my @deltas = map{ ( 0 <=> $y[$_-1] - $y[$_] ) } 1 .. $#y;

##</code><code>##

-1 1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 1 1 1 1 1 1 1 1 -1 -1 -1 -1 1 1 1 1 1 1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 1 1 1 1 1 1 1

##</code><code>##

$deltas[$_-1] != $deltas[$_] and $im->line( $x[$_], 0, $x[$_], 800, 0 ) for 1 .. $#x-1;

##</code><code>##

#! perl -slw
use strict;
use Data::Dump qw[ pp ];
use GD;
use constant {
    WHITE => unpack( 'N', pack 'CCCC', 0, 255, 255, 255 ),
    RED   => unpack( 'N', pack 'CCCC', 0, 255,   0,   0 ),
    GREEN => unpack( 'N', pack 'CCCC', 0,   0, 255,   0 ),
    BLUE  => unpack( 'N', pack 'CCCC', 0,   0,   0, 255 ),
};

my( @x, @y, @yd1, @yd2 );
( $x[@x], $y[@y], $yd1[@yd1], $yd2[@yd2] ) = map{ $_ //= 0 } split while <DATA>;
chomp @yd2;

$_ = ( $_ -4 ) * 1000 for @x;
$_ /= 6   for @y;
$_ = $_ / 320 + 400 for @yd1;
$_ = $_ / 8000 + 400 for @yd2;


my $im = GD::Image->new( 1000, 800, 1 );
$im->filledRectangle( 0, 0, 1000, 800, WHITE );
$im->line( 0, 400, 1000, 400, 0 );
$im->line( $x[$_-1], $y[$_-1], $x[$_], $y[$_], RED ) for 1 .. $#x;
$im->line( $x[$_-1], $yd1[$_-1], $x[$_], $yd1[$_], GREEN ) for 2 .. $#x-1;
$im->line( $x[$_-1], $yd2[$_-1], $x[$_], $yd2[$_], BLUE ) for 3 .. $#x-2;

my @deltas = map{ ( 0 <=> $y[$_-1] - $y[$_] ) } 1 .. $#y;
$deltas[$_-1] != $deltas[$_] and $im->line( $x[$_], 0, $x[$_], 800, 0 ) for 1 .. $#x-1;

$im->flipVertical;

open PNG, '>:raw', "$0.png" or die $!;
print PNG $im->png;
close PNG;

system 1, "$0.png";

##</code><code>##

__DATA__
4.1330 4580.87
4.1470 4522.75     -1328.56
4.1600 4545.00     -7791.65     -935707.98
4.1730 4320.17    -25656.96    -1544908.57
4.1870 3852.26    -49504.19    -1396364.62
4.2000 2983.56    -63358.81       59518.52
4.2130 2204.93     -47956.7     1368481.22
4.2270 1688.73    -26409.81     1302338.03
4.2400 1491.87    -12793.58      687964.39
4.2530 1356.09     -8522.74      246232.62
4.2670 1261.75      -6145.3       120543.1
4.2800 1190.17     -5268.08       99532.76
4.2930 1124.78     -3557.44      180758.68
4.3070 1094.12      -387.59      357928.14
4.3200 1114.32      6106.62      533914.53
4.3330 1252.89     13494.19      473482.01
4.3470 1478.66     18890.63      334228.18
4.3600 1762.94     22518.35       61078.35
4.3730 2064.14     20478.67     -278669.88
4.3870 2315.86     14994.26     -533957.74
4.4000 2468.98      6061.81     -715688.03
4.4130 2473.47     -3613.63     -574250.77
4.4270 2371.42     -9442.96     -274812.86
4.4400 2218.51    -11033.58       93502.85
4.4530 2084.54     -7011.89      376399.97
4.4670 2029.19      -870.78       468240.9
4.4800 2061.03      5630.62      455004.27
4.4930 2175.58     10959.33      278503.96
4.5070 2356.93     13150.22       13708.45
4.5200 2530.64     11329.46      -316569.8
4.5330 2651.50      4919.41     -526292.81
4.5470 2663.46     -2880.44     -563985.17
4.5600 2573.73    -10308.19     -476770.66
4.5730 2395.45    -15276.48     -346338.56
4.5870 2161.26    -19659.33      -286611.8
4.6000 1864.65       -23015      -18659.54
4.6130 1562.87    -20144.48      218052.13
4.6270 1320.75    -17127.59      195150.31
4.6400 1100.43    -14875.42      287534.19
4.6530  933.99      -9651.7      387333.91
4.6670  839.83     -4417.41      369091.59
4.6800  814.72       313.77      341683.76
4.6930  847.99      4466.37      298057.93
4.7070  935.31      8361.33      382671.47
4.7200 1073.75      14798.5      519444.44
4.7330 1320.07     21866.89      519764.75
4.7470 1664.15     28832.15      506969.93
4.7600 2098.54     35555.08
4.7730 2588.58