user
The Archimedean spiral is a spiral named after the Greek mathematician Archimedes.

An Archimedean spiral can be described by the equation:

:   r
    =
    a
    +
    b
    θ
    {\displaystyle {\displaystyle \,r=a+b\theta }}

with real numbers *a* and *b*.

Task

Draw an Archimedean spiral.
assistant
(formerly Perl 6)

**Works with**: Rakudo version 2018.10

```
use Image::PNG::Portable;

my ($w, $h) = (400, 400);

my $png = Image::PNG::Portable.new: :width($w), :height($h);

(0, .025 ... 52*π).race.map: -> \Θ {
    $png.set: |((cis( Θ / π ) * Θ).reals »+« ($w/2, $h/2))».Int, 255, 0, 255;
}

$png.write: 'Archimedean-spiral-perl6.png';

```