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Particle swarm optimization: Difference between revisions

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Particle swarm optimization (view source)

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</p>
<br><br>
 
=={{header|C sharp|C#}}==
{{trans|java}}
<syntaxhighlight lang="csharp">using System;
 
namespace ParticleSwarmOptimization {
public struct Parameters {
public double omega, phip, phig;
 
public Parameters(double omega, double phip, double phig) : this() {
this.omega = omega;
this.phip = phip;
this.phig = phig;
}
}
 
public struct State {
public int iter;
public double[] gbpos;
public double gbval;
public double[] min;
public double[] max;
public Parameters parameters;
public double[][] pos;
public double[][] vel;
public double[][] bpos;
public double[] bval;
public int nParticles;
public int nDims;
 
public State(int iter, double[] gbpos, double gbval, double[] min, double[] max, Parameters parameters, double[][] pos, double[][] vel, double[][] bpos, double[] bval, int nParticles, int nDims) : this() {
this.iter = iter;
this.gbpos = gbpos;
this.gbval = gbval;
this.min = min;
this.max = max;
this.parameters = parameters;
this.pos = pos;
this.vel = vel;
this.bpos = bpos;
this.bval = bval;
this.nParticles = nParticles;
this.nDims = nDims;
}
 
public void Report(string testfunc) {
Console.WriteLine("Test Function : {0}", testfunc);
Console.WriteLine("Iterations : {0}", iter);
Console.WriteLine("Global Best Position : {0}", string.Join(", ", gbpos));
Console.WriteLine("Global Best Value : {0}", gbval);
}
}
 
class Program {
public static State PsoInit(double[] min, double[] max, Parameters parameters, int nParticles) {
var nDims = min.Length;
double[][] pos = new double[nParticles][];
for (int i = 0; i < nParticles; i++) {
pos[i] = new double[min.Length];
min.CopyTo(pos[i], 0);
}
double[][] vel = new double[nParticles][];
for (int i = 0; i < nParticles; i++) {
vel[i] = new double[nDims];
}
double[][] bpos = new double[nParticles][];
for (int i = 0; i < nParticles; i++) {
bpos[i] = new double[min.Length];
min.CopyTo(bpos[i], 0);
}
double[] bval = new double[nParticles];
for (int i = 0; i < nParticles; i++) {
bval[i] = double.PositiveInfinity;
}
int iter = 0;
double[] gbpos = new double[nDims];
for (int i = 0; i < nDims; i++) {
gbpos[i] = double.PositiveInfinity;
}
double gbval = double.PositiveInfinity;
 
return new State(iter, gbpos, gbval, min, max, parameters, pos, vel, bpos, bval, nParticles, nDims);
}
 
static Random r = new Random();
 
public static State Pso(Func<double[], double> fn, State y) {
var p = y.parameters;
double[] v = new double[y.nParticles];
double[][] bpos = new double[y.nParticles][];
for (int i = 0; i < y.nParticles; i++) {
bpos[i] = new double[y.min.Length];
y.min.CopyTo(bpos[i], 0);
}
double[] bval = new double[y.nParticles];
double[] gbpos = new double[y.nDims];
double gbval = double.PositiveInfinity;
for (int j = 0; j < y.nParticles; j++) {
// evaluate
v[j] = fn.Invoke(y.pos[j]);
// update
if (v[j] < y.bval[j]) {
y.pos[j].CopyTo(bpos[j], 0);
bval[j] = v[j];
}
else {
y.bpos[j].CopyTo(bpos[j], 0);
bval[j] = y.bval[j];
}
if (bval[j] < gbval) {
gbval = bval[j];
bpos[j].CopyTo(gbpos, 0);
}
}
double rg = r.NextDouble();
double[][] pos = new double[y.nParticles][];
double[][] vel = new double[y.nParticles][];
for (int i = 0; i < y.nParticles; i++) {
pos[i] = new double[y.nDims];
vel[i] = new double[y.nDims];
}
for (int j = 0; j < y.nParticles; j++) {
// migrate
double rp = r.NextDouble();
bool ok = true;
for (int k = 0; k < y.nDims; k++) {
vel[j][k] = 0.0;
pos[j][k] = 0.0;
}
for (int k = 0; k < y.nDims; k++) {
vel[j][k] = p.omega * y.vel[j][k] +
p.phip * rp * (bpos[j][k] - y.pos[j][k]) +
p.phig * rg * (gbpos[k] - y.pos[j][k]);
pos[j][k] = y.pos[j][k] + vel[j][k];
ok = ok && y.min[k] < pos[j][k] && y.max[k] > pos[j][k];
}
if (!ok) {
for (int k = 0; k < y.nDims; k++) {
pos[j][k] = y.min[k] + (y.max[k] - y.min[k]) * r.NextDouble();
}
}
}
var iter = 1 + y.iter;
return new State(iter, gbpos, gbval, y.min, y.max, y.parameters, pos, vel, bpos, bval, y.nParticles, y.nDims);
}
 
public static State Iterate(Func<double[], double> fn, int n, State y) {
State r = y;
if (n == int.MaxValue) {
State old = y;
while (true) {
r = Pso(fn, r);
if (r.Equals(old)) break;
old = r;
}
}
else {
for (int i = 0; i < n; i++) {
r = Pso(fn, r);
}
}
return r;
}
 
public static double Mccormick(double[] x) {
var a = x[0];
var b = x[1];
return Math.Sin(a + b) + (a - b) * (a - b) + 1.0 + 2.5 * b - 1.5 * a;
}
 
public static double Michalewicz(double[] x) {
int m = 10;
int d = x.Length;
double sum = 0.0;
for (int i = 1; i < d; i++) {
var j = x[i - 1];
var k = Math.Sin(i * j * j / Math.PI);
sum += Math.Sin(j) * Math.Pow(k, 2.0 * m);
}
return -sum;
}
 
static void Main(string[] args) {
var state = PsoInit(
new double[] { -1.5, -3.0 },
new double[] { 4.0, 4.0 },
new Parameters(0.0, 0.6, 0.3),
100
);
state = Iterate(Mccormick, 40, state);
state.Report("McCormick");
Console.WriteLine("f(-.54719, -1.54719) : {0}", Mccormick(new double[] { -.54719, -1.54719 }));
Console.WriteLine();
 
state = PsoInit(
new double[] { -0.0, -0.0 },
new double[] { Math.PI, Math.PI },
new Parameters(0.3, 0.3, 0.3),
1000
);
state = Iterate(Michalewicz, 30, state);
state.Report("Michalewicz (2D)");
Console.WriteLine("f(2.20, 1.57) : {0}", Michalewicz(new double[] { 2.20, 1.57 }));
}
}
}</syntaxhighlight>
{{out}}
<pre>Test Function : McCormick
Iterations : 40
Global Best Position : -0.546850526417689, -1.54649614884518
Global Best Value : -1.91322235333426
f(-.54719, -1.54719) : -1.91322295488227
 
Test Function : Michalewicz (2D)
Iterations : 30
Global Best Position : 2.20290514143486, 2.20798457238775
Global Best Value : -0.801303410096221
f(2.20, 1.57) : -0.801166387820286</pre>
 
=={{header|C++}}==
{{trans|D}}
<langsyntaxhighlight lang="cpp">#include <algorithm>
#include <functional>
#include <iostream>
Line 317 ⟶ 535:
state.report("Michalewicz (2D)");
std::cout << "f(2.20, 1.57) : " << michalewicz({ 2.2, 1.57 }) << '\n';
}</langsyntaxhighlight>
{{out}}
<pre>Test Function : McCormick
Line 330 ⟶ 548:
Global Best Value : -0.801303
f(2.20, 1.57) : -0.801166</pre>
 
=={{header|C#|C sharp}}==
{{trans|java}}
<lang csharp>using System;
 
namespace ParticleSwarmOptimization {
public struct Parameters {
public double omega, phip, phig;
 
public Parameters(double omega, double phip, double phig) : this() {
this.omega = omega;
this.phip = phip;
this.phig = phig;
}
}
 
public struct State {
public int iter;
public double[] gbpos;
public double gbval;
public double[] min;
public double[] max;
public Parameters parameters;
public double[][] pos;
public double[][] vel;
public double[][] bpos;
public double[] bval;
public int nParticles;
public int nDims;
 
public State(int iter, double[] gbpos, double gbval, double[] min, double[] max, Parameters parameters, double[][] pos, double[][] vel, double[][] bpos, double[] bval, int nParticles, int nDims) : this() {
this.iter = iter;
this.gbpos = gbpos;
this.gbval = gbval;
this.min = min;
this.max = max;
this.parameters = parameters;
this.pos = pos;
this.vel = vel;
this.bpos = bpos;
this.bval = bval;
this.nParticles = nParticles;
this.nDims = nDims;
}
 
public void Report(string testfunc) {
Console.WriteLine("Test Function : {0}", testfunc);
Console.WriteLine("Iterations : {0}", iter);
Console.WriteLine("Global Best Position : {0}", string.Join(", ", gbpos));
Console.WriteLine("Global Best Value : {0}", gbval);
}
}
 
