>) {
    chomp($_);
    my @F = split("\t", $_);

    # Amplicon coordinates
    if (/^AMPLICON/) {
        my $min_left=1e9;
        foreach (split(",",$F[2])) {
            /\d+-(\d+)/;
            $min_left=$1 if ($min_left > $1);
        }
        my $max_right=0;
        foreach (split(",",$F[3])) {
            /(\d+)-\d+/;
            $max_right=$1 if ($max_right < $1);
        }
        $amp_start[$F[1]]=$min_left;
        $amp_end[$F[1]]=$max_right;

        $ref_len = $max_right if ($ref_len < $max_right);
    }

    # Heatmaps showing all files & all amplicons
    local $"="\t";
    my $name=$F[1];
    $name =~ s/_/\\\\_/g if (/^F/);
    $name =~ s/"/\\\\"/g if (/^F/);

    # Initialise gnuplot files as we create new pages
    #----------  Heatmap READS

    $fh_reads_count++ if (/^FREADS/);
    if ($fh_reads_count > $opts{page} && $nfile-$opts{page}*$fh_reads_page!=1) {
        print STDERR "page $fh_reads_page\n";
        if (defined($fh_reads)) {
            print $fh_reads "\nend\n";
            close($fh_reads);
            system("gnuplot", "$prefix-heat-reads-$fh_reads_page.gp") && die;
            undef $fh_reads;
        }
        $fh_reads_page++;
        $fh_reads_count = 0;
    }

    if (/^FREADS/ && !defined($fh_reads)) {
        $fh_reads_nfile = $fh_reads_page * $opts{page} > $nfile
            ? $nfile - ($fh_reads_page-1) * $opts{page}
            : $opts{page};
        $fh_reads_nfile++ if ($fh_reads_page * $opts{page} == $nfile-1);
        open($fh_reads, ">", $prefix."-heat-reads-$fh_reads_page.gp") ||
            die "$prefix-heat-reads-$fh_reads_page.gp";
        print $fh_reads <<"END";
set title "average number of log10(reads) per amplicon, page $fh_reads_page"
unset key
set xrange [:$namp+1]
set yrange [-1:$fh_reads_nfile]
set bmargin at screen 0.07
set tmargin at screen 0.91
#set palette rgbformula 15,4,9
set palette rgbformula 32,31,30
set cbrange [0:6]
set title font "helvetica,20"
set xtics 5 font "helvectica,$xfont" scale -0.8,-0.4
set mxtics 5
set ytics font "helvetica,5" scale -0.4
set terminal png size $opts{size}
set output "$prefix-heat-reads-$fh_reads_page.png"
set view map
splot "-" using (\$1+1):2:(\$3>0?log10(\$3):0) matrix rowheaders with image
END
    }
    print $fh_reads "\"$name\"\t@F[2..$#F]\n" if (/^FREADS/);


    #----------  Heatmap DEPTH
    $fh_depth_count++ if (/^FDEPTH/);
    if ($fh_depth_count > $opts{page}
        && $nfile-$opts{page}*$fh_depth_page != 1) {
        if (defined($fh_depth)) {
            print $fh_depth "\nend\n";
            close($fh_depth);
            system("gnuplot", "$prefix-heat-depth-$fh_depth_page.gp") && die;
            undef $fh_depth;
        }
        $fh_depth_page++;
        $fh_depth_count = 0;
    }

    if (/^VDEPTH/ && !defined($fh_depth)) {
        $fh_depth_nfile = $fh_depth_page * $opts{page} > $nfile
            ? $nfile - ($fh_depth_page-1) * $opts{page}
            : $opts{page};
        $fh_depth_nfile++ if ($fh_depth_page * $opts{page} == $nfile-1);
        open($fh_depth, ">", $prefix."-heat-depth-$fh_depth_page.gp") ||
            die "$prefix-heat-depth-$fh_depth_page.gp";
        print $fh_depth <<"END";
set title "average log10(depth) per amplicon, page $fh_depth_page"
unset key
set xrange [0:$namp+1]
set yrange [-1:$fh_depth_nfile]
set bmargin at screen 0.07
set tmargin at screen 0.91
set palette rgbformula 15,4,9
set cbrange [0:6]
set title font "helvetica,20"
set xtics 5 font "helvectica,$xfont" scale -0.8,-0.4
set mxtics 5
set ytics font "helvetica,5" scale -0.4
set terminal png size $opts{size}
set output "$prefix-heat-depth-$fh_depth_page.png"
set view map
splot "-" using (\$1+1):2:(\$3>0?log10(\$3):0) matrix rowheaders with image
END
    }
    print $fh_depth "\"$name\"\t@F[2..$#F]\n" if (/^VDEPTH/);


    #----------  Heatmap AMP mismatch
    $fh_amp_count++ if (/^FAMP\t\S+\t0/);
    if ($fh_amp_count > $opts{page} && $nfile-$opts{page}*$fh_amp_page!=1) {
        if (defined($fh_amp)) {
            print $fh_amp "\nend\n";
            close($fh_amp);
            system("gnuplot", "$prefix-heat-amp-$fh_amp_page.gp") && die;
            undef $fh_amp;
        }
        $fh_amp_page++;
        $fh_amp_count = 0;
    }

