/// <summary>
/// For activation functions that accept auxiliary arguments; generates random initial values for aux arguments for newly
/// added nodes (from an 'add neuron' mutation).
/// </summary>
public double[] GetRandomAuxArgs(XorShiftRandom rng, double connectionWeightRange)
{
double[] auxArgs = new double[2];
auxArgs[0] = (rng.NextDouble() - 0.5) * 2.0;
auxArgs[1] = rng.NextDouble();
return(auxArgs);
}
/// <summary>
/// Initialise agent and prey positions. The prey is positioned randomly with at least 4 empty squares between it and a wall (in all directions).
/// The agent is positioned randomly but such that the prey is within sensor range (distance 2 or less).
/// </summary>
public void InitPositions()
{
// Random pos at least 4 units away from any wall.
_preyPos._x = 4 + _rng.Next(_gridSize - 8);
_preyPos._y = 4 + _rng.Next(_gridSize - 8);
// Agent position. Within range of the prey.
double t = 2.0 * Math.PI * _rng.NextDouble(); // Random angle.
double r = 2.0 + _rng.NextDouble() * 2.0; // Distance between 2 and 4.
_agentPos._x = _preyPos._x + (int)Math.Floor(Math.Cos(t) * r);
_agentPos._y = _preyPos._y + (int)Math.Floor(Math.Sin(t) * r);
}
public void NextDouble10M()
{
for (int i = 0; i < __loops; i++)
{
_rng.NextDouble();
}
}
public void TestProbabilisticRound()
{
var rng = new XorShiftRandom(0);
for (int i = 0; i < 1000000; i++)
{
double valReal = 100 * rng.NextDouble();
double valRound = NumericsUtils.ProbabilisticRound(valReal, rng);
Assert.IsTrue(valRound == Math.Floor(valReal) || valRound == Math.Ceiling(valReal));
}
}
public void NextDouble()
{
int sampleCount = 10000000;
XorShiftRandom rng = new XorShiftRandom();
double[] sampleArr = new double[sampleCount];
for (int i = 0; i < sampleCount; i++)
{
sampleArr[i] = rng.NextDouble();
}
UniformDistributionTest(sampleArr, 0.0, 1.0);
}
private void PerformMutationOp_Position()
{
int oldPos = (int)_strmA.Position;
int newPos = (int)(_rng.NextDouble() * 1.02 * _strmA.Position);
_strmA.Position = newPos;
_strmB.Position = newPos;
Debug.WriteLine(string.Format("Position = {0} (was {1})", newPos, oldPos));
}
/// <summary>
/// Take a sample from the standard gaussian distribution, i.e. with mean of 0 and standard deviation of 1.
/// </summary>
public double SampleStandard()
{
for (; ;)
{
// Select box at random.
byte u = _rng.NextByte();
int i = (int)(u & 0x7F);
double sign = ((u & 0x80) == 0) ? -1.0 : 1.0;
// Generate uniform random value with range [0,0xffffffff].
uint u2 = _rng.NextUInt();
// Special case for the base segment.
if (0 == i)
{
if (u2 < _xComp[0])
{ // Generated x is within R0.
return(u2 * __UIntToU * _A_Div_Y0 * sign);
}
// Generated x is in the tail of the distribution.
return(SampleTail() * sign);
}
// All other segments.
if (u2 < _xComp[i])
{ // Generated x is within the rectangle.
return(u2 * __UIntToU * _x[i] * sign);
}
// Generated x is outside of the rectangle.
// Generate a random y coordinate and test if our (x,y) is within the distribution curve.
// This execution path is relatively slow/expensive (makes a call to Math.Exp()) but relatively rarely executed,
// although more often than the 'tail' path (above).
double x = u2 * __UIntToU * _x[i];
if (_y[i - 1] + ((_y[i] - _y[i - 1]) * _rng.NextDouble()) < GaussianPdfDenorm(x))
{
return(x * sign);
}
}
}
/// <summary>
/// Add objects to the Box2d world.