class Program {
public static State PsoInit(double[] min, double[] max, Parameters parameters, int nParticles) {
var nDims = min.Length;
double[][] pos = new double[nParticles][];
for (int i = 0; i < nParticles; i++) {
pos[i] = new double[min.Length];
min.CopyTo(pos[i], 0);
}
double[][] vel = new double[nParticles][];
for (int i = 0; i < nParticles; i++) {
vel[i] = new double[nDims];
}
double[][] bpos = new double[nParticles][];
for (int i = 0; i < nParticles; i++) {
bpos[i] = new double[min.Length];
min.CopyTo(bpos[i], 0);
}
double[] bval = new double[nParticles];
for (int i = 0; i < nParticles; i++) {
bval[i] = double.PositiveInfinity;
}
int iter = 0;
double[] gbpos = new double[nDims];
for (int i = 0; i < nDims; i++) {
gbpos[i] = double.PositiveInfinity;
}
double gbval = double.PositiveInfinity;
 
return new State(iter, gbpos, gbval, min, max, parameters, pos, vel, bpos, bval, nParticles, nDims);
}
 
static Random r = new Random();
 
public static State Pso(Func<double[], double> fn, State y) {
var p = y.parameters;
double[] v = new double[y.nParticles];
double[][] bpos = new double[y.nParticles][];
for (int i = 0; i < y.nParticles; i++) {
bpos[i] = new double[y.min.Length];
y.min.CopyTo(bpos[i], 0);
}
double[] bval = new double[y.nParticles];
double[] gbpos = new double[y.nDims];
double gbval = double.PositiveInfinity;
for (int j = 0; j < y.nParticles; j++) {
// evaluate
v[j] = fn.Invoke(y.pos[j]);
// update
if (v[j] < y.bval[j]) {
y.pos[j].CopyTo(bpos[j], 0);
bval[j] = v[j];
}
else {
y.bpos[j].CopyTo(bpos[j], 0);
bval[j] = y.bval[j];
}
if (bval[j] < gbval) {
gbval = bval[j];
bpos[j].CopyTo(gbpos, 0);
}
}
double rg = r.NextDouble();
double[][] pos = new double[y.nParticles][];
double[][] vel = new double[y.nParticles][];
for (int i = 0; i < y.nParticles; i++) {
pos[i] = new double[y.nDims];
vel[i] = new double[y.nDims];
}
for (int j = 0; j < y.nParticles; j++) {
// migrate
double rp = r.NextDouble();
bool ok = true;
for (int k = 0; k < y.nDims; k++) {
vel[j][k] = 0.0;
pos[j][k] = 0.0;
}
for (int k = 0; k < y.nDims; k++) {
vel[j][k] = p.omega * y.vel[j][k] +
p.phip * rp * (bpos[j][k] - y.pos[j][k]) +
p.phig * rg * (gbpos[k] - y.pos[j][k]);
pos[j][k] = y.pos[j][k] + vel[j][k];
ok = ok && y.min[k] < pos[j][k] && y.max[k] > pos[j][k];
}
if (!ok) {
for (int k = 0; k < y.nDims; k++) {
pos[j][k] = y.min[k] + (y.max[k] - y.min[k]) * r.NextDouble();
}
}
}
var iter = 1 + y.iter;
return new State(iter, gbpos, gbval, y.min, y.max, y.parameters, pos, vel, bpos, bval, y.nParticles, y.nDims);
}
 
public static State Iterate(Func<double[], double> fn, int n, State y) {
State r = y;
if (n == int.MaxValue) {
State old = y;
while (true) {
r = Pso(fn, r);
if (r.Equals(old)) break;
old = r;
}
}
else {
for (int i = 0; i < n; i++) {
r = Pso(fn, r);
}
}
return r;
}
 
public static double Mccormick(double[] x) {
var a = x[0];
var b = x[1];
return Math.Sin(a + b) + (a - b) * (a - b) + 1.0 + 2.5 * b - 1.5 * a;
}
 
public static double Michalewicz(double[] x) {
int m = 10;
int d = x.Length;
double sum = 0.0;
for (int i = 1; i < d; i++) {
var j = x[i - 1];
var k = Math.Sin(i * j * j / Math.PI);
sum += Math.Sin(j) * Math.Pow(k, 2.0 * m);
}
return -sum;
}
 
static void Main(string[] args) {
var state = PsoInit(
new double[] { -1.5, -3.0 },
new double[] { 4.0, 4.0 },
new Parameters(0.0, 0.6, 0.3),
100
);
state = Iterate(Mccormick, 40, state);
state.Report("McCormick");
Console.WriteLine("f(-.54719, -1.54719) : {0}", Mccormick(new double[] { -.54719, -1.54719 }));
Console.WriteLine();
 
state = PsoInit(
new double[] { -0.0, -0.0 },
new double[] { Math.PI, Math.PI },
new Parameters(0.3, 0.3, 0.3),
1000
);
state = Iterate(Michalewicz, 30, state);
state.Report("Michalewicz (2D)");
Console.WriteLine("f(2.20, 1.57) : {0}", Michalewicz(new double[] { 2.20, 1.57 }));
}
}
}</lang>
{{out}}
<pre>Test Function : McCormick
Iterations : 40
Global Best Position : -0.546850526417689, -1.54649614884518
Global Best Value : -1.91322235333426
f(-.54719, -1.54719) : -1.91322295488227
 
Test Function : Michalewicz (2D)
Iterations : 30
Global Best Position : 2.20290514143486, 2.20798457238775
Global Best Value : -0.801303410096221
f(2.20, 1.57) : -0.801166387820286</pre>
 
=={{header|D}}==
{{trans|Kotlin}}
<langsyntaxhighlight Dlang="d">import std.math;
import std.random;
import std.stdio;
Line 716:
state.report("Michalewicz (2D)");
writefln("f(2.20, 1.57) : %.16f", michalewicz([2.2, 1.57]));
}</langsyntaxhighlight>
{{out}}
<pre>Test Function : McCormick
Line 732:
=={{header|Go}}==
{{trans|Kotlin}}
<langsyntaxhighlight lang="go">package main
 
import (
Line 888:
st.report("Michalewicz (2D)")
fmt.Println("f(2.20, 1.57) :", michalewicz([]float64{2.2, 1.57}))
</syntaxhighlight>
</lang>
 
{{out}}
Line 907:
 
=={{header|J}}==
<langsyntaxhighlight Jlang="j">load 'format/printf'
 
pso_init =: verb define
Line 951:
)
 
reportState=: 'Iteration: %j\nGlobalBestPosition: %j\nGlobalBestValue: %j\n' printf 3&{.</langsyntaxhighlight>
Apply to McCormick Function:<langsyntaxhighlight Jlang="j"> require 'trig'
mccormick =: sin@(+/) + *:@(-/) + 1 + _1.5 2.5 +/@:* ]
 
Line 965:
Iteration: 40
GlobalBestPosition: _0.547399 _1.54698
GlobalBestValue: _1.91322</langsyntaxhighlight>
Apply to Michalewicz Function:
<langsyntaxhighlight Jlang="j"> michalewicz =: 3 : '- +/ (sin y) * 20 ^~ sin (>: i. #y) * (*:y) % pi'
michalewicz =: [: -@(+/) sin * 20 ^~ sin@(pi %~ >:@i.@# * *:) NB. tacit equivalent
Line 980:
Iteration: 30
GlobalBestPosition: 2.20296 1.57083
GlobalBestValue: _1.8013</langsyntaxhighlight>
 
=={{header|JavaScript}}==
 
Translation of [[Particle_Swarm_Optimization#J|J]].
 
<lang JavaScript>function pso_init(y) {
var nDims= y.min.length;
var pos=[], vel=[], bpos=[], bval=[];
for (var j= 0; j<y.nParticles; j++) {
pos[j]= bpos[j]= y.min;
var v= []; for (var k= 0; k<nDims; k++) v[k]= 0;
vel[j]= v;
bval[j]= Infinity}
return {
iter: 0,
gbpos: Infinity,
gbval: Infinity,
min: y.min,
max: y.max,
parameters: y.parameters,
pos: pos,
vel: vel,
bpos: bpos,
bval: bval,
nParticles: y.nParticles,
nDims: nDims}
}
 
function pso(fn, state) {
var y= state;
var p= y.parameters;
var val=[], bpos=[], bval=[], gbval= Infinity, gbpos=[];
for (var j= 0; j<y.nParticles; j++) {
// evaluate
val[j]= fn.apply(null, y.pos[j]);
// update
if (val[j] < y.bval[j]) {
bpos[j]= y.pos[j];
bval[j]= val[j];
} else {
bpos[j]= y.bpos[j];
bval[j]= y.bval[j]}
if (bval[j] < gbval) {
gbval= bval[j];
gbpos= bpos[j]}}
var rg= Math.random(), vel=[], pos=[];
for (var j= 0; j<y.nParticles; j++) {
// migrate
var rp= Math.random(), ok= true;
vel[j]= [];
pos[j]= [];
for (var k= 0; k < y.nDims; k++) {
vel[j][k]= p.omega*y.vel[j][k] + p.phip*rp*(bpos[j]-y.pos[j]) + p.phig*rg*(gbpos-y.pos[j]);
pos[j][k]= y.pos[j]+vel[j][k];
ok= ok && y.min[k]<pos[j][k] && y.max>pos[j][k];}
if (!ok)
for (var k= 0; k < y.nDims; k++)
pos[j][k]= y.min[k] + (y.max[k]-y.min[k])*Math.random()}
return {
iter: 1+y.iter,
gbpos: gbpos,
gbval: gbval,
min: y.min,
max: y.max,
parameters: y.parameters,
pos: pos,
vel: vel,
bpos: bpos,
bval: bval,
nParticles: y.nParticles,
nDims: y.nDims}
}
 
function display(text) {
if (document) {
var o= document.getElementById('o');
if (!o) {
o= document.createElement('pre');
o.id= 'o';
document.body.appendChild(o)}
o.innerHTML+= text+'\n';
window.scrollTo(0,document.body.scrollHeight);
}
if (console.log) console.log(text)
}
 
function reportState(state) {
var y= state;
display('');
display('Iteration: '+y.iter);
display('GlobalBestPosition: '+y.gbpos);
display('GlobalBestValue: '+y.gbval);
}
 
function repeat(fn, n, y) {
var r=y, old= y;
if (Infinity == n)
while ((r= fn(r)) != old) old= r;
else
for (var j= 0; j<n; j++) r= fn(r);
return r
}
 
function mccormick(a,b) {
return Math.sin(a+b) + Math.pow(a-b,2) + (1 + 2.5*b - 1.5*a)
}
 
state= pso_init({
min: [-1.5,-3], max:[4,4],
parameters: {omega: 0, phip: 0.6, phig: 0.3},
nParticles: 100});
 
reportState(state);
 
state= repeat(function(y){return pso(mccormick,y)}, 40, state);
 
reportState(state);</lang>
 
Example displayed result (random numbers are involved so there will be a bit of variance between repeated runs:
 
