use nested functions in matlab M-file - matlab

Question

i have question,about which i am too much interested,suppose that i have two M-file in matlab, in the first one i have described following function for calculating peaks and peaks indeces
function [peaks,peak_indices] = find_peaks(row_vector)
A = [0 row_vector 0];
j = 1;
for i=1:length(A)-2
temp=A(i:i+2);
if(max(temp)==temp(2))
peaks(j) = row_vector(i);
peak_indices(j) = i;
j = j+1;
end
end
end
and in second M-file i have code for describing sinusoidal model for given data sample
function [ x ]=generate(N,m,A3)
f1 = 100;
f2 = 200;
T = 1./f1;
t = (0:(N*T/m):(N*T))';
wn = rand(length(t),1).*2 - 1;
x = 20.*sin(2.*pi.*f1.*t) + 30.*cos(2.*pi.*f2.*t) + A3.*wn;
end
my question is how to combine it together?one solution would be just create two M-file into folder,then call function from one M-file and made operation on given vector and get result,and then call second function from another M file on given result and finally get what we want,but i would like to build it in one big M-file,in c++,in java,we can create classes,but i am not sure if we can do same in matlab too,please help me to clarify everything and use find_peaks function into generate function
UPDATED:
ok now i would like to show simple change what i have made in my code
function [ x ] = generate(N,m,A3)
f1 = 100;
f2 = 200;
T = 1./f1;
t = (0:(N*T/m):(N*T))'; %'
wn = rand(length(t),1).*2 - 1;
x = 20.*sin(2.*pi.*f1.*t) + 30.*cos(2.*pi.*f2.*t) + A3.*wn;
[pks,locs] = findpeaks(x);
end
i used findpeaks built-in function in matlab,but i am getting following error
generate(1000,50,50)
Undefined function 'generate' for input arguments of type 'double'.
also i am interested what would be effective sampling rate to avoid alliasing?

Answer 1

You can simply put both in one file. The file must have the same name as the first function therein, and you will not be able to access subsequently defined functions from outside that file. See the MATLAB documentation on functions http://www.mathworks.co.uk/help/matlab/ref/function.html (particularly the examples section).
Also note that MATLAB has a built-in function findpeaks().
(By the way, you're still sampling at too low a frequency and will most certainly get aliasing - see http://en.wikipedia.org/wiki/Aliasing#Sampling_sinusoidal_functions )
Edit: As you requested it, here is some more information on the sampling theorem. A good and simple introduction to these basics is http://www.dspguide.com/ch3/2.htm and for further reading you should search for the Shannon/Nyquist sampling theorem.

Answer 2

Try with this, within a single MATLAB script
function test()
clc, clear all, close all
x = generate(1000,50,50);
[p,i] = find_peaks(x)
end
function x = generate(N,m,A3)
f1 = 100;
f2 = 200;
T = 1./f1;
t = (0:(N*T/m):(N*T))'; %'
wn = rand(length(t),1).*2 - 1;
x = 20.*sin(2.*pi.*f1.*t) + 30.*cos(2.*pi.*f2.*t) + A3.*wn;
end
function [peaks,peak_indices] = find_peaks(row_vector)
A = [0;row_vector;0];
j = 1;
for i=1:length(A)-2
temp=A(i:i+2);
if(max(temp)==temp(2))
peaks(j) = row_vector(i);
peak_indices(j) = i;
j = j+1;
end
end
end