public double[] GetAveragePotentials()
{
int n = posParticles.Length;
double pSum = 0.0;
double pSum2 = 0.0;
double charge = 1.0 / n; // Total one Coulomb on each surface.
foreach (Vector x in posParticles)
{
double phi = EField.GetPotential(x, posParticles, negParticles, charge);
pSum += phi;
pSum2 += phi * phi;
}
double nSum = 0.0;
double nSum2 = 0.0;
foreach (Vector x in negParticles)
{
double phi = EField.GetPotential(x, posParticles, negParticles, charge);
nSum += phi;
nSum2 += phi * phi;
}
double pAvg = pSum / n;
double pVar = (pSum2 - n * pAvg * pAvg) / (n - 1);
double pSdev = Math.Sqrt(pVar);
double nAvg = nSum / n;
double nVar = (nSum2 - n * nAvg * nAvg) / (n - 1);
double nSdev = Math.Sqrt(nVar);
return(new double[] { pAvg, pSdev, nAvg, nSdev });
}
public void DoSteps(int nSteps)
{
int n = posParticles.Length;
double charge = 1.0 / n; // Total one Coulomb on each surface.
for (int iStep = 0; iStep < nSteps; iStep++)
{
// All the positive particles.
for (int i = 0; i < n; i++)
{
Vector x0 = posParticles[i];
double phi0 = EField.GetPotential(x0, posParticles, negParticles, charge);
Vector x1 = anode.RandomPoint();
posParticles[i] = x1;
double phi1 = EField.GetPotential(x1, posParticles, negParticles, charge);
// Put back the old position if the energy is not lowered.
if (phi1 > phi0)
{
posParticles[i] = x0;
}
}
// All the negative particles.
for (int i = 0; i < n; i++)
{
Vector x0 = negParticles[i];
double phi0 = EField.GetPotential(x0, posParticles, negParticles, charge);
Vector x1 = cathode.RandomPoint();
negParticles[i] = x1;
double phi1 = EField.GetPotential(x1, posParticles, negParticles, charge);
// Put back the old position if the energy is not lowered. (I.e. moved toward zero.)
if (phi1 < phi0)
{
negParticles[i] = x0;
}
}
}
}
static void Main(string[] args)
{
if (!ReadArgs(args))
{
return;
}
try
{
if (outFile != null)
{
tw = new StreamWriter(outFile);
}
//WriteLine("Command line: efield {0}", String.Join(" ", args));
WriteLine("Command line: {0}", Environment.CommandLine);
WriteLine("Run by: {0}\\{1} on {2}", Environment.UserDomainName, Environment.UserName, Environment.MachineName);
DateTime startTime = DateTime.Now;
WriteLine(startTime.ToString());
if (!haveSeed)
{
seed = (uint)startTime.Ticks;
}
PseudoDES rand = new PseudoDES(0, seed);
WriteLine("Seed = {0}", seed);
if (!File.Exists(posFileName))
{
throw new Exception(string.Format("Anode description file {0} not found", posFileName));
}
if (!File.Exists(negFileName))
{
throw new Exception(string.Format("Cathode description file {0} not found", negFileName));
}
Surface anode = new Surface(new StlFile(posFileName), rand);
Surface cathode = new Surface(new StlFile(negFileName), rand);
WriteLine("Anode: {0} Triangles: {1} Area: {2:0.0000} m^2", posFileName, anode.TriangleCount, anode.TotalArea);
WriteLine("Cathode: {0} Triangles: {1} Area: {2:0.0000} m^2", negFileName, cathode.TriangleCount, cathode.TotalArea);
// Trap ^C
Console.CancelKeyPress += new ConsoleCancelEventHandler(Console_CancelKeyPress);
// Create the Balancer.
Balancer baal = new Balancer(nParticles, anode, cathode);
// Let's see the starting potentials.
double[] pots = baal.GetAveragePotentials();
WriteLine("Steps: {0,5} Potentials: {1:0.00e00} {2:0.00e00} {3:0.00e00} {4:0.00e00}", 0, pots[0], pots[1], pots[2], pots[3]);
int batch = 10;
for (int nDone = 0; nDone < nReps; nDone += batch)
{
// Run some steps.
baal.DoSteps(Math.Min(batch, nReps - nDone));
// And report.
pots = baal.GetAveragePotentials();
WriteLine("Steps: {0,5} Potentials: {1:0.00e00} {2:0.00e00} {3:0.00e00} {4:0.00e00}",
Math.Min(nDone + batch, nReps), pots[0], pots[1], pots[2], pots[3]);
if (cancelWasReceived)
{
break;
}
}
DateTime endTime = DateTime.Now;
TimeSpan runTime = endTime - startTime;
if (cancelWasReceived)
{
WriteLine("Received ^C, terminating early!");
}
WriteLine("Run time = {0:0.000} minutes", runTime.TotalMinutes);
double potentialDifference = pots[0] - pots[2];
double posSdev = 100.0 * pots[1] / Math.Abs(pots[0]);
double negSdev = 100.0 * pots[3] / Math.Abs(pots[2]);
double capacitance = 1e12 / potentialDifference; // in picoFarads
WriteLine("Final potentials: {0:0.00e00} ({1:0.0}%) {2:0.00e00} ({3:0.0}%)", pots[0], posSdev, pots[2], negSdev);
WriteLine("Final potential difference: {0:0.00e00}", potentialDifference);
WriteLine("Capacitance: {0:0.0} pF", capacitance);
// If writing to a file, dump the final particle positions
if (tw != null)
{
if (xN > 0)
{
double step = (x1 - x0) / xN;
double charge = 1.0 / baal.posParticles.Length;
tw.WriteLine("Scan along X-axis");
for (int i = 0; i <= xN; i++)
{
double x = x0 + i * step; // x in mm
double phi = EField.GetPotential(new Vector(x * 0.001, 0.0, 0.0), baal.posParticles, baal.posParticles, charge);
tw.WriteLine("{0,10:0.00} {1:0.000e00}", x, phi);
}
}
int n = baal.posParticles.Length;
tw.WriteLine("particles {0} {0}", n);
foreach (Vector x in baal.posParticles)
{
tw.WriteLine("{0,10:0.0000}{1,10:0.0000}{2,10:0.0000}", x.x, x.y, x.z);
}
foreach (Vector x in baal.negParticles)
{
tw.WriteLine("{0,10:0.0000}{1,10:0.0000}{2,10:0.0000}", x.x, x.y, x.z);
}
}
}
catch (Exception e)
{
Console.WriteLine("Exception: {0}", e.Message);
}
if (tw != null)
{
tw.Close();
}
}