<lang Javascript>
Iteration: 0
GlobalBestPosition: Infinity
GlobalBestValue: Infinity
 
Iteration: 40
GlobalBestPosition: -0.5134004259016365,-1.5512442672625184
GlobalBestValue: -1.9114053788600853</lang>
 
=={{header|Java}}==
{{trans|Kotlin}}
<langsyntaxhighlight lang="java">import java.util.Arrays;
import java.util.Objects;
import java.util.Random;
Line 1,305 ⟶ 1,177:
System.out.printf("f(2.20, 1.57) : %.15f\n", michalewicz(new double[]{2.20, 1.57}));
}
}</langsyntaxhighlight>
{{out}}
<pre>Test Function : McCormick
Line 1,318 ⟶ 1,190:
Global Best value : -0.801303410098550
f(2.20, 1.57) : -0.801166387820286</pre>
 
=={{header|JavaScript}}==
 
Translation of [[Particle_Swarm_Optimization#J|J]].
 
<syntaxhighlight lang="javascript">function pso_init(y) {
var nDims= y.min.length;
var pos=[], vel=[], bpos=[], bval=[];
for (var j= 0; j<y.nParticles; j++) {
pos[j]= bpos[j]= y.min;
var v= []; for (var k= 0; k<nDims; k++) v[k]= 0;
vel[j]= v;
bval[j]= Infinity}
return {
iter: 0,
gbpos: Infinity,
gbval: Infinity,
min: y.min,
max: y.max,
parameters: y.parameters,
pos: pos,
vel: vel,
bpos: bpos,
bval: bval,
nParticles: y.nParticles,
nDims: nDims}
}
 
function pso(fn, state) {
var y= state;
var p= y.parameters;
var val=[], bpos=[], bval=[], gbval= Infinity, gbpos=[];
for (var j= 0; j<y.nParticles; j++) {
// evaluate
val[j]= fn.apply(null, y.pos[j]);
// update
if (val[j] < y.bval[j]) {
bpos[j]= y.pos[j];
bval[j]= val[j];
} else {
bpos[j]= y.bpos[j];
bval[j]= y.bval[j]}
if (bval[j] < gbval) {
gbval= bval[j];
gbpos= bpos[j]}}
var rg= Math.random(), vel=[], pos=[];
for (var j= 0; j<y.nParticles; j++) {
// migrate
var rp= Math.random(), ok= true;
vel[j]= [];
pos[j]= [];
for (var k= 0; k < y.nDims; k++) {
vel[j][k]= p.omega*y.vel[j][k] + p.phip*rp*(bpos[j]-y.pos[j]) + p.phig*rg*(gbpos-y.pos[j]);
pos[j][k]= y.pos[j]+vel[j][k];
ok= ok && y.min[k]<pos[j][k] && y.max>pos[j][k];}
if (!ok)
for (var k= 0; k < y.nDims; k++)
pos[j][k]= y.min[k] + (y.max[k]-y.min[k])*Math.random()}
return {
iter: 1+y.iter,
gbpos: gbpos,
gbval: gbval,
min: y.min,
max: y.max,
parameters: y.parameters,
pos: pos,
vel: vel,
bpos: bpos,
bval: bval,
nParticles: y.nParticles,
nDims: y.nDims}
}
 
function display(text) {
if (document) {
var o= document.getElementById('o');
if (!o) {
o= document.createElement('pre');
o.id= 'o';
document.body.appendChild(o)}
o.innerHTML+= text+'\n';
window.scrollTo(0,document.body.scrollHeight);
}
if (console.log) console.log(text)
}
 
function reportState(state) {
var y= state;
display('');
display('Iteration: '+y.iter);
display('GlobalBestPosition: '+y.gbpos);
display('GlobalBestValue: '+y.gbval);
}
 
function repeat(fn, n, y) {
var r=y, old= y;
if (Infinity == n)
while ((r= fn(r)) != old) old= r;
else
for (var j= 0; j<n; j++) r= fn(r);
return r
}
 
function mccormick(a,b) {
return Math.sin(a+b) + Math.pow(a-b,2) + (1 + 2.5*b - 1.5*a)
}
 
state= pso_init({
min: [-1.5,-3], max:[4,4],
parameters: {omega: 0, phip: 0.6, phig: 0.3},
nParticles: 100});
 
reportState(state);
 
state= repeat(function(y){return pso(mccormick,y)}, 40, state);
 
reportState(state);</syntaxhighlight>
 
Example displayed result (random numbers are involved so there will be a bit of variance between repeated runs:
 
<syntaxhighlight lang="javascript">
Iteration: 0
GlobalBestPosition: Infinity
GlobalBestValue: Infinity
 
Iteration: 40
GlobalBestPosition: -0.5134004259016365,-1.5512442672625184
GlobalBestValue: -1.9114053788600853</syntaxhighlight>
 
=={{header|Julia}}==
<langsyntaxhighlight lang="julia">using Optim
 
const mcclow = [-1.5, -3.0]
Line 1,339:
println(optimize(michalewicz, x0, ParticleSwarm(;lower=miclow, upper=micupp, n_particles=npar[2])))
@time optimize(michalewicz, x0, ParticleSwarm(;lower=miclow, upper=micupp, n_particles=npar[2]))
</langsyntaxhighlight>{{out}}
<pre>
Results of Optimization Algorithm
Line 1,382:
=={{header|Kotlin}}==
{{trans|JavaScript}}
<langsyntaxhighlight lang="scala">// version 1.1.51
 
import java.util.Random
Line 1,538:
state.report("Michalewicz (2D)")
println("f(2.20, 1.57) : ${michalewicz(doubleArrayOf(2.2, 1.57))}")
}</langsyntaxhighlight>
 
Sample output:
Line 1,554:
f(2.20, 1.57) : -1.801140718473825
</pre>
 
=={{header|Nim}}==
{{trans|Kotlin}}
<syntaxhighlight lang="nim">import math, random, sequtils, sugar
 
type
 
Func = seq[float] -> float
 
Parameters = tuple[omega, phip, phig: float]
 
State = object
iter: int
gbpos: seq[float]
gbval: float
min, max: seq[float]
parameters: Parameters
pos, vel, bpos: seq[seq[float]]
bval: seq[float]
nParticles, nDims: int
 
 
func initState(min, max: seq[float]; parameters: Parameters; nParticles: int): State =
let nDims = min.len
State(iter: 0,
gbpos: repeat(Inf, nDims),
gbval: Inf,
min: min,
max: max,
parameters: parameters,
pos: repeat(min, nParticles),
vel: newSeqWith(nParticles,
newSeq[float](nDims)),
bpos: repeat(min, nParticles),
bval: repeat(Inf, nParticles),
nParticles: nParticles,
nDims: nDims)
 
 
proc report(state: State; testFunc: string) =
echo "Test Function: ", testfunc
echo "Iterations: ", state.iter
echo "Global Best Position: ", state.gbpos
echo "Global Best Value: ", state.gbval
 
 
proc pso(fn: Func; y: State): State =
let p = y.parameters
var v = newSeq[float](y.nParticles)
var bpos = repeat(y.min, y.nParticles)
var bval = newSeq[float](y.nParticles)
var gbpos = newSeq[float](y.nDims)
var gbval = Inf
 
for j in 0..<y.nParticles:
# evaluate.
v[j] = fn(y.pos[j])
# update.
if v[j] < y.bval[j]:
bpos[j] = y.pos[j]
bval[j] = v[j]
else:
bpos[j] = y.bpos[j]
bval[j] = y.bval[j]
if bval[j] < gbval:
gbval = bval[j]
gbpos = bpos[j]
 
let rg = rand(1.0)
var pos = newSeqWith(y.nParticles, newSeq[float](y.nDims))
var vel = newSeqWith(y.nParticles, newSeq[float](y.nDims))
for j in 0..<y.nParticles:
# migrate.
let rp = rand(1.0)
var ok = true
for k in 0..<y.nDims:
vel[j][k] = p.omega * y.vel[j][k] +
p.phip * rp * (bpos[j][k] - y.pos[j][k]) +
p.phig * rg * (gbpos[k] - y.pos[j][k])
pos[j][k] = y.pos[j][k] + vel[j][k]
ok = ok and y.min[k] < pos[j][k] and y.max[k] > pos[j][k]
if not ok:
for k in 0..<y.nDims:
pos[j][k]= y.min[k] + (y.max[k] - y.min[k]) * rand(1.0)
 