    if (/^FAMP/ && !defined($fh_amp)) {
        $fh_amp_nfile = $fh_amp_page * $opts{page} > $nfile
            ? $nfile - ($fh_amp_page-1) * $opts{page}
            : $opts{page};
        $fh_amp_nfile++ if ($fh_amp_page * $opts{page} == $nfile-1);
        open($fh_amp, ">", $prefix."-heat-amp-$fh_amp_page.gp") ||
            die "$prefix-heat-amp-$fh_amp_page.gp";
        print $fh_amp <<"END";
set title "Percentage of read-pairs with incorrectly positioned primers, page $fh_amp_page"
unset key
set xrange [0:$namp+1]
set yrange [-1:$fh_amp_nfile]
set bmargin at screen 0.07
set tmargin at screen 0.91
set palette rgbformula 30,31,32
set cbrange [0:100]
set title font "helvetica,20"
set xtics 5 font "helvectica,$xfont" scale -0.8,-0.4
set mxtics 5
set ytics font "helvetica,5" scale -0.4
set terminal png size $opts{size}
set output "$prefix-heat-amp-$fh_amp_page.png"
set view map
splot "-" using (\$1+1):2:3 matrix rowheaders with image
END
    }
    if (/^FAMP/) {
        if ($F[2] == 0) {
            # First line will be summary across all amplicons (amp 0)
            if ($fh_amp_count == 0) {
                print $fh_amp "\"$name\"";
            } else {
                print $fh_amp "\n\"$name\"";
            }
        } else {
            # Subsequent lines are per amplicon stats,
            # corrected for small sample size via amp_add.
            print $fh_amp "\t", 100*($F[4]+$F[5])/($F[3]+$F[4]+$F[5]+$opts{amp_add});
        }
    }


    #----------  Heatmap READ-PERC, clipped and log
    $fh_rperc_count++ if (/^FRPERC/);
    if ($fh_rperc_count > $opts{page}
        && $nfile-$opts{page}*$fh_rperc_page != 1) {
        if (defined($fh_rperc)) {
            print $fh_rperc "\nend\n";
            close($fh_rperc);
            system("gnuplot", "$prefix-heat-read-perc-$fh_rperc_page.gp") && die;
            undef $fh_rperc;
        }
        if (defined($fh_rperl)) {
            print $fh_rperl "\nend\n";
            close($fh_rperl);
            system("gnuplot", "$prefix-heat-read-perc-log-$fh_rperc_page.gp") && die;
            undef $fh_rperl;
        }
        $fh_rperc_page++;
        $fh_rperc_count = 0;
    }

    if (/^FRPERC/ && !defined($fh_rperc)) {
        $fh_rperc_nfile = $fh_rperc_page * $opts{page} > $nfile
            ? $nfile - ($fh_rperc_page-1) * $opts{page}
            : $opts{page};
        $fh_rperc_nfile++ if ($fh_rperc_page * $opts{page} == $nfile-1);

        open($fh_rperc, ">", $prefix."-heat-read-perc-$fh_rperc_page.gp") ||
            die "$prefix-heat-read-perc-$fh_rperc_page.gp";
        print $fh_rperc <<"END";
set title "percentage of reads per amplicon (max 5%), page $fh_rperc_page
unset key
set xrange [0:$namp+1]
set yrange [-1:$fh_rperc_nfile]
set bmargin at screen 0.07
set tmargin at screen 0.91
#set palette rgbformula 6,5,13
set palette rgbformula 30,31,32
set cbrange [0:5]
set title font "helvetica,20"
set xtics 5 font "helvectica,$xfont" scale -0.8,-0.4
set mxtics 5
set ytics font "helvetica,5" scale -0.4
set terminal png size $opts{size}
set output "$prefix-heat-read-perc-$fh_rperc_page.png"
set view map
splot "-" using (\$1+1):2:(\$3<5?\$3:5) matrix rowheaders with image
END

        open($fh_rperl, ">", $prefix."-heat-read-perc-log-$fh_rperc_page.gp") ||
            die "$prefix-heat-read-perc-log-$fh_rperc_page.gp";
        print $fh_rperl <<"END";
set title "percentage of reads per amplicon (log10 scale), page $fh_rperc_page
unset key
set xrange [0:$namp+1]
set yrange [-1:$fh_rperc_nfile]
set bmargin at screen 0.07
set tmargin at screen 0.91
#set palette rgbformula 6,5,13
set palette rgbformula 30,31,32
set cbrange [-1:2]
set title font "helvetica,20"
set xtics 5 font "helvectica,$xfont" scale -0.8,-0.4
set mxtics 5
set ytics font "helvetica,5" scale -0.4
set terminal png size $opts{size}
set output "$prefix-heat-read-perc-log-$fh_rperc_page.png"
set view map
splot "-" using (\$1+1):2:(\$3>0?log10(\$3):0) matrix rowheaders with image
END
    }
    print $fh_rperc "\"$name\"\t@F[2..$#F]\n" if (/^FRPERC/);
    print $fh_rperl "\"$name\"\t@F[2..$#F]\n" if (/^FRPERC/);
    
