New Post: Numerics FFT result interpretation

I am new to Math .net numerics and still trying to understand the FFT library. Based on the some examples, I've written following code:

            Complex[] samples = new Complex[1000];
            double[] s =  Generate.Sinusoidal(1000, 2000.0, 200.0, 10.0);
            for (int i = 0; i < 1000; i++)
                samples[i] = new Complex (s[i],0);

            for (int i = 0; i < samples.Length; i++)
            {
                chart1.Series["Series1"].Points.AddXY
                        (i,samples[i].Real);

            }
            Fourier.Forward(samples,FourierOptions.Matlab);

            for (int i = 0; i < samples.Length; i++)
            {
                chart2.Series["Series1"].Points.AddXY
                        (i, samples[i].Real);

            }

based on my understanding of FFT, i should get impulse at 200Hz and frequency resolution should be fs/N.
But the peak is coming at 900th sample, which i'm not sure pointing to 200Hz. If my interpretation is correct?
Any help would be appreciated. Thanks in advance.