Creating a piecewise sine function having different frequency components

Hello,

I am brandnew in Matlab and i would like to generate a piecewise sine function with different frequency components. i.e. a signal at 1 kHz sampling frequency and having 100,200 and 300 Hz frequency components. I check the other topics but couldn't find a proper solution.

[John D'Errico]

Please don't add an answer to an old question just to raise it up. You asked your own question anway.

Answer 1

[Sulaymon Eshkabilov]

Hi,

If I've understood your question correctly, this is what you are trying to create:

fs = 1e3;      % Sampling frequency [Hz]
t = 0:1/fs:1;  % Time space [0, 1] [sec]
f1 = 100;    
f2 = 200;
f3 = 300;
S1 = sin(2*pi*f1*t);
S2 = sin(2*pi*f1*t);
S3 = sin(2*pi*f1*t);
Stotal = S1+S2+S3;
plot(t, Stotal)

Note that your fs is too small (it is better to have your fs = 10[kH]) for your generated frequency components of 100, 200, 300 Hz

[javeria noor]

what to do if we want to multiply s1 and s2

Answer 2

[Star Strider]

Try this:

Fs = 1000;
t = linspace(0, 1, 1E+3)/Fs;                                        % Time Vector (1 sec)
f = 100:100:300;                                                    % Frequency Vector
sm = sin(2*pi*f(:)*t*Fs)';                                          % Signal Matrix
sv = sm(:);                                                         % Signal Vector
tv = (0:numel(sv)-1/Fs)/Fs;

figure
plot(tv, sv)
grid

sound(sv, Fs)                                                       % Listen To The Result

[javeria noor]

what if we want totake product of s1 and s2

Answer 3

[Sulaymon Eshkabilov]

There are two opts. One elementwise multiplication and the other is just product.

% (1) Elementwise:
S1S2_e = s1.*s2;
% (2) Just a product of two row matrix (vector) elements
S1S2_p = s1*s2';