How to generate noise from 950 to 1050 Hz for 0.2 sec?

How to generate noise from 950 to 1050 Hz for 0.2 sec? Please help me.

[Image Analyst]

How many elements do you want? Note that you should have at least enough to satisfy the Nyquist frequency. As long as you have that, you're free to have as many elements as you want define the 0.2 seconds. How about a million points?

[Image Analyst]

I didn't answer. I asked clarifying questions. The answer(s) are below.

Answer 1

[Thiago Henrique Gomes Lobato]

Choose Fs, generate broadband noise, filter with a bandpass:

Fs = 44100;
Tmax = 0.2;
Samples = Tmax*Fs;
noise   = randn(Samples,1);
noise = bandpass(noise,[950 1050],Fs);
pspectrum(noise,Fs)

[Parisa]

thank you for answering my question. but when I use this code, there is an error : noise = bandpass(noise,[950 1050],Fs);

[Thiago Henrique Gomes Lobato]

Every time you have an error it is good to show the actually error message so we can now what actually happened. I would guess that either your matlab version does not have the function bandpass or you don't have the signal processing toolbox. The following solution should work in either case:

Fs = 44100;
Tmax = 0.2;
Samples = Tmax*Fs;
noise   = randn(Samples,1);

% Take fft of the noise
fftNoise  = fft(noise);
Freqs= [0:size(fftNoise,1)-1]/size(fftNoise,1)*Fs; % Freq Vector

% Get index for your Frequencies
[~,Pos950] = min(abs(Freqs-950)); 
[~,Pos1050] = min(abs(Freqs-1050)); 

% "zero out" all other bins
fftNoise(1:Pos950) = randn(Pos950,1)*1e-3;
fftNoise(Pos1050:end) = randn(size(fftNoise,1)-Pos1050+1,1)*1e-3;

% Get back time signal
noise  = ifft(fftNoise,'symmetric');

figure,plot(Freqs,10*log10(abs(fft(noise))))
xlim([900,1200])
xlabel('Frequency [Hz]')

[Thiago Henrique Gomes Lobato]

sound(noise,Fs)

Keep in mind that 0.2 s is almost nothing

[Parisa]

I know..thanks alot