private double CalculateDoubleSimpsonWithThreads(DoubleIntegrationInfo integrationInfo,
Func <double, double, double> surfaceFunction,
int n,
int numberOfThreads)
{
var lockObject = new object();
var stepX = GetStep(n, integrationInfo.XStart, integrationInfo.XEnd);
var stepY = GetStep(n, integrationInfo.YStart, integrationInfo.YEnd);
var options = new ParallelOptions {
MaxDegreeOfParallelism = numberOfThreads
};
var totalSum = 0.0;
using (var writer = new StreamWriter("ThreadsInfo/" + numberOfThreads + ".txt"))
{
Parallel.For <double>(0, (long)n, options, () => 0, (i, state, subtotal) =>
{
for (var j = 0; j < n; j++)
{
subtotal +=
surfaceFunction(GetByOffset(2 * (int)i, integrationInfo.XStart, stepX),
GetByOffset(2 * j, integrationInfo.YStart, stepY)) +
surfaceFunction(GetByOffset(2 * (int)i + 2, integrationInfo.XStart, stepX),
GetByOffset(2 * j, integrationInfo.YStart, stepY)) +
surfaceFunction(GetByOffset(2 * (int)i + 2, integrationInfo.XStart, stepX),
GetByOffset(2 * j + 2, integrationInfo.YStart, stepY)) +
surfaceFunction(GetByOffset(2 * (int)i, integrationInfo.XStart, stepX),
GetByOffset(2 * j + 2, integrationInfo.YStart, stepY)) +
4 *
(surfaceFunction(GetByOffset(2 * (int)i + 1, integrationInfo.XStart, stepX),
GetByOffset(2 * j, integrationInfo.YStart, stepY)) +
surfaceFunction(GetByOffset(2 * (int)i + 2, integrationInfo.XStart, stepX),
GetByOffset(2 * j + 1, integrationInfo.YStart, stepY)) +
surfaceFunction(GetByOffset(2 * (int)i + 1, integrationInfo.XStart, stepX),
GetByOffset(2 * j + 2, integrationInfo.YStart, stepY)) +
surfaceFunction(GetByOffset(2 * (int)i, integrationInfo.XStart, stepX),
GetByOffset(2 * j + 1, integrationInfo.YStart, stepY))) +
16 *
surfaceFunction(GetByOffset(2 * (int)i + 1, integrationInfo.XStart, stepX),
GetByOffset(2 * j + 1, integrationInfo.YStart, stepY));
}
return(subtotal);
}, sum =>
{
lock (lockObject)
{
totalSum += sum;
writer.WriteLine(Thread.CurrentThread.ManagedThreadId + " : " + totalSum);
}
});
}
return(stepX * stepY / 9 * totalSum);
}
static void Main(string[] args)
{
string expression = "-2*x^2+(-2*y^2)+(-3*sin(x)*cos(y))";
Surface _surface = new Surface(expression);
var integrationInfo = new DoubleIntegrationInfo
{
XStart = -100,
XEnd = 100,
YStart = -20,
YEnd = 20
};
var numericalIntegration = new NumericalIntegration();
numericalIntegration.CalculateBySimpsonMethod(integrationInfo, _surface.CalculateSurfaceFunction);
}
public IntegrationExtendedInfo CalculateBySimpsonMethod(DoubleIntegrationInfo integrationInfo, Func <double, double, double> surfaceFunction)
{
var n = (int)(((integrationInfo.XEnd - integrationInfo.XStart) + (integrationInfo.YEnd - integrationInfo.YStart)));
//var n = 600;
double result = 0;
var threadsTime = new Dictionary <int, TimeSpan>();
var stopwatch = new Stopwatch();
for (var i = 1; i <= 15; i++)
{
stopwatch.Start();
result = CalculateDoubleSimpsonWithThreads(integrationInfo, surfaceFunction, n, i);
stopwatch.Stop();
threadsTime.Add(i, stopwatch.Elapsed);
stopwatch.Reset();
}
return(new IntegrationExtendedInfo
{
IntegrationResult = result,
ThreadsTime = threadsTime
});
}