    #----------  Heatmap COVERAGE at multiple depths
    $fh_cover_count{$1}++ if (/^FPCOV-(\d+)/);
    if ($fh_cover_count{$1} > $opts{page}
        && $nfile-$opts{page}*$fh_cover_page{$1} != 1) {
        if (defined($fh_cover{$1})) {
            my $tmp = $fh_cover{$1};
            print $tmp "\nend\n";
            close($fh_cover{$1});
            system("gnuplot", "$prefix-heat-coverage-$1-$fh_cover_page{$1}.gp") && die;
            undef $fh_cover{$1};
        }
        $fh_cover_page{$1}++;
        $fh_cover_count{$1} = 0;
    }

    if (/^FPCOV-(\d+)\t/) {
        $fh_cover_page{$1}=1 if !defined($fh_cover_page{$1});
        $fh_cover_nfile{$1} = $fh_cover_page{$1} * $opts{page} > $nfile
            ? $nfile - ($fh_cover_page{$1}-1) * $opts{page}
            : $opts{page};
        $fh_cover_nfile{$1}++ if ($fh_cover_page{$1} * $opts{page}==$nfile-1);
        if (!defined($fh_cover{$1})) {
            open($fh_cover{$1}, ">", $prefix."-heat-coverage-$1-$fh_cover_page{$1}.gp") ||
                die "$prefix-heat-coverage-$1-$fh_cover_page{$1}.gp";
            my $tmp = $fh_cover{$1};
            print $tmp <<"END";
set title "percentage of amplicon covered to depth $1, page $fh_cover_page{$1}"
unset key
set xrange [0:$namp+1]
set yrange [-1:$fh_cover_nfile{$1}]
set bmargin at screen 0.07
set tmargin at screen 0.91
set palette rgbformula -13,6,-15
set cbrange [0:100]
set title font "helvetica,20"
set xtics 5 font "helvectica,$xfont" scale -0.8, -0.4
set mxtics 5
set ytics 5 font "helvetica,5" scale -0.4
#set grid xtics ytics
set terminal png size $opts{size}
set output "$prefix-heat-coverage-$1-$fh_cover_page{$1}.png"
set view map
splot "-" using (\$1+1):2:3 matrix rowheaders with image
END
        }
        my $tmp = $fh_cover{$1};
        print $tmp "\"$name\"\t@F[2..$#F]\n";
    }

    # Graphs with merged file data (mean and SD) for all amplicons
    local $"="\n";
    print $ch_reads "\$mean << EOD\n@F[2..$#F]\nEOD\n\n" if (/^CDEPTH.*MEAN/);
    print $ch_reads "\$sd << EOD\n@F[2..$#F]\nEOD\n\n" if (/^CDEPTH.*STDDEV/);
    print $ch_depth "\$mean << EOD\n@F[2..$#F]\nEOD\n\n" if (/^CDEPTH.*MEAN/);
    print $ch_depth "\$sd << EOD\n@F[2..$#F]\nEOD\n\n" if (/^CDEPTH.*STDDEV/);
    print $ch_rperc "@F[2..$#F]\nend\n" if (/^CRPERC.*(MEAN|STDDEV)/);
    print $ch_amp   100*($F[4]+$F[5])/($F[3]+$F[4]+$F[5]+$opts{amp_add}),"\n"
        if (/^CAMP\tCOMBINED\t[1-9]/);

    # These only occur once so we can open the file in situ rather
    # than keep appending to it.
    if (/^CPCOV-(\d+).*(MEAN|STDDEV)/) {
        # ASSUMPTION mean first, followed by stddev.
        # So open file for MEAN.  Close and plot on STDDEV
        if ($2 eq "MEAN") {
            open($fh, ">", $prefix."-combined-coverage-$1.gp") ||
                die "$prefix-combined-coverage-$1.gp";
            if ($opts{orient} eq "h") {
                print $fh <<"END";
set title "percentage of amplicon covered to depth >= $1, all files"
set xlabel "amplicon"
set xrange [0:$namp+1]
set ylabel "percent covered"
set yrange [0:100]
set key below
set title font "helvetica,20"
set xtics 5 font "helvectica,$xfont" scale -2,-1
set mxtics 5
set terminal pngcairo size $opts{size2}
set output "$prefix-combined-coverage-$1.png"
plot "-" using (column(0)+1):1 with impulses lw $impw1 lt 1 title "mean", \\
     "-" using (column(0)+1):1 with impulses lw $impw2 lt 3 title "s.d."
END
            } else {
                print $fh <<"END";
set title "%cover >=$1 deep, all files"
set ylabel "amplicon"
set yrange [0:$namp+1]
set xlabel "percent covered"
set xrange [0:100]
set grid
set key below
set title font "helvetica,20"
set ytics 5 font "helvectica,$xfont" scale -2,-1
set mytics 5
set terminal pngcairo size $opts{size3}
set output "$prefix-combined-coverage-$1.png"
plot "-" using (0):(column(0)+1):1:(0) with vector nohead lw $impw1 lt 1 title "mean", \\
     "-" using (0):(column(0)+1):1:(0) with vector nohead lw $impw2 lt 3 title "s.d."
END
            }
        }
        print $fh "@F[2..$#F]\nend\n";

        if ($2 eq "STDDEV") {
            close($fh);
            system("gnuplot", "$prefix-combined-coverage-$1.gp") && die;
        }
    }

    if (/^(FREADS|FDEPTH|FVDEPTH)/) {
        my $max = max(@F[2..$#F]);
        $max_depth = $max if $max_depth < $max;
    }

    # Per file graphs; accumulate multiple stats here and dump out at end
    if (/^(FREADS|FDEPTH|FVDEPTH|FPCOV|FRPERC)/) {
        $file{$F[1]}{$F[0]} = \@F;
        #push(@{$file{$F[1]}{keys}}, $F[0]);
    }
    if (/^FAMP\s\S+\s[1-9]*/) {
        push(@{$file{$F[1]}{$F[0]}}, 100*($F[4]+$F[5])/($F[3]+$F[4]+$F[5]+$opts{amp_add}));
    }
    if (/^FTCOORD/) {
        local $"="\t$F[2]\n";
        $_="@F[3..$#F]";
        s/,/\t/g;
        push(@{$file{$F[1]}{$F[0]}}, "$_\t$F[2]") if ($_ ne "");
    }

    if (/^CTCOORD/) {
        local $"="\t$F[2]\n";
        $_="@F[3..$#F]";
        s/,/\t/g;
        push(@combined_coord, "$_\t$F[2]") if ($_ ne "");
    }

    if(/^[FC]DP_(ALL|VALID)/) {
        local $"="\n";
        push(@{$file{$F[1]}{$F[0]}}, "@F[2..$#F]") if ($_ ne "");
    }
}