result = State(iter: 1 + y.iter,
gbpos: gbpos,
gbval: gbval,
min: y.min,
max: y.max,
parameters: y.parameters,
pos: pos,
vel: vel,
bpos: bpos,
bval: bval,
nParticles: y.nParticles,
nDims: y.nDims)
 
 
proc iterate(fn: Func; n: int; y: State): State =
result = y
if n == int.high:
while true:
let old = result
result = pso(fn, result)
if result == old: break
else:
for _ in 1..n:
result = pso(fn, result)
 
 
func mccormick(x: seq[float]): float =
let a = x[0]
let b = x[1]
result = sin(a + b) + (a - b) * (a - b) + 1.0 + 2.5 * b - 1.5 * a
 
 
func michalewicz(x: seq[float]): float =
const M = 10
for i in 1..x.len:
let j = x[i - 1]
let k = sin(i.toFloat * j * j / PI)
result -= sin(j) * k^(2 * M)
 
 
randomize()
 
var state = initState(min = @[-1.5, -3],
max = @[4.0, 4.0],
parameters = (0.0, 0.6, 0.3),
nParticles = 100)
 
state = iterate(mccormick, 40, state)
state.report("McCormick")
echo "f(-.54719, -1.54719): ", mccormick(@[-0.54719, -1.54719])
echo()
state = initState(min = @[0.0, 0.0],
max = @[PI, PI],
parameters = (0.3, 0.3, 0.3),
nParticles = 1000)
state = iterate(michalewicz, 30, state)
state.report("Michalewicz (2D)")
echo "f(2.20, 1.57): ", michalewicz(@[2.2, 1.57])</syntaxhighlight>
 
{{out}}
<pre>Test Function: McCormick
Iterations: 40
Global Best Position: @[-0.5470347980396687, -1.547176688676891]
Global Best Value: -1.913222920248667
f(-.54719, -1.54719): -1.913222954882274
 
Test Function: Michalewicz (2D)
Iterations: 30
Global Best Position: @[2.202898715299719, 1.570804023976923]
Global Best Value: -1.801303406946448
f(2.20, 1.57): -1.801140718473825</pre>
 
=={{header|ooRexx}}==
<langsyntaxhighlight lang="oorexx">/* REXX ---------------------------------------------------------------
* Test for McCormick function
*--------------------------------------------------------------------*/
Line 1,591 ⟶ 1,747:
res=rxcalcsin(x+y,16,'R')+(x-y)**2-1.5*x+2.5*y+1
Return res
::requires rxmath library</langsyntaxhighlight>
{{out}}
<pre>-1.5 -2.5 -1.243197504692072
Line 1,609 ⟶ 1,765:
and differs from published -1.9133</pre>
 
=={{header|PhixPerl}}==
{{trans|KotlinRaku}}
<syntaxhighlight lang="perl">use strict;
<lang Phix>enum OMEGA, PHIP, PHIG
use warnings;
enum ITER,GBPOS,GBVAL,MIN,MAX,PARAMS,POS,VEL,BPOS,BVAL,NPARTICLES,NDIMS
use feature 'say';
 
use constant infPI => 2 1e308*1e308 atan2(1, 0);
use constant Inf => 1e10;
 
sub pso_init {
constant fmt = """
my(%y) = @_;
Test Function : %s
my $d = @{$y{'min'}};
Iterations : %d
my $n = $y{'n'};
Global Best Position : %s
Global Best Value : %f
"""
 
$y{'gbval'} = Inf;
procedure report(sequence state, string testfunc)
$y{'gbpos'} = [(Inf) x $d];
printf(1,fmt,{testfunc,state[ITER],sprint(state[GBPOS]),state[GBVAL]})
$y{'bval'} = [(Inf) x $n];
end procedure
$y{'bpos'} = [($y{'min'}) x $n];
$y{'pos'} = [($y{'min'}) x $n];
$y{'vel'} = [([(0) x $d]) x $n];
 
%y
function psoInit(sequence mins, maxs, params, integer nParticles)
}
integer nDims = length(mins), iter=0
atom gbval = inf
sequence gbpos = repeat(inf,nDims),
pos = repeat(mins,nParticles),
vel = repeat(repeat(0,nDims),nParticles),
bpos = repeat(mins,nParticles),
bval = repeat(inf,nParticles)
return {iter,gbpos,gbval,mins,maxs,params,pos,vel,bpos,bval,nParticles,nDims}
end function
function pso(integer fn, sequence state)
integer particles = state[NPARTICLES],
dims = state[NDIMS]
sequence p = state[PARAMS],
v = repeat(0,particles),
bpos = repeat(state[MIN],particles),
bval = repeat(0,particles),
gbpos = repeat(0,dims)
atom gbval = inf
for j=1 to particles do
-- evaluate
v[j] = call_func(fn,{state[POS][j]})
-- update
if v[j] < state[BVAL][j] then
bpos[j] = state[POS][j]
bval[j] = v[j]
else
bpos[j] = state[BPOS][j]
bval[j] = state[BVAL][j]
end if
if bval[j] < gbval then
gbval = bval[j]
gbpos = bpos[j]
end if
end for
atom rg = rnd()
sequence pos = repeat(repeat(0,dims),particles),
vel = repeat(repeat(0,dims),particles)
for j=1 to particles do
-- migrate
atom rp = rnd()
bool ok = true
vel[j] = repeat(0,dims)
pos[j] = repeat(0,dims)
for k=1 to dims do
vel[j][k] = p[OMEGA] * state[VEL][j][k] +
p[PHIP] * rp * (bpos[j][k] - state[POS][j][k]) +
p[PHIG] * rg * (gbpos[k] - state[POS][j][k])
pos[j][k] = state[POS][j][k] + vel[j][k]
ok = ok and state[MIN][k] < pos[j][k] and state[MAX][k] > pos[j][k]
end for
if not ok then
for k=1 to dims do
pos[j][k]= state[MIN][k] + (state[MAX][k] - state[MIN][k]) * rnd()
end for
end if
end for
integer iter = 1 + state[ITER]
return {iter, gbpos, gbval, state[MIN], state[MAX], state[PARAMS],
pos, vel, bpos, bval, particles, dims}
end function
function iterate(integer fn, n, sequence state)
sequence r = state,
old = state
if n=-1 then
while true do
r = pso(fn, r)
if (r == old) then exit end if
old = r
end while
else
for i=1 to n do
r = pso(fn, r)
end for
end if
return r
end function
function mccormick(sequence x)
atom {a, b} = x
return sin(a + b) + (a - b) * (a - b) + 1.0 + 2.5 * b - 1.5 * a
end function
constant r_mccormick = routine_id("mccormick")
function michalewicz(sequence x)
integer m = 10,
d = length(x)
atom total = 0.0
for i=1 to d do
atom j = x[i],
k = sin(i * j * j / PI)
total += sin(j) * power(k, 2.0 * m)
end for
return -total
end function
constant r_michalewicz = routine_id("michalewicz")
procedure main()
sequence mins = {-1.5, -3.0},
maxs = {4.0, 4.0},
params = {0.0, 0.6, 0.3}
integer nParticles = 100
sequence state = psoInit(mins,maxs,params,nParticles)
state = iterate(r_mccormick, 40, state)
report(state,"McCormick")
atom {x,y} = state[GBPOS]
printf(1,"f(%.4f, %.4f) : %f\n\n",{x,y,mccormick({x,y})})
 
sub pso {
mins = {0.0, 0.0}
maxsmy($fn, =%y) {PI,= PI}@_;
paramsmy =$p {0.3, 0.3, 0.3 = $y{'p'};
nParticlesmy $n = 1000$y{'n'};
my $d = @{$y{'min'}};
state = psoInit(mins,maxs,params,nParticles)
my @bpos = ($y{'min'}) x $n;
state = iterate(r_michalewicz, 30, state)
my $gbval = Inf;
report(state,"Michalewicz (2D)")
{x,y}my $rand_g = state[GBPOS]rand;
my (@pos, @vel, @v, @gbpos, @bval);
printf(1,"f(%.5f, %.5f) : %f\n\n",{x,y,michalewicz({x,y})})
 
end procedure
for my $j (0 .. $n-1) {
main()</lang>
$v[$j] = &$fn(@{$y{'pos'}[$j]}); # evaluate
 
# update
if ($v[$j] < $y{'bval'}[$j]) {
$bpos[$j] = $y{'pos'}[$j];
$bval[$j] = $v[$j];
} else {
$bpos[$j] = $y{'bpos'}[$j];
$bval[$j] = $y{'bval'}[$j];
}
if ($bval[$j] < $gbval) {
@gbpos = @{$bpos[$j]};
$gbval = $bval[$j];
}
}
 
# migrate
for my $j (0 .. $n-1) {
my $rand_p = rand;
my $ok = 1;
for my $k (0 .. $d-1) {
$vel[$j][$k] = $$p{'omega'} * $y{'vel'}[$j][$k]
+ $$p{'phi_p'} * $rand_p * ($bpos[$j][$k] - $y{'pos'}[$j][$k])
+ $$p{'phi_g'} * $rand_g * ($gbpos[$k] - $y{'pos'}[$j][$k]);
$pos[$j][$k] = $y{'pos'}[$j][$k] + $vel[$j][$k];
$ok = ($y{'min'}[$k] < $pos[$j][$k]) && ($pos[$j][$k] < $y{'max'}[$k]) && $ok;
}
next if $ok;
$pos[$j][$_] = $y{'min'}[$_] + ($y{'max'}[$_] - $y{'min'}[$_]) * rand for 0 .. $d-1;
}
return {gbpos => \@gbpos, gbval => $gbval, bpos => \@bpos, bval => \@bval, pos => \@pos, vel => \@vel,
min => $y{'min'}, max => $y{'max'}, p=> $y{'p'}, n => $n};
}
 
sub report {
my($function_name, %state) = @_;
say $function_name;
say 'Global best position: ' . sprintf "%.5f %.5f", @{$state{'gbpos'}};
say 'Global best value: ' . sprintf "%.5f", $state{'gbval'};
say '';
}
 
