Ejemplo n.º 1
0
double Gravity::perturb(RNG& rng)
{
	double logH = 0.;

	int which = rng.rand_int(x.size());
	int what = rng.rand_int(6);

	// Remove effect of this particle
	increment(which, -1);

	if(what == 0)
	{
		x[which] += 20.*rng.randh();
		x[which] = mod(x[which] + 10., 20.) - 10.;
	}
	else if(what == 1)
	{
		y[which] += 20.*rng.randh();
		y[which] = mod(y[which] + 10., 20.) - 10.;
	}
	else if(what == 2)
	{
		z[which] += 20.*rng.randh();
		z[which] = mod(z[which] + 10., 20.) - 10.;
	}
	else if(what == 3)
	{
		vx[which] += 20.*rng.randh();
		vx[which] = mod(vx[which] + 10., 20.) - 10.;
	}
	else if(what == 4)
	{
		vy[which] += 20.*rng.randh();
		vy[which] = mod(vy[which] + 10., 20.) - 10.;
	}
	else
	{
		vz[which] += 20.*rng.randh();
		vz[which] = mod(vz[which] + 10., 20.) - 10.;
	}

	if(x[which]*x[which] + y[which]*y[which] + z[which]*z[which] > 100.)
		logH = -1E250;

	if(vx[which]*vx[which] + vy[which]*vy[which] + vz[which]*vz[which] > 100.)
		logH = -1E250;

	increment(which, +1);

	staleness++;
	if(staleness >= 100)
		refresh();

	compute_scalars();
	return logH;
}
Ejemplo n.º 2
0
double Sinusoid::perturb(RNG& rng)
{
    double logH = 0.0;

    if(rng.rand() < 0.5)
    {
        // Perturb one of the three parameters
        int which = rng.rand_int(3);
        if(which == 0)
        {
            A = 1.0 - exp(-A);
            A += rng.randh();
            wrap(A, 0.0, 1.0);
            A = -log(1.0 - A);
        }
        else if(which == 1)
        {
            log10_period += 3.0 * rng.randh();
            wrap(log10_period, log10(1E-3 * t_range), log10(t_range));
        }
        else
        {
            phi += 2 * M_PI * rng.randh();
            wrap(phi, 0.0, 2 * M_PI);
        }
    }
    else
    {
        // Perturb some of the ns.
        if(rng.rand() <= 0.5)
        {
            // Just change one
            int which = rng.rand_int(N);
            logH -= -0.5*pow(n[which], 2);
            n[which] += rng.randh();
            logH += -0.5*pow(n[which], 2);
        }
        else
        {
            // Potentially regenerate many
            int reps = pow(N, rng.rand());
            for(int i=0; i<reps; ++i)
                n[rng.rand_int(N)] = rng.randn();
        }

    }

    assemble();

    return logH;
}
Ejemplo n.º 3
0
double BasicCircular::perturb_hyperparameters(RNG& rng)
{
	double logH = 0.;
	int which = rng.rand_int(3);

	if(which == 0)
	{
		xc += size*rng.randh();
        yc += size*rng.randh();
		xc = DNest4::mod(xc - x_min, x_max - x_min) + x_min;
		yc = DNest4::mod(yc - y_min, y_max - y_min) + y_min;
	}
	else if(which == 1)
	{
		width = log(width);
		width += log(1E3)*rng.randh();
		width = DNest4::mod(width - log(1E-2*size), log(1E3)) + log(1E-2*size);
		width = exp(width);
	}
	else if(which == 2)
	{
		mu = log(mu);
		mu += log(mu_max/mu_min)*rng.randh();
		mu = DNest4::mod(mu - log(mu_min), log(mu_max/mu_min)) + log(mu_min);
		mu = exp(mu);
	}

	return logH;
}
Ejemplo n.º 4
0
double Sinusoid::perturb_parameters(RNG& rng)
{
    double logH = 0.0;

    // Perturb one of the three parameters
    int which = rng.rand_int(3);
    if(which == 0)
    {
        A = log(A);

        logH -= -0.5*pow(A/0.1, 2);
        A += 0.1*rng.randh();
        logH += -0.5*pow(A/0.1, 2);

        A = exp(A);
    }
    else if(which == 1)
    {
        log10_period += rng.randh();
        wrap(log10_period, -1.0, 0.0);
    }
    else
    {
        phi += 2 * M_PI * rng.randh();
        wrap(phi, 0.0, 2 * M_PI);
    }

    return logH;
}
Ejemplo n.º 5
0
double MyConditionalPrior::perturb_hyperparameters(RNG& rng)
{
	double logH = 0.0;

    int which = rng.rand_int(4);

    if(which == 0)
    {
        logH += cauchy.perturb(location_log_period, rng);
    }
    else if(which == 1)
    {
        scale_log_period += 5.0*rng.randh();
        wrap(scale_log_period, 0.0, 5.0);
    }
    else if(which == 2)
    {
        logH += cauchy.perturb(location_log_amplitude, rng);
    }
    else
    {
        scale_log_amplitude += 5.0*rng.randh();
        wrap(scale_log_amplitude, 0.0, 5.0);
    }

	return logH;
}
Ejemplo n.º 6
0
double MyConditionalPrior::perturb_hyperparameters(RNG& rng)
{
	double logH = 0.0;

    int which = rng.rand_int(2);
    if(which == 0)
    {
        Cauchy c;
        A_min = log(A_min);
        logH += c.perturb(A_min, rng);
        A_min = exp(A_min);
    }
    else
    {
        mu += 3.0*rng.randh();
        wrap(mu, 0.0, 3.0);
    }

	return logH;
}
Ejemplo n.º 7
0
double Pareto::perturb_hyperparameters(RNG& rng)
{
	double logH = 0.;

	int which = rng.rand_int(2);

	if(which == 0)
	{
		f0 = log(f0);
		f0 += log(f0_max/f0_min)*rng.randh();
		f0 = mod(f0 - log(f0_min), log(f0_max/f0_min)) + log(f0_min);
		f0 = exp(f0);
	}
	else
	{
		alpha += 4.*rng.randh();
		alpha = mod(alpha - 1., 4.) + 1.;
	}

	return logH;
}
Ejemplo n.º 8
0
double Sinusoid::perturb(RNG& rng)
{
    double logH = 0.0;

    int proposal_type = 1;//rng.rand_int(4);

    if(proposal_type == 0)
    {
        // Perturb parameters, changing data along with it
        std::vector<double> mu_old = mu;

        logH += perturb_parameters(rng);
        calculate_mu();

        double n;
        for(size_t i=0; i<N; ++i)
        {
            n = (y[i] - mu_old[i]) / sigma;
            y[i] = mu[i] + sigma * n;
        }

        calculate_logl();
    }
    else if(proposal_type == 1)
    {
        // Perturb parameters, keeping data constant
        // (aka Metropolis step of the posterior!)
        logH -= logl;

        logH += perturb_parameters(rng);

        calculate_mu();
        calculate_logl();

        logH += logl;        
    }
    else if(proposal_type == 2)
    {
        // Just change one datum
        int which = rng.rand_int(N);

        logH -= -0.5*pow((y[which] - mu[which])/sigma, 2);
        y[which] += sigma * rng.randh();
        logH += -0.5*pow((y[which] - mu[which])/sigma, 2);

        calculate_logl();
    }
    else
    {
        // Potentially regenerate many of the data points
        int reps = pow(N, rng.rand());
        int which;
        for(int i=0; i<reps; ++i)
        {
            which = rng.rand_int(N);
            y[which] = mu[which] + sigma * rng.randn();
        }

        calculate_logl();
    }

    return logH;
}