#-----------------------------------------------------------------------------
# Close gnuplot files and generate PNGs

#--- Per file
if (defined($fh_depth)) {
    print $fh_depth "\nend\n";
    close($fh_depth);
    system("gnuplot", "$prefix-heat-depth-$fh_depth_page.gp") && die;
}

if (defined($fh_amp)) {
    print $fh_amp "\nend\n";
    close($fh_amp);
    system("gnuplot", "$prefix-heat-amp-$fh_amp_page.gp") && die;
}

if (defined($fh_reads)) {
    print $fh_reads "\nend\n";
    close($fh_reads);
    system("gnuplot", "$prefix-heat-reads-$fh_reads_page.gp") && die;
}

if (defined($fh_rperc)) {
    print $fh_rperc "\nend\n";
    close($fh_rperc);
    system("gnuplot", "$prefix-heat-read-perc-$fh_rperc_page.gp") && die;
}

if (defined($fh_rperl)) {
    print $fh_rperl "\nend\n";
    close($fh_rperl);
    system("gnuplot", "$prefix-heat-read-perc-log-$fh_rperc_page.gp") && die;
}

foreach (keys %fh_cover) {
    if (defined($fh_cover{$_})) {
        close($fh_cover{$_});
        system("gnuplot", "$prefix-heat-coverage-$_-$fh_cover_page{$_}.gp") && die;
    }
}

#--- Combined
if ($opts{depth_max}) {
    if ($max_depth > $opts{depth_max}) {
        print STDERR "Warning: specified -depth_max is lower than the data maximum of $max_depth\n";
    }
    $max_depth = $opts{depth_max};
}
$max_depth = 10**ceil(log($max_depth+1)/log(10)); # round up to power of 10

# combined-reads
if ($opts{orient} eq "h") {
    print $ch_reads <<"END";
set title "average number of reads per amplicon, all files"
unset key
set xlabel "amplicon"
set xrange [0:$namp+1]
set ylabel "no. reads"
set yrange [1:$max_depth]
set logscale y
set key below
set title font "helvetica,20"
set xtics 5 font "helvetica,$xfont" scale -2,-1
set mxtics 5
set terminal png size $opts{size2}
set output "$prefix-combined-reads.png"
plot \$mean using (column(0)+1):(\$1 > 0.001 ? \$1 : 0.001) with impulses lw $impw1 title "mean", \\
     \$sd using (column(0)+1):(\$1 > 0.001 ? \$1 : 0.001) with impulses lw $impw2 lt 3 title "s.d."
END
} else {
    print $ch_reads <<"END";
# Compute max X value
stats \$mean nooutput
max_range = STATS_max
stats \$sd nooutput
max_range = max_range > STATS_max ? max_range : STATS_max
max_range = 10**ceil(log10(max_range+0.01))

set title "no. of reads, all files"
unset key
set ylabel "amplicon"
set yrange [0:$namp+1]
set xlabel "no. reads"
set xrange [0:max_range]
set grid; # xtics noytics
set logscale x
set format x "%.g"
set xtics font "helvectica,$yfont"
set key below
set title font "helvetica,20"
set ytics 5 font "helvectica,$xfont" scale -2,-1
set mytics 5
set terminal png size $opts{size3}
set output "$prefix-combined-reads.png"
plot "\$mean" using (0):(column(0)+1):(\$1 > 0.001 ? (\$1 < max_range ? \$1 : max_range ): 0.001):(0) with vector nohead lw $impw1 title "mean", \\
     "\$sd" using (0):(column(0)+1):(\$1 > 0.001 ? (\$1 < max_range ? \$1 : max_range ): 0.001):(0) with vector nohead lw $impw2 lt 3 title "s.d."
END
}
close($ch_reads);
system("gnuplot", "$prefix-combined-reads.gp") && die;

# combind-depth
if ($opts{orient} eq "h") {
    print $ch_depth <<"END";
set title "average depth per amplicon, all files"
set xlabel "amplicon"
set xrange [:$namp+1]
set ylabel "depth"
set logscale y
set key below
set title font "helvetica,20"
set xtics 5 font "helvetica,$xfont" scale -2,-1
set mxtics 5
set terminal png size $opts{size2}
set output "$prefix-combined-depth.png"
plot "\$mean" using (column(0)+1):(\$1 > 0.001 ? \$1 : 0.001) with impulses lw $impw1 title "mean", \\
     "\$sd" using (column(0)+1):(\$1 > 0.001 ? \$1 : 0.001) with impulses lw $impw2 lt 3 title "s.d."
END
} else {
    print $ch_depth <<"END";
# Compute max X value
stats \$mean nooutput
max_range = STATS_max
stats \$sd nooutput
max_range = max_range > STATS_max ? max_range : STATS_max
max_range = 10**ceil(log10(max_range+0.01))