# McCormick
sub mccormick {
my($a,$b) = @_;
sin($a+$b) + ($a-$b)**2 + (1 + 2.5*$b - 1.5*$a)
}
 
my %state = pso_init( (
min => [-1.5, -3],
max => [4, 4],
n => 100,
p => {omega => 0, phi_p => 0.6, phi_g => 0.3},
) );
%state = %{pso(\&mccormick, %state)} for 1 .. 40;
report('McCormick', %state);
 
# Michalewicz
sub michalewicz {
my(@x) = @_;
my $sum;
my $m = 10;
for my $i (1..@x) {
my $j = $x[$i - 1];
my $k = sin($i * $j**2/PI);
$sum += sin($j) * $k**(2*$m)
}
-$sum
}
 
%state = pso_init( (
min => [0, 0],
max => [PI, PI],
n => 1000,
p => {omega => 0.3, phi_p => 0.3, phi_g => 0.3},
) );
%state = %{pso(\&michalewicz, %state)} for 1 .. 30;
report('Michalewicz', %state);</syntaxhighlight>
{{out}}
<pre>McCormick
Global best position: -0.54675 -1.54665
Global best value: -1.91322
 
Michalewicz
Global best position: 2.20293 1.57080
Global best value: -1.80130</pre>
 
=={{header|Phix}}==
{{trans|Kotlin}}
<!--<syntaxhighlight lang="phix">(phixonline)-->
<span style="color: #008080;">with</span> <span style="color: #008080;">javascript_semantics</span>
<span style="color: #008080;">enum</span> <span style="color: #000000;">OMEGA</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">PHIP</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">PHIG</span>
<span style="color: #008080;">enum</span> <span style="color: #000000;">ITER</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">GBPOS</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">GBVAL</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">MIN</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">MAX</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">PARAMS</span><span style="color: #0000FF;">,</span>
<span style="color: #000000;">POS</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">VEL</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">BPOS</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">BVAL</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">NPARTICLES</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">NDIMS</span>
<span style="color: #008080;">constant</span> <span style="color: #000000;">inf</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">1e308</span><span style="color: #0000FF;">*</span><span style="color: #000000;">1e308</span>
<span style="color: #008080;">constant</span> <span style="color: #000000;">fmt</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">"""
Test Function : %s
Iterations : %d
Global Best Position : %s
Global Best Value : %f
"""</span>
<span style="color: #008080;">procedure</span> <span style="color: #000000;">report</span><span style="color: #0000FF;">(</span><span style="color: #004080;">sequence</span> <span style="color: #000000;">state</span><span style="color: #0000FF;">,</span> <span style="color: #004080;">string</span> <span style="color: #000000;">testfunc</span><span style="color: #0000FF;">)</span>
<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">fmt</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">testfunc</span><span style="color: #0000FF;">,</span><span style="color: #000000;">state</span><span style="color: #0000FF;">[</span><span style="color: #000000;">ITER</span><span style="color: #0000FF;">],</span><span style="color: #7060A8;">sprint</span><span style="color: #0000FF;">(</span><span style="color: #000000;">state</span><span style="color: #0000FF;">[</span><span style="color: #000000;">GBPOS</span><span style="color: #0000FF;">]),</span><span style="color: #000000;">state</span><span style="color: #0000FF;">[</span><span style="color: #000000;">GBVAL</span><span style="color: #0000FF;">]})</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">procedure</span>
<span style="color: #008080;">function</span> <span style="color: #000000;">psoInit</span><span style="color: #0000FF;">(</span><span style="color: #004080;">sequence</span> <span style="color: #000000;">mins</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">maxs</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">params</span><span style="color: #0000FF;">,</span> <span style="color: #004080;">integer</span> <span style="color: #000000;">nParticles</span><span style="color: #0000FF;">)</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">nDims</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">mins</span><span style="color: #0000FF;">),</span> <span style="color: #000000;">iter</span><span style="color: #0000FF;">=</span><span style="color: #000000;">0</span>
<span style="color: #004080;">atom</span> <span style="color: #000000;">gbval</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">inf</span>
<span style="color: #004080;">sequence</span> <span style="color: #000000;">gbpos</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #000000;">inf</span><span style="color: #0000FF;">,</span><span style="color: #000000;">nDims</span><span style="color: #0000FF;">),</span>
<span style="color: #000000;">pos</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #000000;">mins</span><span style="color: #0000FF;">,</span><span style="color: #000000;">nParticles</span><span style="color: #0000FF;">),</span>
<span style="color: #000000;">vel</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #000000;">nDims</span><span style="color: #0000FF;">),</span><span style="color: #000000;">nParticles</span><span style="color: #0000FF;">),</span>
<span style="color: #000000;">bpos</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #000000;">mins</span><span style="color: #0000FF;">,</span><span style="color: #000000;">nParticles</span><span style="color: #0000FF;">),</span>
<span style="color: #000000;">bval</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #000000;">inf</span><span style="color: #0000FF;">,</span><span style="color: #000000;">nParticles</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">return</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">iter</span><span style="color: #0000FF;">,</span><span style="color: #000000;">gbpos</span><span style="color: #0000FF;">,</span><span style="color: #000000;">gbval</span><span style="color: #0000FF;">,</span><span style="color: #000000;">mins</span><span style="color: #0000FF;">,</span><span style="color: #000000;">maxs</span><span style="color: #0000FF;">,</span><span style="color: #000000;">params</span><span style="color: #0000FF;">,</span><span style="color: #000000;">pos</span><span style="color: #0000FF;">,</span><span style="color: #000000;">vel</span><span style="color: #0000FF;">,</span><span style="color: #000000;">bpos</span><span style="color: #0000FF;">,</span><span style="color: #000000;">bval</span><span style="color: #0000FF;">,</span><span style="color: #000000;">nParticles</span><span style="color: #0000FF;">,</span><span style="color: #000000;">nDims</span><span style="color: #0000FF;">}</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
<span style="color: #008080;">function</span> <span style="color: #000000;">pso</span><span style="color: #0000FF;">(</span><span style="color: #004080;">integer</span> <span style="color: #000000;">fn</span><span style="color: #0000FF;">,</span> <span style="color: #004080;">sequence</span> <span style="color: #000000;">state</span><span style="color: #0000FF;">)</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">particles</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">state</span><span style="color: #0000FF;">[</span><span style="color: #000000;">NPARTICLES</span><span style="color: #0000FF;">],</span>
<span style="color: #000000;">dims</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">state</span><span style="color: #0000FF;">[</span><span style="color: #000000;">NDIMS</span><span style="color: #0000FF;">]</span>
<span style="color: #004080;">sequence</span> <span style="color: #000000;">p</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">state</span><span style="color: #0000FF;">[</span><span style="color: #000000;">PARAMS</span><span style="color: #0000FF;">],</span>
<span style="color: #000000;">v</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #000000;">particles</span><span style="color: #0000FF;">),</span>
<span style="color: #000000;">bpos</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #000000;">state</span><span style="color: #0000FF;">[</span><span style="color: #000000;">MIN</span><span style="color: #0000FF;">],</span><span style="color: #000000;">particles</span><span style="color: #0000FF;">),</span>
<span style="color: #000000;">bval</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #000000;">particles</span><span style="color: #0000FF;">),</span>
<span style="color: #000000;">gbpos</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #000000;">dims</span><span style="color: #0000FF;">)</span>
<span style="color: #004080;">atom</span> <span style="color: #000000;">gbval</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">inf</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">j</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">particles</span> <span style="color: #008080;">do</span>
<span style="color: #000080;font-style:italic;">-- evaluate</span>
<span style="color: #000000;">v</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">fn</span><span style="color: #0000FF;">(</span><span style="color: #000000;">state</span><span style="color: #0000FF;">[</span><span style="color: #000000;">POS</span><span style="color: #0000FF;">][</span><span style="color: #000000;">j</span><span style="color: #0000FF;">])</span>
<span style="color: #000080;font-style:italic;">-- update</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">v</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;"><</span> <span style="color: #000000;">state</span><span style="color: #0000FF;">[</span><span style="color: #000000;">BVAL</span><span style="color: #0000FF;">][</span><span style="color: #000000;">j</span><span style="color: #0000FF;">]</span> <span style="color: #008080;">then</span>
<span style="color: #000000;">bpos</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">state</span><span style="color: #0000FF;">[</span><span style="color: #000000;">POS</span><span style="color: #0000FF;">][</span><span style="color: #000000;">j</span><span style="color: #0000FF;">]</span>
<span style="color: #000000;">bval</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">v</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">]</span>
<span style="color: #008080;">else</span>
<span style="color: #000000;">bpos</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">state</span><span style="color: #0000FF;">[</span><span style="color: #000000;">BPOS</span><span style="color: #0000FF;">][</span><span style="color: #000000;">j</span><span style="color: #0000FF;">]</span>
<span style="color: #000000;">bval</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">state</span><span style="color: #0000FF;">[</span><span style="color: #000000;">BVAL</span><span style="color: #0000FF;">][</span><span style="color: #000000;">j</span><span style="color: #0000FF;">]</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">bval</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;"><</span> <span style="color: #000000;">gbval</span> <span style="color: #008080;">then</span>
<span style="color: #000000;">gbval</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">bval</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">]</span>
<span style="color: #000000;">gbpos</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">bpos</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">]</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<span style="color: #004080;">atom</span> <span style="color: #000000;">rg</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">rnd</span><span style="color: #0000FF;">()</span>
<span style="color: #004080;">sequence</span> <span style="color: #000000;">pos</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #000000;">dims</span><span style="color: #0000FF;">),</span><span style="color: #000000;">particles</span><span style="color: #0000FF;">),</span>
<span style="color: #000000;">vel</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #000000;">dims</span><span style="color: #0000FF;">),</span><span style="color: #000000;">particles</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">j</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">particles</span> <span style="color: #008080;">do</span>
<span style="color: #000080;font-style:italic;">-- migrate</span>
<span style="color: #004080;">atom</span> <span style="color: #000000;">rp</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">rnd</span><span style="color: #0000FF;">()</span>
<span style="color: #004080;">bool</span> <span style="color: #000000;">ok</span> <span style="color: #0000FF;">=</span> <span style="color: #004600;">true</span>
<span style="color: #000000;">vel</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #000000;">dims</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">pos</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #000000;">dims</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">k</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">dims</span> <span style="color: #008080;">do</span>
<span style="color: #000000;">vel</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">][</span><span style="color: #000000;">k</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">p</span><span style="color: #0000FF;">[</span><span style="color: #000000;">OMEGA</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">*</span> <span style="color: #000000;">state</span><span style="color: #0000FF;">[</span><span style="color: #000000;">VEL</span><span style="color: #0000FF;">][</span><span style="color: #000000;">j</span><span style="color: #0000FF;">][</span><span style="color: #000000;">k</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">+</span>
<span style="color: #000000;">p</span><span style="color: #0000FF;">[</span><span style="color: #000000;">PHIP</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">*</span> <span style="color: #000000;">rp</span> <span style="color: #0000FF;">*</span> <span style="color: #0000FF;">(</span><span style="color: #000000;">bpos</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">][</span><span style="color: #000000;">k</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">-</span> <span style="color: #000000;">state</span><span style="color: #0000FF;">[</span><span style="color: #000000;">POS</span><span style="color: #0000FF;">][</span><span style="color: #000000;">j</span><span style="color: #0000FF;">][</span><span style="color: #000000;">k</span><span style="color: #0000FF;">])</span> <span style="color: #0000FF;">+</span>
<span style="color: #000000;">p</span><span style="color: #0000FF;">[</span><span style="color: #000000;">PHIG</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">*</span> <span style="color: #000000;">rg</span> <span style="color: #0000FF;">*</span> <span style="color: #0000FF;">(</span><span style="color: #000000;">gbpos</span><span style="color: #0000FF;">[</span><span style="color: #000000;">k</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">-</span> <span style="color: #000000;">state</span><span style="color: #0000FF;">[</span><span style="color: #000000;">POS</span><span style="color: #0000FF;">][</span><span style="color: #000000;">j</span><span style="color: #0000FF;">][</span><span style="color: #000000;">k</span><span style="color: #0000FF;">])</span>
<span style="color: #000000;">pos</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">][</span><span style="color: #000000;">k</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">state</span><span style="color: #0000FF;">[</span><span style="color: #000000;">POS</span><span style="color: #0000FF;">][</span><span style="color: #000000;">j</span><span style="color: #0000FF;">][</span><span style="color: #000000;">k</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">+</span> <span style="color: #000000;">vel</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">][</span><span style="color: #000000;">k</span><span style="color: #0000FF;">]</span>
