Data commit

Task/Random-numbers/Avail/random-numbers.avail

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+Method "U(_,_)" is
+[
+	lower : number,
+	upper : number
+|
+	divisor ::= ((1<<32)) ÷ (upper - lower)→double;
+	map a pRNG through [i : integer | (i ÷ divisor) + lower]
+];
+
+Method "a Marsaglia polar sampler" is
+[
+	generator for
+		[
+			yield : [double]→⊤
+		|
+			source ::= U(-1, 1);
+			Repeat [
+				x ::= take 1 from source[1];
+				y ::= take 1 from source[1];
+				s ::= x^2 + y^2;
+				If 0 < s < 1 then
+				[
+					factor ::= ((-2 × ln s) ÷ s) ^ 0.5;
+					yield(x × factor);
+					yield(y × factor);
+				];
+			]
+		]
+];
+
+// the default distribution has mean 0 and std dev 1.0, so we scale the values
+sampler ::= map a Marsaglia polar sampler through [d : double | d ÷ 2.0 + 1.0];
+values ::= take 1000 from sampler;