Data commit

Task/Superellipse/Jq/superellipse.jq

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+# Input: [x, y]
+def mult($a; $b): [.[0]*$a, .[1]*$b] ;
+
+# Input: a number
+def round($n): . * $n | floor / $n;
+
+# svg header boilerplate
+def svg($h; $w):
+  "<?xml version='1.0' standalone='no'?>",
+  "<!DOCTYPE svg PUBLIC '-//W3C//DTD SVG 1.1//EN' 'http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd'>",
+  "<svg height='\($h)' width='\($w)' version='1.1' xmlns='http://www.w3.org/2000/svg'>";
+</syntaxhighlight<68>>
+'''Superellipse functions'''
+<syntaxhighlight lang=jq>
+# y in terms of x
+# input: {a,b,n}
+def y($x): (.b *  pow( (1 - pow( ($x/.a)|length ; .n) ) ; 1/.n )) | round(10);
+
+# input: {a,b,n}
+def pline(q):
+  "<polyline points='\(q|map(join(","))|join(" "))'",
+  " style='fill:none; stroke:black; stroke-width:3' transform='translate(\(.a + 10), \(.b + 10))' />";
+
+# input: {a,b,n}
+def plot:
+  # points for one quadrant
+  [range(0;400) as $i | [$i, y($i)] | select(.[1] | isnan | not) ] as $q
+  |
+    pline($q),
+    pline($q | map( mult(1;-1))),  # flip and mirror
+    pline($q | map( mult(-1;-1))), # for the other
+    pline($q | map( mult(-1;1)))   # three quadrants
+;
+
+# Input: {a,b,n} - the constants for the superellipse
+def superellipse:
+  svg(.b*2 + 10; .a*2 + 10), plot, "</svg>";
+
+{ a: 200,  b: 200,  n: 2.5 }
+| superellipse