set title "avg depth / amp, all files"
set ylabel "amplicon"
set yrange [0:$namp+1]
set xlabel "depth"
set xrange [0:max_range]
set grid; # xtics noytics
set logscale x
set format x "%.g"
set xtics font "helvectica,$yfont"
set key below
set title font "helvetica,20"
set ytics 5 font "helvetica,$xfont" scale -2,-1
set mytics 5
set terminal png size $opts{size3}
set output "$prefix-combined-depth.png"
plot "\$mean" using (0):(column(0)+1):(\$1 > 0.001 ? (\$1 < max_range ? \$1 : max_range) : 0.001):(0) with vector nohead lw $impw1 title "mean", \\
     "\$sd" using (0):(column(0)+1):(\$1 > 0.001 ? (\$1 < max_range ? \$1 : max_range) : 0.001):(0) with vector nohead lw $impw2 lt 3 title "s.d."
END
}
close($ch_depth);
system("gnuplot", "$prefix-combined-depth.gp") && die;

close($ch_rperc);
system("gnuplot", "$prefix-combined-read-perc.gp") && die;

close($ch_amp);
system("gnuplot", "$prefix-combined-amp.gp") && die;



#-----------------------------------------------------------------------------
# Also produce per file graphs
my $combined_done = 0;
foreach my $f (sort keys %file) {
    next if $f eq "COMBINED";
    my $ff = $f;
    $ff =~ s/[\/\\;#\$\{\}]/./g;  # safe filename component
    my $fg = $f;                  # printable in gnuplot
    $fg =~ s/_/\\\\_/g;

    #--- Template coordinates vs frequence: FILE
    goto skip_coord if !exists($file{$f}{FTCOORD});
    my $fn = "$prefix-$ff-tcoord";  # filename prefix
    open(my $fh, ">", "$fn.gp") || die "$fn.gp";

    print $fh <<"END";
set title "$fg: Template coordinate frequencies"
unset key
set xlabel "position"
set xrange [0:$ref_len]
set ylabel "frequency"
set yrange [*:*]
set logscale y
set mytics 10
set title font "helvetica,20"
set xtics out nomirror
set mxtics 5
set x2tics font "helvectica,6" offset 0,-0.6 scale -0.4 centre nomirror

set terminal png size $opts{size} truecolor
set output "$fn.png"
set linetype 1 lc "blue"
set linetype 2 lc "red"
set linetype 3 lc "black
seed=rand(-1)
END

    my @x2tics = ();
    for (my $i=1;$i<=$namp;$i++) {
        my $col = ($i%2)?"blue":"green";
        print $fh "set obj rect from $amp_start[$i], graph 0 to $amp_end[$i], graph 1 fillcolor rgb '$col' fillstyle transparent solid 0.1 noborder\n";
        if ($i%2 == 0) {
            my $ts = $i>=2    ? $amp_end[$i-1]   : $amp_start[$i];
            my $te = $i<$namp ? $amp_start[$i+1] : $amp_end[$i];
            my $tpos = ($ts+$te)/2;
            push(@x2tics, "\"$i\" " . ($amp_start[$i]+$amp_end[$i])/2);
        }
    }
    print $fh "set x2tics (" . join(", ", @x2tics) . ")\n";

    print $fh <<"END";
plot "-" using 1:(\$3+rand(0)):(\$2-\$1):(0):(int(\$4)?\$4+1:(int(\$5) % 2)) with vector nohead lw 3 lc var
END
    local $"="\n";
    print $fh "@{$file{$f}{FTCOORD}}\nend\n";

    close($fh);
    system("gnuplot", "$fn.gp") && die;

    #--- Template coordinates vs size: FILE
    my $fn = "$prefix-$ff-tsize";  # filename prefix
    open(my $fh, ">", "$fn.gp") || die "$fn.gp";

    print $fh <<"END";
set title "$fg: Template sizes"
unset key
set xlabel "position"
set xrange [0:$ref_len]
set ylabel "length"
set yrange [10:10000]
set logscale y
set mytics 10
set title font "helvetica,20"
set xtics out nomirror
set mxtics 5
set x2tics font "helvectica,6" offset 0,-0.6 scale -0.4 centre nomirror

set terminal png size $opts{size} truecolor
set output "$fn.png"
set linetype 1 lc "blue"
set linetype 2 lc "red"
set linetype 3 lc "black
seed=rand(-1)
END

    my @x2tics = ();
    for (my $i=1;$i<=$namp;$i++) {
        my $col = ($i%2)?"blue":"green";
        print $fh "set obj rect from $amp_start[$i], graph 0 to $amp_end[$i], graph 1 fillcolor rgb '$col' fillstyle transparent solid 0.1 noborder\n";
        if ($i%2 == 0) {
            my $ts = $i>=2    ? $amp_end[$i-1]   : $amp_start[$i];
            my $te = $i<$namp ? $amp_start[$i+1] : $amp_end[$i];
            my $tpos = ($ts+$te)/2;
            push(@x2tics, "\"$i\" " . ($amp_start[$i]+$amp_end[$i])/2);
        }
    }
    print $fh "set x2tics (" . join(", ", @x2tics) . ")\n";

    print $fh <<"END";
plot "-" using 1:(\$2-\$1+sqrt(\$3)*rand(0)):(\$2-\$1):(0):(int(log(sqrt(\$3)))) with vector nohead lw 2 lc var
END

    # Sort by descending freq so high freq colours are on top.
    local $"="\n";
    my @sorted = sort {
        [split(/\s+/,$a)]->[2] <=> [split(/\s+/,$b)]->[2]
    } split("\n", "@{$file{$f}{FTCOORD}}");
    print $fh "@sorted\nend\n";

    close($fh);
    system("gnuplot", "$fn.gp") && die;
  skip_coord:

