Add convenience functions for the "default" normal distribution and bidders distributed thereby.

auctionsim/defaults.go

@@ -0,0 +1,31 @@
+package auctionsim
+
+import (
+	"math/rand"
+)
+
+/**
+ * NormalestDistribution returns a NormalDistribution with a new rand.Rand
+ * behind it (randomly seeded), with standard deviation of 1 and mean of 0.
+ */
+func NormalestDistribution() *NormalDistribution {
+	return &NormalDistribution{
+		Rand: rand.New(rand.NewSource(int64(rand.Uint64()))),
+		StdDev: 1,
+		Mean: 0,
+	}
+}
+
+/**
+ * NormalestBidderGenerator returns a BidderGenerator that returns an infinite
+ * number of Bidders with infinite cash, and values and errors normally
+ * distributed around 0.
+ */
+func NormalestBidderGenerator() BidderGenerator {
+	d := NormalestDistribution()
+	return &BiddersFromDistributions{
+		Values: d,
+		Irrationalities: d,
+		Bankrolls: ConstDistribution(math.Inf(1)),
+	}
+}

auctionsim/generators.go

@@ -79,7 +79,6 @@ func (n *NormalDistribution) Draw() (float64, bool) {
 	return n.Rand.NormFloat64() * n.StdDev + n.Mean, true
 }
 
-
 /**
  * ConstDistribution is a Distribution that always returns the same value.
  */