cdf tweak

microgopt.go

@@ -411,9 +411,9 @@ func choose(p []*value) int {
 	// Generation:
 	// 1. Generate a uniformly-random value x in the range [0,1)
 	// 2. Using a binary search, find the index of the smallest element in cdf larger than x
-	var val float64
+
 	// multiply the sample with the largest CDF value; easier than normalizing to [0,1)
-	val = rand.Float64() * cdf[len(cdf)-1]
+	val := rand.Float64() * cdf[len(cdf)-1]
 	// Search returns the smallest index i such that cdf[i] > val
 	return sort.Search(len(cdf), func(i int) bool { return cdf[i] > val })
 }