/** One Monte Carlo step */
public void doStep() {
qmwalk.doMCS();
phiFrame.clearData();
phiFrame.append(0, qmwalk.xv, qmwalk.phi0);
phiFrame.setMessage(
"E = " + decimalFormat.format(qmwalk.eAccum / qmwalk.mcs) + " N = " + qmwalk.N);
}
/**
* Computes and plots correlation functions
*
* @param tauMax is the maximum time for correlation functions
*/
public void computeCorrelation(int tauMax) {
plotFrame.clearData();
double energyAccumulator = 0, magnetizationAccumulator = 0;
double energySquaredAccumulator = 0, magnetizationSquaredAccumulator = 0;
for (int t = 0; t < numberOfPoints; t++) {
energyAccumulator += energy[t];
magnetizationAccumulator += magnetization[t];
energySquaredAccumulator += energy[t] * energy[t];
magnetizationSquaredAccumulator += magnetization[t] * magnetization[t];
}
double averageEnergySquared = Math.pow(energyAccumulator / numberOfPoints, 2);
double averageMagnetizationSquared = Math.pow(magnetizationAccumulator / numberOfPoints, 2);
// compute normalization factors
double normE = (energySquaredAccumulator / numberOfPoints) - averageEnergySquared;
double normM = (magnetizationSquaredAccumulator / numberOfPoints) - averageMagnetizationSquared;
for (int tau = 1; tau <= tauMax; tau++) {
double c_MAccumulator = 0;
double c_EAccumulator = 0;
int counter = 0;
for (int t = 0; t < numberOfPoints - tau; t++) {
c_MAccumulator += magnetization[t] * magnetization[t + tau];
c_EAccumulator += energy[t] * energy[t + tau];
counter++;
}
// correlation function defined so that c(0) = 1 and c(infinity) -> 0
plotFrame.append(0, tau, ((c_MAccumulator / counter) - averageMagnetizationSquared) / normM);
plotFrame.append(1, tau, ((c_EAccumulator / counter) - averageEnergySquared) / normE);
}
plotFrame.setVisible(true);
}
MeanFieldApp() {
root = new double[3];
plotFrame.setConnected(true);
plotFrame.setMarkerColor(1, Color.RED);
plotFrame.setMarkerColor(0, Color.BLUE);
energyFrame.setMarkerColor(0, Color.BLUE);
energyFrame.setConnected(true);
numberFormat.setMinimumFractionDigits(3);
}
public void plot() {
double x = mxlimit;
while (x < pxlimit) {
plotFrame.append(0, x, mftanh(x));
plotFrame.append(1, x, x);
energyFrame.append(0, x, freeenergy(x));
x += 0.02;
}
plotFrame.render();
}
public static void main(String[] args) {
PlotFrame frame =
new PlotFrame(
"$\\theta$", "$\\Psi$_{$\\theta$}", "Special Characters: $\\alpha$ to $\\Omega$");
String inputStr = "Wave function $\\Psi$_{$\\theta$}";
DrawableTextLine textLine = new DrawableTextLine(inputStr, -8, 0);
frame.addDrawable(textLine);
textLine.setFontSize(22);
textLine.setFontStyle(java.awt.Font.BOLD);
frame.setVisible(true);
frame.setDefaultCloseOperation(javax.swing.JFrame.EXIT_ON_CLOSE);
}
/**
* Calculates the trajectory of a falling particle and plots the position as a function of time.
*/
public void calculate() {
plotFrame.setAutoclear(false); // data not cleared at beginning of each calculation
// gets initial conditions
double y0 = control.getDouble("Initial y");
double v0 = control.getDouble("Initial v");
// sets initial conditions
Particle ball = new FallingParticle(y0, v0);
// gets parameters
ball.dt = control.getDouble("dt");
while (ball.y > 0) {
ball.step();
plotFrame.append(0, ball.t, ball.y);
plotFrame.append(1, ball.t, ball.analyticPosition());
}
}
public void readXMLData() {
energy = new double[0];
magnetization = new double[0];
numberOfPoints = 0;
String filename = "ising_data.xml";
JFileChooser chooser = OSPFrame.getChooser();
int result = chooser.showOpenDialog(null);
if (result == JFileChooser.APPROVE_OPTION) {
filename = chooser.getSelectedFile().getAbsolutePath();
} else {
return;
}
XMLControlElement xmlControl = new XMLControlElement(filename);
if (xmlControl.failedToRead()) {
control.println("failed to read: " + filename);
} else {
// gets the datasets in the xml file
Iterator it = xmlControl.getObjects(Dataset.class, false).iterator();
while (it.hasNext()) {
Dataset dataset = (Dataset) it.next();
if (dataset.getName().equals("magnetization")) {
magnetization = dataset.getYPoints();
}
if (dataset.getName().equals("energy")) {
energy = dataset.getYPoints();
}
}
numberOfPoints = magnetization.length;
control.println("Reading: " + filename);
control.println("Number of points = " + numberOfPoints);
}
calculate();
plotFrame.repaint();
}
/** Calculates the wave function. */
public void calculate() {
schroedinger.xmin = control.getDouble("xmin");
schroedinger.xmax = control.getDouble("xmax");
schroedinger.stepHeight = control.getDouble("step height at x = 0");
schroedinger.numberOfPoints = control.getInt("number of points");
schroedinger.energy = control.getDouble("energy");
schroedinger.initialize();
schroedinger.solve();
frame.append(0, schroedinger.x, schroedinger.phi);
}
public void computeDistribution(PlotFrame data) {
int numberOfBins = 20;
int numberOccupied = 0;
double occupied[] = new double[numberOfBins];
double number[] = new double[numberOfBins];
double binSize = 1.0 / numberOfBins;
int minX = Lx / 3;
int maxX = 2 * minX;
for (int x = minX; x <= maxX; x++) {
for (int y = 0; y < Ly; y++) {
int bin = (int) (numberOfBins * (site[x][y] % 1));
number[bin]++;
if ((site[x][y] > 1) && (site[x][y] < 2)) {
numberOccupied++;
occupied[bin]++;
}
}
}
data.setMessage("Number occupied = " + numberOccupied);
for (int bin = 0; bin < numberOfBins; bin++) {
data.append(0, (bin + 0.5) * binSize, occupied[bin] / number[bin]);
}
}
/** Resets the accumulated data. */
public void resetData() {
qmwalk.resetData();
phiFrame.clearData();
phiFrame.repaint();
}
/** Constructs SchroedingerApp and sets plotting frame parameters. */
public SchroedingerApp() {
frame.setConnected(0, true);
frame.setMarkerShape(0, Dataset.NO_MARKER);
}