    #--- Template coordinates: COMBINED
    if (scalar(@combined_coord) > 0 && !$combined_done) {
        my $fn = "$prefix-combined-tcoord";  # filename prefix
        open(my $fh, ">", "$fn.gp") || die "$fn.gp";

        print $fh <<"END";
set title "Template coordinate frequencies, all files"
unset key
set xlabel "position"
set xrange [0:$ref_len]
set ylabel "frequency"
set yrange [*:*]
set logscale y
set mytics 10
set title font "helvetica,20"
set xtics out nomirror
set mxtics 5
set x2tics font "helvectica,6" offset 0,-0.6 scale -0.4 centre nomirror

set terminal png size $opts{size} truecolor
set output "$fn.png"
set linetype 1 lc "blue"
set linetype 2 lc "red"
set linetype 3 lc "black
seed=rand(-1)
END

        my @x2tics = ();
        for (my $i=1;$i<=$namp;$i++) {
            my $col = ($i%2)?"blue":"green";
            print $fh "set obj rect from $amp_start[$i], graph 0 to $amp_end[$i], graph 1 fillcolor rgb '$col' fillstyle transparent solid 0.1 noborder\n";
            if ($i%2 == 0) {
                my $ts = $i>=2    ? $amp_end[$i-1]   : $amp_start[$i];
                my $te = $i<$namp ? $amp_start[$i+1] : $amp_end[$i];
                my $tpos = ($ts+$te)/2;
                push(@x2tics, "\"$i\" " . ($amp_start[$i]+$amp_end[$i])/2);
            }
        }
        print $fh "set x2tics (" . join(", ", @x2tics) . ")\n";

        print $fh <<"END";
plot "-" using 1:(\$3+rand(0)):(\$2-\$1):(0):(int(\$4)?\$4+1:(int(\$5) % 2)) with vector nohead lw 3 lc var
END
        local $"="\n";
        print $fh "@combined_coord\nend\n";

        close($fh);
        system("gnuplot", "$fn.gp") && die;
    }


    #--- Template depth: FILE
    my $fn = "$prefix-$ff-tdepth";  # filename prefix
    open(my $fh, ">", "$fn.gp") || die "$fn.gp";

    print $fh <<"END";
set title "$fg: Template depth per base"
set key below
set xlabel "position"
set xrange [0:$ref_len]
set ylabel "depth"
set yrange [1:$max_depth]
set logscale y
set mytics 10
set title font "helvetica,20"
set xtics out nomirror
set mxtics 5
set x2tics font "helvectica,6" offset 0,-0.6 scale -0.4 centre nomirror

set terminal png size $opts{size2} truecolor
set output "$fn.png"
set linetype 1 lc "blue"
set linetype 2 lc "#00B000"
xa=0
xv=0
END

    my @x2tics = ();
    for (my $i=1;$i<=$namp;$i++) {
        my $col = ($i%2)?"blue":"green";
        print $fh "set obj rect from $amp_start[$i], graph 0 to $amp_end[$i], graph 1 fillcolor rgb '$col' fillstyle transparent solid 0.1 noborder\n";
        if ($i%2 == 0) {
            my $ts = $i>=2    ? $amp_end[$i-1]   : $amp_start[$i];
            my $te = $i<$namp ? $amp_start[$i+1] : $amp_end[$i];
            my $tpos = ($ts+$te)/2;
            push(@x2tics, "\"$i\" " . ($amp_start[$i]+$amp_end[$i])/2);
        }
    }
    print $fh "set x2tics (" . join(", ", @x2tics) . ")\n";

    print $fh <<"END";
plot "-" using (xa=xa+\$2):(\$1+.1) with fsteps lw 1 title "all templates", \\
     "-" using (xv=xv+\$2):(\$1+.1) with fsteps lw 2 title "valid templates"
END
    if (exists($file{$f}{FDP_ALL})) {
        foreach (split(/\s+/,"@{$file{$f}{FDP_ALL}}")) {
            s/,/ /;
            print $fh "$_\n";
        }
    }
    print $fh "end\n";

    if (exists($file{$f}{FDP_VALID})) {
        foreach (split(/\s+/, "@{$file{$f}{FDP_VALID}}")) {
            s/,/ /;
            print $fh "$_\n";
        }
    }
    print $fh "end\n";

    close($fh);
    system("gnuplot", "$fn.gp") && die;


    #--- Template depth: FILE
    if (!$combined_done) {
        my $fn = "$prefix-combined-tdepth";  # filename prefix
        open(my $fh, ">", "$fn.gp") || die "$fn.gp";

        print $fh <<"END";
set title "Template depth per base, all files"
set key below
set xlabel "position"
set xrange [0:$ref_len]
set ylabel "depth"
set yrange [1:$max_depth]
set logscale y
set mytics 10
set title font "helvetica,20"
set xtics out nomirror
set mxtics 5
set x2tics font "helvectica,6" offset 0,-0.6 scale -0.4 centre nomirror

set terminal png size $opts{size2} truecolor
set output "$fn.png"
set linetype 1 lc "blue"
set linetype 2 lc "#00B000"
xa=0
xv=0
END

        my @x2tics = ();
        for (my $i=1;$i<=$namp;$i++) {
            my $col = ($i%2)?"blue":"green";
            print $fh "set obj rect from $amp_start[$i], graph 0 to $amp_end[$i], graph 1 fillcolor rgb '$col' fillstyle transparent solid 0.1 noborder\n";
            if ($i%2 == 0) {
                my $ts = $i>=2    ? $amp_end[$i-1]   : $amp_start[$i];
                my $te = $i<$namp ? $amp_start[$i+1] : $amp_end[$i];
                my $tpos = ($ts+$te)/2;
                push(@x2tics, "\"$i\" " . ($amp_start[$i]+$amp_end[$i])/2);
            }
        }
        print $fh "set x2tics (" . join(", ", @x2tics) . ")\n";

