Example #1
0
// EvolveOneGroup evolves one group (CPU)
func (o *Optimiser) EvolveOneGroup(cpu int) (nfeval int) {

	// auxiliary
	G := o.Groups[cpu].All // competitors (old and new)
	I := o.Groups[cpu].Indices
	P := o.Groups[cpu].Pairs

	// compute random pairs
	rnd.IntGetGroups(P, I)
	np := len(P)

	// create new solutions
	z := o.Groups[cpu].Ncur // index of first new solution
	for k := 0; k < np; k++ {
		l := (k + 1) % np
		m := (k + 2) % np
		n := (k + 3) % np

		A := G[P[k][0]]
		A0 := G[P[l][0]]
		A1 := G[P[m][0]]
		A2 := G[P[n][0]]

		B := G[P[k][1]]
		B0 := G[P[l][1]]
		B1 := G[P[m][1]]
		B2 := G[P[n][1]]

		a := G[z+P[k][0]]
		b := G[z+P[k][1]]

		if o.Nflt > 0 {
			DiffEvol(a.Flt, A.Flt, A0.Flt, A1.Flt, A2.Flt, &o.Parameters)
			DiffEvol(b.Flt, B.Flt, B0.Flt, B1.Flt, B2.Flt, &o.Parameters)
		}

		if o.Nint > 0 {
			o.CxInt(a.Int, b.Int, A.Int, B.Int, &o.Parameters)
			o.MtInt(a.Int, &o.Parameters)
			o.MtInt(b.Int, &o.Parameters)
		}

		if o.BinInt > 0 && o.ClearFlt {
			for i := 0; i < o.Nint; i++ {
				if a.Int[i] == 0 {
					a.Flt[i] = 0
				}
				if b.Int[i] == 0 {
					b.Flt[i] = 0
				}
			}
		}

		o.ObjFunc(a, cpu)
		o.ObjFunc(b, cpu)
		nfeval += 2
	}

	// metrics
	o.Groups[cpu].Metrics.Compute(G)

	// tournaments
	for k := 0; k < np; k++ {
		A := G[P[k][0]]
		B := G[P[k][1]]
		a := G[z+P[k][0]]
		b := G[z+P[k][1]]
		o.Tournament(A, B, a, b, o.Groups[cpu].Metrics)
	}
	return
}
Example #2
0
// Solve solves optimisation problem
func (o *Optimiser) Solve() {

	// benchmark
	if o.Verbose {
		t0 := gotime.Now()
		defer func() {
			io.Pf("\nnfeval = %d\n", o.Nfeval)
			io.Pfblue2("cpu time = %v\n", gotime.Now().Sub(t0))
		}()
	}

	// output
	if o.Output != nil {
		o.Output(0, o.Solutions)
	}

	// perform evolution
	done := make(chan int, o.Ncpu)
	time := 0
	texc := time + o.DtExc
	for time < o.Tf {

		// run groups in parallel. up to exchange time
		for icpu := 0; icpu < o.Ncpu; icpu++ {
			go func(cpu int) {
				nfeval := 0
				for t := time; t < texc; t++ {
					if cpu == 0 && o.Verbose {
						io.Pf("time = %10d\r", t+1)
					}
					nfeval += o.EvolveOneGroup(cpu)
				}
				done <- nfeval
			}(icpu)
		}
		for cpu := 0; cpu < o.Ncpu; cpu++ {
			o.Nfeval += <-done
		}

		// compute metrics with all solutions included
		o.Metrics.Compute(o.Solutions)

		// exchange via tournament
		if o.Ncpu > 1 {
			if o.ExcTour {
				for i := 0; i < o.Ncpu; i++ {
					j := (i + 1) % o.Ncpu
					I := rnd.IntGetUnique(o.Groups[i].Indices, 2)
					J := rnd.IntGetUnique(o.Groups[j].Indices, 2)
					A, B := o.Groups[i].All[I[0]], o.Groups[i].All[I[1]]
					a, b := o.Groups[j].All[J[0]], o.Groups[j].All[J[1]]
					o.Tournament(A, B, a, b, o.Metrics)
				}
			}

			// exchange one randomly
			if o.ExcOne {
				rnd.IntGetGroups(o.cpupairs, utl.IntRange(o.Ncpu))
				for _, pair := range o.cpupairs {
					i, j := pair[0], pair[1]
					n := utl.Imin(o.Groups[i].Ncur, o.Groups[j].Ncur)
					k := rnd.Int(0, n)
					A := o.Groups[i].All[k]
					B := o.Groups[j].All[k]
					B.CopyInto(o.tmp)
					A.CopyInto(B)
					o.tmp.CopyInto(A)
				}
			}
		}

		// update time variables
		time += o.DtExc
		texc += o.DtExc
		time = utl.Imin(time, o.Tf)
		texc = utl.Imin(texc, o.Tf)

		// output
		if o.Output != nil {
			o.Output(time, o.Solutions)
		}
	}
}