t3du - Probabilistic Index Node

leenkx/Sources/leenkx/logicnode/ProbabilisticIndexNode.hx

@@ -0,0 +1,41 @@
+package leenkx.logicnode;
+
+class ProbabilisticIndexNode extends LogicNode {
+
+	public function new(tree: LogicTree) {
+		super(tree);
+	}
+
+	override function get(from: Int): Dynamic {
+
+		var probs: Array<Float> = [];
+		var probs_acum: Array<Float> = [];
+		var sum: Float = 0;
+
+		for (p in 0...inputs.length){
+			probs.push(inputs[p].get());
+			sum += probs[p];
+		}
+
+		if (sum > 1){
+			for (p in 0...probs.length)
+				probs[p] /= sum;
+		}
+
+		sum = 0;
+		for (p in 0...probs.length){
+			sum += probs[p];
+			probs_acum.push(sum);
+		}
+
+		var rand: Float = Math.random();
+
+		for (p in 0...probs.length){
+			if (p == 0 && rand <= probs_acum[p]) return p;
+			else if (0 < p && p < probs.length-1 && probs_acum[p-1] < rand && rand <= probs_acum[p]) return p;
+			else if (p == probs.length-1 && probs_acum[p-1] < rand) return p;
+		}
+
+		return null;
+	}
+}