        print $fh <<"END";
plot "-" using (xa=xa+\$2):((\$1+.1)/$nfile) with fsteps lw 1 title "all templates", \\
     "-" using (xv=xv+\$2):((\$1+.1)/$nfile) with fsteps lw 2 title "valid templates"
END
        if (exists($file{COMBINED}{CDP_ALL})) {
            foreach (split(/\s+/,"@{$file{COMBINED}{CDP_ALL}}")) {
                s/,/ /;
                print $fh "$_\n";
            }
        }
        print $fh "end\n";

        if (exists($file{COMBINED}{CDP_VALID})) {
            foreach (split(/\s+/, "@{$file{COMBINED}{CDP_VALID}}")) {
                s/,/ /;
                print $fh "$_\n";
            }
        }
        print $fh "end\n";

        close($fh);
        system("gnuplot", "$fn.gp") && die;
    }

    #--- Read count / depth
    my $fn = "$prefix-$ff-reads";  # filename prefix
    open(my $fh, ">", "$fn.gp") || die "$fn.gp";

    if ($opts{orient} eq "h") {
        print $fh <<"END";
set title "$fg: read count per amplicon
set key below
set xlabel "amplicon"
set xrange [0:$namp+1]
set ylabel "no. reads"
set logscale y
set yrange [1:$max_depth]
set title font "helvetica,20"
set xtics 5 font "helvectica,$xfont" scale -2,-1
set mxtics 5
set terminal png size $opts{size2}
set output "$fn.png"
plot "-" using (column(0)+1):(\$1 > 0.001 ? \$1 : 0.001) with impulses lw $impw1 title "#reads", \\
     "-" using (column(0)+1):(\$1 > 0.001 ? \$1 : 0.001) with impulses lw $impw2 lt 5 title "all depth",\\
     "-" using (column(0)+1):(\$1 > 0.001 ? \$1 : 0.001) with impulses lw $impw2 lt 3 title "usable depth",
END
    } else {
        print $fh <<"END";
set title "$fg:\\nread count per amplicon
set key below
set ylabel "amplicon"
set yrange [0:$namp+1]
set xlabel "no. reads"
set xrange [1:$max_depth]
set grid; # xtics noytics
set logscale x
set xtics font "helvectica,$yfont"
set title font "helvetica,20"
set ytics 5 font "helvectica,$xfont" scale -2,-1
set mytics 5
set terminal png size $opts{size3}
set output "$fn.png"
plot "-" using (0):(column(0)+1):(\$1 > 0.001 ? (\$1 < $max_depth ? \$1 : $max_depth) : 0.001):(0) with vector nohead lw $impw1 title "#reads", \\
     "-" using (0):(column(0)+1):(\$1 > 0.001 ? (\$1 < $max_depth ? \$1 : $max_depth) : 0.001):(0) with vector nohead lw $impw2 lt 5 title "all depth",\\
     "-" using (0):(column(0)+1):(\$1 > 0.001 ? (\$1 < $max_depth ? \$1 : $max_depth) : 0.001):(0) with vector nohead lw $impw2 lt 3 title "usable depth",
END
    }

    local $"="\n";
    print $fh "@{$file{$f}{FREADS}}[2..$#{$file{$f}{FREADS}}]\nend\n";
    print $fh "@{$file{$f}{FDEPTH}}[2..$#{$file{$f}{FDEPTH}}]\nend\n";
    print $fh "@{$file{$f}{FVDEPTH}}[2..$#{$file{$f}{FVDEPTH}}]\nend\n";

    close($fh);
    system("gnuplot", "$fn.gp") && die;

    #--- Read %coverage and %read-per-amplicon
    my $fn = "$prefix-$ff-cov";  # filename prefix
    open(my $fh, ">", "$fn.gp") || die "$fn.gp";

    if ($opts{orient} eq "h") {
        print $fh <<"END";
set title "$fg: percentage coverage to specific depth(s)"
set key below
set xlabel "amplicon"
set xrange [0:$namp+1]
set ylabel "%coverage"
set yrange [0:100]
set title font "helvetica,20"
set xtics 5 font "helvectica,$xfont" scale -2,-1
set mxtics 5
set ytics nomirror
set y2tics

set terminal png size $opts{size2}
set output "$fn.png"
plot \\
END
    } else {
        print $fh <<"END";
set title "$fg: % coverage at depth(s)"
set key below
set ylabel "amplicon"
set yrange [$namp+1:0]
#set xlabel "%coverage"
set xrange [0:100]
set title font "helvetica,14"
set ytics 5 font "helvectica,$xfont" scale -2,-1
set mytics 5
set xtics 10 font "helvetica,12"
set mxtics 5
set x2tics 10 font "helvetica,12"

