Find frequnecy of a data

Hello hyeee, from above statement i would like to find frequency of x below. i attach my code

%% Find frequency of the x data

x=[-0.7032 0.0299 -0.0173 -0.0299 0.0219 0.0017 0.0071 -0.0166 0.0128 -0.0038 -0.0050 0.0329 0.0153];

p=0;

m=length(x);

y=exp('-jw');

for i=1:m

p=p+x(i)*y^(1-i);

end

display(p);

and i encounter this after run

Undefined function 'exp' for input

arguments of type 'char'.

Error in G12_audio_code_project (line 67)

y=exp('-jw');

any idea what did i do wrong?

[Star Strider]

y = exp(-1j*w);

or, since ‘w’ is not defined, create ‘y’ as an anonymous function:

y=@(w)exp(-1j*w);

Experiment to get the result you want.

.

Answer 1

[Shivang Srivastava]

From what I can understand you are facing trouble using exp() function when you are trying to find the frequency of data in array x.

In my opinion, one of these points is causing you the trouble:

• The function definition of exp() only takes X -Input array which contains datatype single | double.
• If you are trying to use j & w as a variables you should remove the single quotes and declare the variables before using them.

I suggest using the following command if you are taking exponent of your x array

x=[-0.7032  0.0299  -0.0173  -0.0299  0.0219  0.0017  0.0071  -0.0166  0.0128  -0.0038  -0.0050  0.0329  0.0153];
y = exp(x);

Refer to this link to exp() documentations for more information on using exp function: https://in.mathworks.com/help/matlab/ref/exp.html