go(de): implement Init(),Reinit() on Population

algo/de/population.go

@@ -3,6 +3,12 @@
 
 package de
 
+import (
+	"golang.org/x/exp/rand"
+
+	"gonum.org/v1/gonum/stat/distuv"
+)
+
 type (
 	// DecisionVector is a []float64 abstraction representing the decision vector.
 	DecisionVector []float64
@@ -51,11 +57,24 @@ func (p *Population) GetWorstIdx() int                           { return 0 }
 func (p *Population) SetX(n int, nuX DecisionVector)             {}
 func (p *Population) SetV(n int, nuV DecisionVector)             {}
 
-// Init initialises all individuals.
-func (p *Population) Init() {}
+// Init initialises all individuals to random values.
+func (p *Population) Init() {
+	uniform := distuv.Uniform{}
+	uniform.Src = rand.NewSource(p.Seed)
+
+	for _, v := range p.Population {
+		v.CurX = make([]float64, p.Dimen)
+
+		for i := 0; i < p.Dimen; i++ {
+			v.CurX[i] = uniform.Rand()
+		}
+	}
+}
 
 // Reinit reinitialises all individuals.
-func (p *Population) Reinit() {}
+func (p *Population) Reinit() {
+	p.Init()
+}
 
 // ReinitN reinitialises the individual at position n.
 func (p *Population) ReinitN(n uint) {}