#!/usr/bin/perl -w

use 5.030;

my @data;
if (@ARGV){
    @data = @ARGV;
}else{
    @data = split /\s+/, <>;
}

die "Error: Not tput utility" if (length(`which tput`)<3);   
my $lines = `tput lines`;
chomp $lines;
$lines--;
my $cols = `tput cols`;
chomp $cols;
$cols--;

if (@data < 3 || @data > $cols){
    say "USAGE:";
    say "";
    say "$0 <data1 data2 ... data$cols>";
    say "for printing a simple min-max plot $lines x $cols";
    die "TOO FEW POINTS" if @data < 3;
    warn "TOO MUCH POINTS" if @data > $cols;
}

my $max = -9e99;
my $min = 9e99;
my $counter = 0;
for my $i (@data){
    $counter++;
    if (0+$i ne $i) { die "Not numeric $i at point $counter"; }
    if ($i <= $min) { $min = $i; }
    if ($i >= $max) { $max = $i; }
    last if $counter == $cols;
}
die "Error: nothing to plot! (min==max)." if $min == $max;
my $range = $lines/($max-$min);

my @xy;
for my $y (1..$lines){                     # MIN-MAX AXIS
    $xy[$y][1] = "|";
    $xy[$y][$cols+1] = "\n";  
    if ($y == $lines){
	$xy[$y][1] = "+";
	for (2..$cols) { $xy[$y][$_] = "-"; }
    }
}

my %h;
for my $x (1..$counter){
    $h{ $data[$x-1] } = 1+ int ( ( $max-$data[$x-1] ) * $range );
    $xy[ $h{ $data[$x-1] } ][$x] = "0";
}

for my $y (1..$lines){
    for my $x (1..$cols+1){
	if (defined $xy[$y][$x]){
	    print $xy[$y][$x];
	}else{
	    if ( $y % 20 == 0 && $x % 40 == 0 ){
		print "·";
	    }else{
		print " ";
	    }
	}
    }
}

exit 0;

__END__

Simple min-max plot in xterm