<span style="color: #000000;">ok</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">ok</span> <span style="color: #008080;">and</span> <span style="color: #000000;">state</span><span style="color: #0000FF;">[</span><span style="color: #000000;">MIN</span><span style="color: #0000FF;">][</span><span style="color: #000000;">k</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;"><</span> <span style="color: #000000;">pos</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">][</span><span style="color: #000000;">k</span><span style="color: #0000FF;">]</span> <span style="color: #008080;">and</span> <span style="color: #000000;">state</span><span style="color: #0000FF;">[</span><span style="color: #000000;">MAX</span><span style="color: #0000FF;">][</span><span style="color: #000000;">k</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">></span> <span style="color: #000000;">pos</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">][</span><span style="color: #000000;">k</span><span style="color: #0000FF;">]</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<span style="color: #008080;">if</span> <span style="color: #008080;">not</span> <span style="color: #000000;">ok</span> <span style="color: #008080;">then</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">k</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">dims</span> <span style="color: #008080;">do</span>
<span style="color: #000000;">pos</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">][</span><span style="color: #000000;">k</span><span style="color: #0000FF;">]=</span> <span style="color: #000000;">state</span><span style="color: #0000FF;">[</span><span style="color: #000000;">MIN</span><span style="color: #0000FF;">][</span><span style="color: #000000;">k</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">+</span> <span style="color: #0000FF;">(</span><span style="color: #000000;">state</span><span style="color: #0000FF;">[</span><span style="color: #000000;">MAX</span><span style="color: #0000FF;">][</span><span style="color: #000000;">k</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">-</span> <span style="color: #000000;">state</span><span style="color: #0000FF;">[</span><span style="color: #000000;">MIN</span><span style="color: #0000FF;">][</span><span style="color: #000000;">k</span><span style="color: #0000FF;">])</span> <span style="color: #0000FF;">*</span> <span style="color: #7060A8;">rnd</span><span style="color: #0000FF;">()</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">iter</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">1</span> <span style="color: #0000FF;">+</span> <span style="color: #000000;">state</span><span style="color: #0000FF;">[</span><span style="color: #000000;">ITER</span><span style="color: #0000FF;">]</span>
<span style="color: #008080;">return</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">iter</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">gbpos</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">gbval</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">state</span><span style="color: #0000FF;">[</span><span style="color: #000000;">MIN</span><span style="color: #0000FF;">],</span> <span style="color: #000000;">state</span><span style="color: #0000FF;">[</span><span style="color: #000000;">MAX</span><span style="color: #0000FF;">],</span> <span style="color: #000000;">state</span><span style="color: #0000FF;">[</span><span style="color: #000000;">PARAMS</span><span style="color: #0000FF;">],</span>
<span style="color: #000000;">pos</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">vel</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">bpos</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">bval</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">particles</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">dims</span><span style="color: #0000FF;">}</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
<span style="color: #008080;">function</span> <span style="color: #000000;">iterate</span><span style="color: #0000FF;">(</span><span style="color: #004080;">integer</span> <span style="color: #000000;">fn</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">n</span><span style="color: #0000FF;">,</span> <span style="color: #004080;">sequence</span> <span style="color: #000000;">state</span><span style="color: #0000FF;">)</span>
<span style="color: #004080;">sequence</span> <span style="color: #000000;">r</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">state</span><span style="color: #0000FF;">,</span>
<span style="color: #000000;">old</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">state</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">n</span><span style="color: #0000FF;">=-</span><span style="color: #000000;">1</span> <span style="color: #008080;">then</span>
<span style="color: #008080;">while</span> <span style="color: #004600;">true</span> <span style="color: #008080;">do</span>
<span style="color: #000000;">r</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">pso</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">r</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">if</span> <span style="color: #0000FF;">(</span><span style="color: #000000;">r</span> <span style="color: #0000FF;">==</span> <span style="color: #000000;">old</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">then</span> <span style="color: #008080;">exit</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #000000;">old</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">r</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">while</span>
<span style="color: #008080;">else</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">n</span> <span style="color: #008080;">do</span>
<span style="color: #000000;">r</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">pso</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">r</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">return</span> <span style="color: #000000;">r</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
<span style="color: #008080;">function</span> <span style="color: #000000;">mccormick</span><span style="color: #0000FF;">(</span><span style="color: #004080;">sequence</span> <span style="color: #000000;">x</span><span style="color: #0000FF;">)</span>
<span style="color: #004080;">atom</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">a</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">b</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">x</span>
<span style="color: #008080;">return</span> <span style="color: #7060A8;">sin</span><span style="color: #0000FF;">(</span><span style="color: #000000;">a</span> <span style="color: #0000FF;">+</span> <span style="color: #000000;">b</span><span style="color: #0000FF;">)</span> <span style="color: #0000FF;">+</span> <span style="color: #0000FF;">(</span><span style="color: #000000;">a</span> <span style="color: #0000FF;">-</span> <span style="color: #000000;">b</span><span style="color: #0000FF;">)</span> <span style="color: #0000FF;">*</span> <span style="color: #0000FF;">(</span><span style="color: #000000;">a</span> <span style="color: #0000FF;">-</span> <span style="color: #000000;">b</span><span style="color: #0000FF;">)</span> <span style="color: #0000FF;">+</span> <span style="color: #000000;">1.0</span> <span style="color: #0000FF;">+</span> <span style="color: #000000;">2.5</span> <span style="color: #0000FF;">*</span> <span style="color: #000000;">b</span> <span style="color: #0000FF;">-</span> <span style="color: #000000;">1.5</span> <span style="color: #0000FF;">*</span> <span style="color: #000000;">a</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
<span style="color: #008080;">function</span> <span style="color: #000000;">michalewicz</span><span style="color: #0000FF;">(</span><span style="color: #004080;">sequence</span> <span style="color: #000000;">x</span><span style="color: #0000FF;">)</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">m</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">10</span><span style="color: #0000FF;">,</span>
<span style="color: #000000;">d</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">x</span><span style="color: #0000FF;">)</span>
<span style="color: #004080;">atom</span> <span style="color: #000000;">total</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0.0</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">d</span> <span style="color: #008080;">do</span>
<span style="color: #004080;">atom</span> <span style="color: #000000;">j</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">x</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">],</span>
<span style="color: #000000;">k</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">sin</span><span style="color: #0000FF;">(</span><span style="color: #000000;">i</span> <span style="color: #0000FF;">*</span> <span style="color: #000000;">j</span> <span style="color: #0000FF;">*</span> <span style="color: #000000;">j</span> <span style="color: #0000FF;">/</span> <span style="color: #004600;">PI</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">total</span> <span style="color: #0000FF;">+=</span> <span style="color: #7060A8;">sin</span><span style="color: #0000FF;">(</span><span style="color: #000000;">j</span><span style="color: #0000FF;">)</span> <span style="color: #0000FF;">*</span> <span style="color: #7060A8;">power</span><span style="color: #0000FF;">(</span><span style="color: #000000;">k</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">2.0</span> <span style="color: #0000FF;">*</span> <span style="color: #000000;">m</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<span style="color: #008080;">return</span> <span style="color: #0000FF;">-</span><span style="color: #000000;">total</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
<span style="color: #008080;">procedure</span> <span style="color: #000000;">main</span><span style="color: #0000FF;">()</span>
<span style="color: #004080;">sequence</span> <span style="color: #000000;">mins</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{-</span><span style="color: #000000;">1.5</span><span style="color: #0000FF;">,</span> <span style="color: #0000FF;">-</span><span style="color: #000000;">3.0</span><span style="color: #0000FF;">},</span>
<span style="color: #000000;">maxs</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">4.0</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">4.0</span><span style="color: #0000FF;">},</span>
<span style="color: #000000;">params</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">0.0</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">0.6</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">0.3</span><span style="color: #0000FF;">}</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">nParticles</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">100</span>
<span style="color: #004080;">sequence</span> <span style="color: #000000;">state</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">psoInit</span><span style="color: #0000FF;">(</span><span style="color: #000000;">mins</span><span style="color: #0000FF;">,</span><span style="color: #000000;">maxs</span><span style="color: #0000FF;">,</span><span style="color: #000000;">params</span><span style="color: #0000FF;">,</span><span style="color: #000000;">nParticles</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">state</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">iterate</span><span style="color: #0000FF;">(</span><span style="color: #000000;">mccormick</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">40</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">state</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">report</span><span style="color: #0000FF;">(</span><span style="color: #000000;">state</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"McCormick"</span><span style="color: #0000FF;">)</span>
<span style="color: #004080;">atom</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">x</span><span style="color: #0000FF;">,</span><span style="color: #000000;">y</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">state</span><span style="color: #0000FF;">[</span><span style="color: #000000;">GBPOS</span><span style="color: #0000FF;">]</span>
<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"f(%.4f, %.4f) : %f\n\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">x</span><span style="color: #0000FF;">,</span><span style="color: #000000;">y</span><span style="color: #0000FF;">,</span><span style="color: #000000;">mccormick</span><span style="color: #0000FF;">({</span><span style="color: #000000;">x</span><span style="color: #0000FF;">,</span><span style="color: #000000;">y</span><span style="color: #0000FF;">})})</span>
<span style="color: #000000;">mins</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">0.0</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">0.0</span><span style="color: #0000FF;">}</span>
<span style="color: #000000;">maxs</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #004600;">PI</span><span style="color: #0000FF;">,</span> <span style="color: #004600;">PI</span><span style="color: #0000FF;">}</span>
<span style="color: #000000;">params</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">0.3</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">0.3</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">0.3</span><span style="color: #0000FF;">}</span>
<span style="color: #000000;">nParticles</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">1000</span>
<span style="color: #000000;">state</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">psoInit</span><span style="color: #0000FF;">(</span><span style="color: #000000;">mins</span><span style="color: #0000FF;">,</span><span style="color: #000000;">maxs</span><span style="color: #0000FF;">,</span><span style="color: #000000;">params</span><span style="color: #0000FF;">,</span><span style="color: #000000;">nParticles</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">state</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">iterate</span><span style="color: #0000FF;">(</span><span style="color: #000000;">michalewicz</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">30</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">state</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">report</span><span style="color: #0000FF;">(</span><span style="color: #000000;">state</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"Michalewicz (2D)"</span><span style="color: #0000FF;">)</span>
<span style="color: #0000FF;">{</span><span style="color: #000000;">x</span><span style="color: #0000FF;">,</span><span style="color: #000000;">y</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">state</span><span style="color: #0000FF;">[</span><span style="color: #000000;">GBPOS</span><span style="color: #0000FF;">]</span>
<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"f(%.5f, %.5f) : %f\n\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">x</span><span style="color: #0000FF;">,</span><span style="color: #000000;">y</span><span style="color: #0000FF;">,</span><span style="color: #000000;">michalewicz</span><span style="color: #0000FF;">({</span><span style="color: #000000;">x</span><span style="color: #0000FF;">,</span><span style="color: #000000;">y</span><span style="color: #0000FF;">})})</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">procedure</span>
<span style="color: #000000;">main</span><span style="color: #0000FF;">()</span>
<!--</syntaxhighlight>-->
{{out}}
<pre>
Line 1,765 ⟶ 2,045:
=={{header|Python}}==
{{trans|D}}
<langsyntaxhighlight lang="python">import math
import random
 
