> For the complete documentation index, see [llms.txt](https://trizen.gitbook.io/perl6-rosettacode/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://trizen.gitbook.io/perl6-rosettacode/programming_tasks/s/superellipse.md).

# Superellipse

```perl
my (\a, \b, \n) = 200, 200, 2.5;

# y in terms of x
sub y ($x) { floor b × (1 - ($x/a).abs ** n ) ** (1/n) }

# find point pairs for one quadrant
my @q = flat map -> \x { x, y(x) }, ^(a+1);

my $out = open('superellipse.svg', :w);
$out.print: [~] qq|<svg height="{b×2}" width="{a×2}" xmlns="https://www.w3.org/2000/svg">\n|,
  pline( @q ),
  pline( @q «×» < 1 -1> ), # flip and mirror
  pline( @q «×» <-1 -1> ), # for the other
  pline( @q «×» <-1  1> ), # three quadrants
  '</svg>';

sub pline (@q) {
  qq|<polyline points="{@q}"
  style="fill:none;stroke:black;stroke-width:3"
  transform="translate({a}, {b})" />\n|
}
```

[Superellipse](https://github.com/SqrtNegInf/Rosettacode-Perl6-Smoke/blob/master/ref/superellipse.svg) (offsite image)