MATLAB: Why should we multiply the number of samples with sound frequency to calculate the sine wave

sine waves

I have a code that aims to produce sine waves for durations of interest. in line related to creating sine wave, it's written:
tone_dur = sin(2*pi*freqs*t);
t is the number of samples needed for each tone duration and freq is the tone frequence (500 Hz). What I don't get is that why should we multiply the number of samples with sound frequency to calculate the sine wave? I don't get the rational!

Best Answer

joly - I think that t is usually a time array (in seconds). From fft examples, t can be initialized as
Fs = 1000;            % Sampling frequency                    
T = 1/Fs;             % Sampling period       
L = 1500;             % Length of signal
t = (0:L-1)*T;        % Time vector
Then you should be able to continue as before.
If t were just the number of samples, i.e. a scalar, then tone_dur would be a scalar value as well....and I don't think that is exactly what you want.
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