private static void innerFFT(double[] x, long Iterations)
{
for (int i = 0; i < Iterations; i++)
{
FFT.transform(x); // forward transform
FFT.inverse(x); // backward transform
}
}
public static double test(double[] data)
{
int length = data.Length;
double[] numArray = new double[length];
Array.Copy((Array)data, 0, (Array)numArray, 0, length);
FFT.transform(data);
FFT.inverse(data);
double num1 = 0.0;
int index = 0;
while (index < length)
{
double num2 = data[index] - numArray[index];
num1 += num2 * num2;
checked { ++index; }
}
return(Math.Sqrt(num1 / (double)length));
}
public static double measureFFT(int N, double mintime, Random R)
{
double[] data = kernel.RandomVector(checked (2 * N), R);
long num1 = 20000;
Stopwatch stopwatch = new Stopwatch();
stopwatch.start();
int num2 = 0;
while ((long)num2 < num1)
{
FFT.transform(data);
FFT.inverse(data);
checked { ++num2; }
}
stopwatch.stop();
if (FFT.test(data) / (double)N > 0.0 / 1.0)
{
return(0.0);
}
return(FFT.num_flops(N) * (double)num1 / stopwatch.read() * 1E-06);
}
// each measurement returns approx Mflops
public static double measureFFT(int N, double mintime, Random R)
{
// initialize FFT data as complex (N real/img pairs)
double[] x = RandomVector(2 * N, R);
//double oldx[] = NewVectorCopy(x);
long cycles = 1;
Stopwatch clock = new Stopwatch();
while (true)
{
clock.Start();
for (int i = 0; i < cycles; i++)
{
FFT.transform(x); // forward transform
FFT.inverse(x); // backward transform
}
clock.Stop();
if (clock.Elapsed.TotalSeconds >= mintime)
{
break;
}
cycles *= 2;
}
// approx Mflops
const double EPS = 1.0e-10;
if (FFT.test(x) / N > EPS)
{
return(0.0);
}
return(FFT.num_flops(N) * cycles / clock.Elapsed.TotalMilliseconds * 1.0e-3);
}