Line 1,896 ⟶ 2,176:
print "f(2.20, 1.57) : %.16f" % (michalewicz([2.2, 1.57]))
 
main()</langsyntaxhighlight>
{{out}}
<pre>Test Function : McCormick
Line 1,911 ⟶ 2,191:
 
=={{header|Racket}}==
<langsyntaxhighlight lang="racket">#lang racket/base
(require racket/list racket/math)
 
Line 1,989 ⟶ 2,269:
(PSO (Michalewitz 5) 1000 30 (box 0) (box pi) #:ω 0.3 #:φ_p 0.3 #:φ_g 0.3 #:> <)
(displayln "Michalewitz 10d [-9.66015]")
(PSO (Michalewitz 10) 1000 30 (box 0) (box pi) #:ω 0.3 #:φ_p 0.3 #:φ_g 0.3 #:> <)</langsyntaxhighlight>
{{out}}
 
Line 2,021 ⟶ 2,301:
1.8558804696523914)
-6.432092623300999</pre>
 
=={{header|Raku}}==
(formerly Perl 6)
{{trans|J (via Javascript, Kotlin, D, Python)}}
<syntaxhighlight lang="raku" line>sub pso-init (%y) {
my $d = @(%y{'min'});
my $n = %y{'n'};
 
%y{'gbval'} = Inf;
%y{'gbpos'} = [Inf xx $d];
%y{'bval'} = [Inf xx $n];
%y{'bpos'} = [%y{'min'} xx $n];
%y{'pos'} = [%y{'min'} xx $n];
%y{'vel'} = [[0 xx $d] xx $n];
 
%y;
}
 
sub pso (&fn, %y) {
my %p = %y{'p'};
my $n = %y{'n'};
my $d = @(%y{'min'});
my @bpos = %y{'min'} xx $n;
my $gbval = Inf;
my $rand-g = rand;
my (@pos, @vel, @v, @gbpos, @bval);
 
for 0 ..^ $n -> \j {
@v[j] = &fn(%y{'pos'}[j]); # evaluate
 
# update
if @v[j] < %y{'bval'}[j] {
@bpos[j] = %y{'pos'}[j];
@bval[j] = @v[j];
} else {
@bpos[j] = %y{'bpos'}[j];
@bval[j] = %y{'bval'}[j];
}
if @bval[j] < $gbval {
$gbval = @bval[j];
@gbpos = |@bpos[j];
}
}
 
# migrate
for 0 ..^ $n -> \j {
my $rand-p = rand;
my $ok = True;
for 0 ..^ $d -> \k {
@vel[j;k] = %p{'ω'} × %y{'vel'}[j;k]
+ %p{'φ-p'} × $rand-p × (@bpos[j;k] - %y{'pos'}[j;k])
+ %p{'φ-g'} × $rand-g × (@gbpos[k] - %y{'pos'}[j;k]);
@pos[j;k] = %y{'pos'}[j;k] + @vel[j;k];
$ok = %y{'min'}[k] < @pos[j;k] < %y{'max'}[k] if $ok;
}
next if $ok;
@pos[j;$_] = %y{'min'}[$_] + (%y{'max'}[$_] - %y{'min'}[$_]) × rand for 0 ..^ $d;
}
 
return {gbpos => @gbpos, gbval => $gbval, bpos => @bpos, bval => @bval, pos => @pos, vel => @vel,
min => %y{'min'}, max => %y{'max'}, p=> %y{'p'}, n => $n}
}
 
sub report ($function-name, %state) {
say $function-name;
say '🌐 best position: ' ~ %state{'gbpos'}.fmt('%.5f');
say '🌐 best value: ' ~ %state{'gbval'}.fmt('%.5f');
say '';
}
 
sub mccormick (@x) {
my ($a,$b) = @x;
sin($a+$b) + ($a-$b)**2 + (1 + 2.5×$b - 1.5×$a)
}
 
my %state = pso-init( {
min => [-1.5, -3],
max => [4, 4],
n => 100,
p => {ω=> 0, φ-p=> 0.6, φ-g=> 0.3},
} );
%state = pso(&mccormick, %state) for 1 .. 40;
report 'McCormick', %state;
 
sub michalewicz (@x) {
my $sum;
my $m = 10;
for 1..@x -> $i {
my $j = @x[$i-1];
my $k = sin($i × $j**2/π);
$sum += sin($j) × $k**(2×$m)
}
-$sum
}
 
