#!/usr/bin/perl
use strict;
use warnings;

my @points;
for (1 .. 100) {
    my $x = rand()**2;
    my $y = function($x);
    my $dy = 0.01 + $x*0.1*rand()**2;
    $y += offset($dy);
    push @points, [map sprintf("%.4f", $_), $x, $y, $dy];
}

$, = "\n";
$" = "\t";
print map("@$_", @points), "\n";


sub function {
    my ($x) = @_;
    return 0.25 + 0.75*(1-$x)**0.25;
}

sub offset {
    my ($x) = @_;
    return $x*(rand()-0.5)*exp(rand());
}

##</code><code>##

#!/usr/bin/perl
use strict;
use warnings;

my @points;
push @points, [split] while <DATA>;
$_ = {x => $_->[0], 'y' => $_->[1], dy => $_->[2]} for @points;

for my $point (@points) {
    $point->{value} = $point->{y}/$point->{dy}; # Low relative uncertainty is good
    $point->{dist} += ($_->{x} - $point->{x})**2 for @points; # Isolated points are good
}

while (@points > 50) {
    my $low_score = score($points[0]);
    my $low_index = 0;
    for my $i (0 .. $#points) {
        if (score($points[$i]) < $low_score) {
            $low_score = score($points[$i]);
            $low_index = $i;
        }
    }
    my $low_point = splice @points, $low_index, 1;
    $_->{dist} -= ($_->{x} - $low_point->{x})**2 for @points; 
}

for my $point (@points) {
    print join "\t", $point->{x}, $point->{y}, $point->{dy}, "\n";
}


sub score {
    my ($point) = @_;
    return $point->{value} + 1000*$point->{dist};
}

__DATA__
0.3137	0.9230	0.0213
0.0353	0.9927	0.0028
0.5431	0.8256	0.0893
0.4871	0.8657	0.0098
0.5935	0.8637	0.0645
0.5340	0.7873	0.0932
0.1667	0.9532	0.0062
0.0241	0.9978	0.0070
0.1068	0.9785	0.0142
0.3129	0.9014	0.0286
0.3319	0.9078	0.0028
0.0006	0.9791	0.0429
0.1436	0.9697	0.0285
0.0925	0.9746	0.0053
0.1347	0.9641	0.0024
0.4304	0.8877	0.0364
0.1306	0.9987	0.0502
0.4056	0.8653	0.0634
0.0539	1.0031	0.0352
0.0468	0.9217	0.0943
0.0397	0.9802	0.0503
0.1994	0.9252	0.0486
0.0345	0.9916	0.0013
0.5689	0.8306	0.0040
0.2189	1.0476	0.0927
0.4173	0.8850	0.0149
0.8645	0.6728	0.0556
0.0586	0.9900	0.0819
0.4643	0.7884	0.0659
0.3554	0.9173	0.0410
0.4400	0.9074	0.0831
0.0382	1.0116	0.0461
0.0188	0.9934	0.0069
0.1505	0.9898	0.0540
0.3959	0.8792	0.0195
0.5443	0.8225	0.0148
0.9776	0.5572	0.0651
0.2192	0.9609	0.0370
0.4869	0.8621	0.0211
0.0499	0.9876	0.0011
0.2295	0.9325	0.0204
0.1222	0.9540	0.0418
0.2911	0.9215	0.0015
0.6095	0.8270	0.0235
0.2518	0.8968	0.0456
0.1540	0.9798	0.0529
0.0344	1.0038	0.0227
0.1534	0.9149	0.0608
0.8540	0.6901	0.0060
0.8015	0.7142	0.0249
0.0008	1.0756	0.0734
0.1346	0.9768	0.0183
0.1167	0.9697	0.0013
0.9690	0.5879	0.0023
0.3193	0.9115	0.0036
0.1110	1.0015	0.0546
0.0373	1.0053	0.0231
0.0016	0.9734	0.0946
0.1820	0.9648	0.0209
0.0091	0.9976	0.0013
0.1699	0.9791	0.0343
0.4183	0.8819	0.0010
0.2560	0.9270	0.0091
0.9714	0.5897	0.0251
0.0014	0.9733	0.0304
0.0940	0.9597	0.0524
0.0501	0.9869	0.0530
0.3157	0.9057	0.0220
0.2149	0.9412	0.0047
0.1635	0.9578	0.0011
0.0581	1.0069	0.0311
0.5995	0.8179	0.0056
0.0625	0.9535	0.0919
0.0262	1.0081	0.0191
0.0267	1.0211	0.0902
0.9126	0.6475	0.0020
0.4535	0.8672	0.0085
0.3254	0.9136	0.0065
0.0019	0.9989	0.0592
0.0639	0.9791	0.0083
0.1951	0.9082	0.0838
0.2899	0.9061	0.0741
0.5317	0.8421	0.0010
0.1340	0.9659	0.0012
0.0617	0.9754	0.0609
0.5550	0.8363	0.0087
0.1242	0.9704	0.0071
0.4895	0.8538	0.0040
0.0087	0.9990	0.0064
0.8741	0.6770	0.0111
0.2771	0.9227	0.0024
0.0887	0.9354	0.0545
0.2974	0.9186	0.0010
0.4166	0.8802	0.0093
0.0010	1.0137	0.0992
0.0298	0.9960	0.0119
0.1383	0.9629	0.0034
0.3617	0.8983	0.0018
0.0035	0.9874	0.0340
0.7896	0.7058	0.0764