A star pattern in SVG

<svg height="800" width="800" xmlns="http://www.w3.org/2000/svg">
<defs>
<g transform="scale(0.33,0.33)" id='star'>
<polygon points='22.45 -30.9 95.11 -30.9 36.33 11.8 58.78 80.9 0 38.2
-58.78 80.9 -36.33 11.8 -95.11 -30.9 -22.45 -30.9 0 -100'/>
</g>
<g id='rwb'>
<g transform='translate(0 -300)'>
<use href='#star' fill='red'/>
</g>
<g transform='rotate(15) translate(0 -300)'>
<use href='#star' fill='blue'/>
</g>
<g transform='rotate(30) translate(0 -300)'>
<use href='#star' fill='none' stroke='black' stroke-width='2.5'/>
</g>
</g>
<g id='quarter'><use href='#rwb'/>
<g transform='rotate(45)'><use href='#rwb'/></g>
</g>
<g id='half'><use href='#quarter'/>
<g transform='rotate(90)'><use href='#quarter'/></g>
</g>
<g id='circle'><use href='#half'/>
<g transform='rotate(180)'><use href='#half'/></g>
</g>
</defs>
<g transform='translate(400 400)'>
<use href='#circle'/>
<g transform='rotate(5) scale(0.75)'>
<use href='#circle'/>
</g>
<g transform='rotate(10) scale(0.56)'>
<use href='#circle'/>
</g>
<g transform='rotate(15) scale(0.42)'>
<use href='#circle'/>
</g>
<g transform='rotate(15) scale(0.316)'>
<use href='#circle'/>
</g>
</g>
</svg>

(download)

#!/home/ben/software/install/bin/perl
use Z;
use Math::Trig;

my $twof = 4*pi/5;
my $s144 = sin ($twof);
my $c144 = cos ($twof);
my $t144 = $s144 / ($c144 - 1);
my $x = (cos (2*pi/5) - 1) * $t144;
my $y = 1 + $x / $t144;
my $exy = cos (deg2rad (72));
my $factor = sqrt ($x**2 + $y**2);
my $radius = 100;
my $max = 10;
my @points;
for my $s (1..$max) {
    my $a = 2*pi*$s/$max;
    my $r = $radius;
    if (($s % 2) == 1) {
        $r *= $factor;
    }
    my $x = sin ($a) * $r;
    my $y = -cos ($a) * $r;
    push @points, [$x, $y];
}
print <<EOF;
<svg height="800" width="800" xmlns="http://www.w3.org/2000/svg">
EOF
print "<polygon points='";
for my $point (@points) {
    printf ("%.2f %.2f\n", $point->[0], $point->[1]);
}
print "'/>\n";
print <<EOF;
</svg>
EOF

(download)