%state = pso-init( {
min => [0, 0],
max => [π, π],
n => 1000,
p => {ω=> 0.3, φ-p=> 0.3, φ-g=> 0.3},
} );
%state = pso(&michalewicz, %state) for 1 .. 30;
report 'Michalewicz', %state;</syntaxhighlight>
{{out}}
<pre>McCormick
🌐 best position: -0.54714 -1.54710
🌐 best value: -1.91322
 
Michalewicz
🌐 best position: 2.20291 1.57080
🌐 best value: -1.80130</pre>
 
=={{header|REXX}}==
Line 2,037 ⟶ 2,428:
 
Note that REXX uses decimal floating point, not binary.
<langsyntaxhighlight lang="rexx">/*REXX program calculates Particle Swarm Optimization as it migrates through a solution.*/
numeric digits length( pi() ) - 1 length(.) /*use the number of decimal digs in pi.*/
parse arg x y d #part sDigs . /*obtain optional arguments from the CL*/
if x=='' | x=="," then x= -0.5 /*Not specified? Then use the default.*/
Line 2,049 ⟶ 2,440:
show= sDigs + 3 /*adjust number decimal digits for show*/
say "══iteration══" center('X',show,"═") center('Y',show,"═") center('D',show,"═")
#= 0; call refine x, y /*the#: number ofREFINE iterations; for invoke REFINE. */
call refine x,y /* [↓] same as ÷ by five.*/
do until refine(minX, minY) /*perform until the mix is "refined". */
d=d * .2 /*decrease the difference in the mix. .*/
end /*until*/ /* [↑] stop refining if no difference.*/
$= 15 + show*2; say /*compute the indentation for alignment*/
say
$= 15 + show * 2 /*compute the indentation for alignment*/
say right('The global minimum for f(-.54719, -1.54719) ───► ', $) fmt(f(-.54719, -1.54719))
say right('The published global minimum is:' , $) fmt( -1.9133 )
exit /*stick a fork in it, we're all done. */
/*──────────────────────────────────────────────────────────────────────────────────────*/
refine: parse arg xx,yy; h= d * .5 /*compute ½ distance. */
do x=xx-d to xx+d by h
do y=yy-d to yy+d by h; f= f(x, y); if f>=minF then iterate
new= fmt(x) fmt(y) fmt(f); if new=old then return 1
#= # + 1; say center(#,13) new /*bump #iter.; iterations.show new*/
say center(#,13) new minF= f; minX= x; minY= y; old= new /*show " " assign new values. */
minF= f; minX= x; minY= y; old= new /*assign new values. */
end /*y*/
end /*x*/
Line 2,072 ⟶ 2,460:
/*──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────*/
f: procedure: parse arg a,b; return sin(a+b) + (a-b)**2 - 1.5*a + 2.5*b + 1
fmt: ?= format(arg(1), , sDigs); L= length(?); if pos(., ?)\==0 then ?= strip( strip(?, 'T', 0), "T", .); return left(?, L)
pi: pi=3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679821480865; return pi
r2r: return arg(1) // ( pi() * 2) /*normalize radians ───► a unit circle.*/
sin: procedure; arg x; x= r2r(x); z= x; xx= x*x; do k=2 by 2 until p=z; p=z; x= -x* xx/ (k*(k+1)); z= z+x; end; return z</langsyntaxhighlight>
{{out|output|text=&nbsp; when using the default input:}}
<pre>
Line 2,143 ⟶ 2,531:
Output note: &nbsp; the published global minimum (referenced above, as well as the function's arguments) can be found at:
::::: &nbsp; <u>[http://www.sfu.ca/~ssurjano/mccorm.html http://www.sfu.ca/~ssurjano/mccorm.html]</u>
 
<br><br>
=={{header|Wren}}==
{{trans|Kotlin}}
{{libheader|Wren-dynamic}}
<syntaxhighlight lang="wren">import "random" for Random
import "./dynamic" for Tuple
 
var Parameters = Tuple.create("Parameters", ["omega", "phip", "phig"])
 
var fields = [
"iter", "gbpos", "gbval", "min", "max", "parameters",
"pos", "vel", "bpos", "bval", "nParticles", "nDims"
]
 
var State = Tuple.create("State", fields)
 
var report = Fn.new { |state, testfunc|
System.print("Test Function : %(testfunc)")
System.print("Iterations : %(state.iter)")
System.print("Global Best Position : %(state.gbpos)")
System.print("Global Best Value : %(state.gbval)")
}
 
var psoInit = Fn.new { |min, max, parameters, nParticles|
var nDims = min.count
var pos = List.filled(nParticles, null)
var vel = List.filled(nParticles, null)
var bpos = List.filled(nParticles, null)
var bval = List.filled(nParticles, 1/0)
for (i in 0...nParticles) {
pos[i] = min.toList
vel[i] = List.filled(nDims, 0)
bpos[i] = min.toList
}
var iter = 0
var gbpos = List.filled(nDims, 1/0 )
var gbval = 1/0
return State.new(iter, gbpos, gbval, min, max, parameters,
pos, vel, bpos, bval, nParticles, nDims)
}
 
var r = Random.new()
 
var pso = Fn.new { |fn, y|
var p = y.parameters
var v = List.filled(y.nParticles, 0)
var bpos = List.filled(y.nParticles, null)
for (i in 0...y.nParticles) bpos[i] = y.min.toList
var bval = List.filled(y.nParticles, 0)
var gbpos = List.filled(y.nDims, 0)
var gbval = 1/0
for (j in 0...y.nParticles) {
// evaluate
v[j] = fn.call(y.pos[j])
// update
if (v[j] < y.bval[j]) {
bpos[j] = y.pos[j]
bval[j] = v[j]
} else {
bpos[j] = y.bpos[j]
bval[j] = y.bval[j]
}
if (bval[j] < gbval) {
gbval = bval[j]
gbpos = bpos[j]
}
}
var rg = r.float()
var pos = List.filled(y.nParticles, null)
var vel = List.filled(y.nParticles, null)
for (i in 0...y.nParticles) {
pos[i] = List.filled(y.nDims, 0)
vel[i] = List.filled(y.nDims, 0)
}
for (j in 0...y.nParticles) {
// migrate
var rp = r.float()
var ok = true
for (k in 0...y.nDims) {
vel[j][k] = p.omega * y.vel[j][k] +
p.phip * rp * (bpos[j][k] - y.pos[j][k]) +
p.phig * rg * (gbpos[k] - y.pos[j][k])
pos[j][k] = y.pos[j][k] + vel[j][k]
ok = ok && y.min[k] < pos[j][k] && y.max[k] > pos[j][k]
}
if (!ok) {
for (k in 0...y.nDims) {
pos[j][k]= y.min[k] + (y.max[k] - y.min[k]) * r.float()
}
}
}
var iter = 1 + y.iter
return State.new(
iter, gbpos, gbval, y.min, y.max, y.parameters,
pos, vel, bpos, bval, y.nParticles, y.nDims
)
}
 
var iterate = Fn.new { |fn, n, y|
var r = y
var old = y
if (n == 2147483647) {
while (true) {
r = pso.call(fn, r)
if (r == old) break
old = r
}
} else {
for (i in 1..n) r = pso.call(fn, r)
}
return r
}
 
var mccormick = Fn.new { |x|
var a = x[0]
var b = x[1]
return (a + b).sin + (a - b) * (a - b) + 1 + 2.5 * b - 1.5 * a
}
 
var michalewicz = Fn.new { |x|
var m = 10
var d = x.count
var sum = 0
for (i in 1..d) {
var j = x[i - 1]
var k = (i * j * j / Num.pi).sin
sum = sum + j.sin * k.pow(2 * m)
}
return -sum
}
 
var state = psoInit.call([-1.5, -3], [4, 4], Parameters.new(0, 0.6, 0.3), 100)
state = iterate.call(mccormick, 40, state)
report.call(state, "McCormick")
System.print("f(-0.54719, -1.54719) : %(mccormick.call([-0.54719, -1.54719]))")
System.print()
state = psoInit.call([0, 0], [Num.pi, Num.pi], Parameters.new(0.3, 0.3, 0.3), 1000)
state = iterate.call(michalewicz, 30, state)
report.call(state, "Michalewicz (2D)")
System.print("f(2.20, 1.57) : %(michalewicz.call([2.2, 1.57]))")</syntaxhighlight>
 
{{out}}
Sample run:
<pre>
Test Function : McCormick
Iterations : 40
Global Best Position : [-0.54763537556709, -1.5469760587453]
Global Best Value : -1.9132225000184
f(-0.54719, -1.54719) : -1.9132229548823
 
Test Function : Michalewicz (2D)
Iterations : 30
Global Best Position : [2.2029075565418, 1.570796180786]
Global Best Value : -1.8013034100303
f(2.20, 1.57) : -1.8011407184738
</pre>
PureFox
9,476

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