set terminal png size $opts{size3}
set output "$fn.png"
plot \\
END
    }
    #my $lw = 5;
    my $lw = ($namp >= 100) ? 3 : 2;
    my @lt = ("rgb \"#900020\"","rgb \"#2060FF\"",2,3,4,5,6,7,8,9);
    my $lt = 0;
    foreach (sort {
                 my $x=$a; $x=~s/FPCOV-(\d+)/\1/;
                 my $y=$b; $y=~s/FPCOV-(\d+)/\1/;
                 $x <=> $y
             } keys %{$file{$f}}) {
        next unless /^FPCOV-(\d+)/;
        if ($opts{orient} eq "h") {
            print $fh "\"-\" using (column(0)+1):1 with impulses lw $lw lt $lt[$lt] title \"\depth >= $1\", \\\n";
            $lw += ($namp >= 100) ? ($lw<4) : ($lw<5)*2;
            #print $fh "\"-\" using (column(0)+1):1 with linespoints lw $lw lt $lt[$lt] title \"\%coverage >= $1\", \\\n";
            #$lw -= ($lw>1)*2;
        } else {
            print $fh "\"-\" using (0):(column(0)+1):1:(0) with vector nohead lw $lw lt $lt[$lt] title \"depth>=$1\", \\\n";
            $lw += ($lw<5)*2;
        }
        $lt++;
    }
    print $fh "\n";
    #print $fh "\"-\" with linespoints lw 3 lt 3 title \"\%reads/amp\" axis x1y2\n";

#plot "-" with linespoints lw 3 title "%coverage", \\
#     "-" with linespoints lw 3 lt 3 title "%reads/amp" axis x1y2
#END

    local $"="\n";
    foreach (sort {
                 my $x=$a; $x=~s/FPCOV-(\d+)/\1/;
                 my $y=$b; $y=~s/FPCOV-(\d+)/\1/;
                 $x <=> $y
             } keys %{$file{$f}}) {
        next unless /^FPCOV-(\d+)/;
        print $fh "@{$file{$f}{$_}}[2..$#{$file{$f}{$_}}]\nend\n";
    }
    #print $fh "@{$file{$f}{FRPERC}}[2..$#{$file{$f}{FRPERC}}]\nend\n";

    close($fh);
    system("gnuplot", "$fn.gp") && die;


    #--- Amplicon primer correctness
    my $fn = "$prefix-$ff-amp";  # filename prefix
    open(my $fh, ">", "$fn.gp") || die "$fn.gp";

    if ($opts{orient} eq "h") {
        print $fh <<"END";
set title "$fg: Percentage of read-pairs with incorrectly positioned primers"
unset key
set xlabel "amplicon"
set xrange [0:$namp+1]
set ylabel "%incorrect"
set yrange [0:100]
set title font "helvetica,20"
set xtics 5 font "helvectica,$xfont" scale -2,-1
set mxtics 5

set terminal png size $opts{size2}
set output "$fn.png"
plot "-" using (column(0)+1):1 with impulses lw $impw1
END
    } else {
        print $fh <<"END";
set title "$fg:\\n% mis-priming read-pairs"
unset key
set grid
set ylabel "amplicon"
set yrange [0:$namp+1]
set xlabel "%incorrect"
set xrange [0:100]
set title font "helvetica,20"
set ytics 5 font "helvectica,$xfont" scale -2,-1
set mytics 5
set terminal png size $opts{size3}
set output "$fn.png"
plot "-" using (0):(column(0)+1):1:(0) with vector nohead lw $impw1
END
    }
    local $"="\n";
    print $fh "@{$file{$f}{FAMP}}[1..$#{$file{$f}{FAMP}}]\nend\n";

    close($fh);
    system("gnuplot", "$fn.gp") && die;

    $combined_done = 1;
}

#---------------------------------
#adding html file to show plots
index_only:

# index.html is in the same dir as the images
my ($prefix_dir) = $prefix=~/(.*\/)/;
my $fname  = "${prefix_dir}index.html";

open(my $fh,'>',$fname) or error("$fname: $!");
print $fh q[
<html>
<head>
<style>
.thumbnail
{
    text-decoration:none;
    color:black;
    font-weight:bold;
}
.imgs td
{
    vertical-align:middle;
    padding: 0.5em;
    border: 1px solid black;
}
table.imgs
{
    border-collapse:collapse;
    margin-left:20px;
}
</style>
</head>
<body>
<table class="imgs">
];

my @imgs = sort {
    my ($A,$B)=($a,$b);
    $A=~s/(\d+)/sprintf("%09d",$1)/ge;
    $B=~s/(\d+)/sprintf("%09d",$1)/ge;
    $A cmp $B
} grep {!/thumb\.png/} <"$prefix*.png">;

my $last = "";
my $new_section = 0;
for (my ($i,$j)=(0,0); $i < @imgs; $i++, $j++)
{
    my $fn_base = $imgs[$i];
    $fn_base =~ s/-(\w+|read-perc|read-perc-log)(-\d+)*\.png$//;
    if ($fn_base ne $last || $j % 6 == 0) {
        if ($fn_base ne $last) {
            $last=$fn_base;
            $new_section = 1;
            $j = 0;
        }
    
        if ( $i>0 ) { print $fh "</tr>\n"; }
        if ($new_section) {
            print $fh "<tr><td>$fn_base</td></tr>\n";
            $new_section = 0;
        }
        print $fh "<tr>";
    }
    my ($img) = $imgs[$i]=~/(?:.*\/)?(.*)/;
    if ($opts{thumbnails}) {
        my $scale = 100*$opts{thumb_size}/[split(",",$opts{size})]->[0],"\n";
        system("convert", "-scale", "$scale%", $imgs[$i], "$imgs[$i].thumb.png") && die;
        print $fh qq[<td><a class="thumbnail" href="$img"><img src="$img.thumb.png" width="$opts{thumb_size}px"></a></td>\n];
    } else {
        print $fh qq[<td><a class="thumbnail" href="$img"><img src="$img" width="$opts{thumb_size}px"></a></td>\n];
    }
}
print $fh qq[
</tr>
</table>
</body>
</html>
];

close($fh);