/// </summary>
protected override void PopulateWorld()
{
// ==== Define the ground body ====
BodyDef groundBodyDef = new BodyDef();
groundBodyDef.Position.Set(_trackLengthHalf, -1f);
// Call the body factory which creates the ground box shape.
// The body is also added to the world.
Body groundBody = _world.CreateBody(groundBodyDef);
// Define the ground box shape.
PolygonDef groundShapeDef = new PolygonDef();
// The extents are the half-widths of the box.
groundShapeDef.SetAsBox(_trackLengthHalf + 1f, 1f);
groundShapeDef.Friction = _simParams._defaultFriction;
groundShapeDef.Restitution = _simParams._defaultRestitution;
groundShapeDef.Filter.CategoryBits = 0x3;
// Add the ground shape to the ground body.
groundBody.CreateShape(groundShapeDef);
// Add some small mounds/bumps to the ground.
for (float x = -1f; x < 40f; x += 0.3f + ((float)_rng.NextDouble() * 0.2f))
{
WalkerWorldUtils.CreateMound(_world, x, 0f, _simParams._defaultFriction, _simParams._defaultRestitution);
}
// ==== Define walker torso.
float walkerX = 0f;
float walkerY = 1.55f;// + ((float)_rng.NextDouble() * 0.1f);
BodyDef torsoBodyDef = new BodyDef();
torsoBodyDef.Position.Set(walkerX, walkerY);
torsoBodyDef.IsBullet = true;
// Create walker torso.
_torsoBody = _world.CreateBody(torsoBodyDef);
PolygonDef torsoShapeDef = new PolygonDef();
torsoShapeDef.SetAsBox(0.10f, 0.45f);
torsoShapeDef.Friction = _simParams._defaultFriction;
torsoShapeDef.Restitution = 0f;
torsoShapeDef.Density = 2f;
torsoShapeDef.Filter.CategoryBits = 0x2;
_torsoBody.CreateShape(torsoShapeDef);
_torsoBody.SetMassFromShapes();
// ===== Create legs.
// Leg joint definition.
RevoluteJointDef jointDef = new RevoluteJointDef();
jointDef.CollideConnected = false;
jointDef.EnableMotor = true;
jointDef.MaxMotorTorque = 0f;
// Other re-usable stuff .
const float legRadius = 0.05f; // Half the thickness of the leg
Vec2 upperLegPosBase = new Vec2(walkerX, walkerY - 0.4f);
Vec2 lowerLegPosBase = new Vec2(walkerX, walkerY - 0.9f);
// ===== Create left leg.
// Upper leg.
Body upperLeftLegBody = CreatePole(upperLegPosBase, 0.5f, (float)SysMath.PI, legRadius, 2f, 0x1);
// Join to torso (hip joint)
jointDef.Initialize(_torsoBody, upperLeftLegBody, upperLegPosBase);
_leftHipJoint = (RevoluteJoint)_world.CreateJoint(jointDef);
// Lower leg.
_leftLowerLegBody = CreatePole(lowerLegPosBase, __lowerLegLength, (float)SysMath.PI, legRadius, 2f, 0x1);
// Join to upper leg (knee joint)
jointDef.Initialize(upperLeftLegBody, _leftLowerLegBody, lowerLegPosBase);
_leftKneeJoint = (RevoluteJoint)_world.CreateJoint(jointDef);
// ===== Create right leg.
// Upper leg.
Body upperRightLegBody = CreatePole(upperLegPosBase, 0.5f, (float)SysMath.PI, legRadius, 2f, 0x1);
// Join to torso (hip joint)
jointDef.Initialize(_torsoBody, upperRightLegBody, upperLegPosBase);
_rightHipJoint = (RevoluteJoint)_world.CreateJoint(jointDef);
// Lower leg.
_rightLowerLegBody = CreatePole(lowerLegPosBase, __lowerLegLength, (float)SysMath.PI, legRadius, 2f, 0x1);
// Join to upper leg (knee joint)
jointDef.Initialize(upperRightLegBody, _rightLowerLegBody, lowerLegPosBase);
_rightKneeJoint = (RevoluteJoint)_world.CreateJoint(jointDef);
}