₦airaland Forum

I am new to matlab and have been trying to do a loop for a program but keep getting errors some please help on how to go about it. here's the problem:
sig=sumcos(f,A,P,fs,dur);
let
fk = kf0, Ak = 4/(k*pi), Pk = pi/2 for k = 1,3,5 . . .

fk = 0, Ak = 0 , Pk = 0 k = 0,2,4,,
4
Use your sumcos function with f0 = 25Hz, fs = 8000, dur =1/f0 sec and N= 5, 10,15, 20 and 25 to plot the synthesized periodic discrete waveform. Use the hold on command to show all signals together. Note Matlab index starts from 1,2,3 ,
the code I am supposed to modify is:

function sig=sumcos(f,a,p,fs,dur)

if (nargin == 0)
f=100;
a=2.0;
p=50;
fs=8000;
dur=0.01;
end
num=length(f);
x=a.*exp(j*p);
t=0:1/fs:dur;
arg=j*2*pi*f'*t;
sig=real(x*exp(arg))


thanks guys

Morning guys, still expecting a reply. Thanks

See here: http://pastebin.com/SjpRhP4q

I'm also not sure why that sumcos() function is so hideous.

This is clearer and more concise:

function sig=nl(f,a,p,fs,dur)
% Default parameters.
if (nargin == 0)
    f=100; a=2.0; p=50; fs=8000; dur=0.01;
end
w = 2*pi*f;
t=0:1/fs:dur; 
sig=a*cos(p+w*t);

Thanks man, it is used to call the function from matlab. It can be anything. Just a name. I can type in sumcos in matlab and fill in the arguments. Have a crude solution though. looking to refine it

Also I tried the code and it ran just that it does not retain the 5 plots together. then the formula for sig was not used.

x=a.*exp(j*p);
t=0:1/fs:dur;
arg=j*2*pi*f'*t;
sig_out=real(x*exp(arg));

Err I think i've given you pretty much everything you need to solve the problem at this point. Just tweak what I linked to to serve your purposes

Yea thanks alot. That link was very helpful too,never knew there was something like that.