complex sine graph plotting I need help

my complex sine graph is 1050 points. I want it to be just 100 points for some other math calculations. here is the function. can someone please fix it for me so that stpFunc is 100 instead of 1050 and still graphs similarly, thanks a ton!

   n = 1050; 
    w = [0:.005:1-0.005]';  
    w=repmat(w,5,1); %repmat(w,10,1);
    w=[zeros(50,1);w];

    t=[zeros(50,1)];
for i=1:5 %10
    t=[t;i*ones(200,1)];
end
stpFunc = sin(2*pi*w.*t);
complex_sine = stpFunc'
figure; plot(stpFunc,'linewidth',3);

[Azzi Abdelmalek]

Can you explain what your code is doing?

[Osita Onyejekwe]

if you copy and paste it into the command window, it is just a sine graph that looks cool. if you say length(stpFunc) it says 1050, i just want it to be reduced to 100 so that i can put it into a a matrix of other signals i am working on

Answer 1

[Star Strider]

I do not understand everything you are doing. If you want ‘w’ to have a length of 100, use the linspace function:

w = linspace(0, 1, 100);

I cannot follow what you are doing with the rest of your code, so you will have to change it to work with the new ‘w’.

[Osita Onyejekwe]

i want stpFunc to have a length of 100....

[Star Strider]

This interpolates the original to be a length of 100, but even using the 'spline' interpolation method, the undersampling does not reproduce the original look of the function.

n = 1050;
w = [0:.005:1-0.005]';
w=repmat(w,5,1); %repmat(w,10,1);
w=[zeros(50,1);w];

t=[zeros(50,1)];
for i=1:5 %10
    t=[t;i*ones(200,1)];
end
stpFunc0 = sin(2*pi*w.*t);                                          % Original ‘stpFunc’
stpFunci = linspace(1, length(stpFunc0), 100);                      % Interpolation Vector
stpFunc = interp1([1:length(stpFunc0)],stpFunc0,stpFunci,'spline'); % Interpolated ‘stpFunc’
complex_sine = stpFunc';
figure; plot(stpFunc,'linewidth',3);

[Osita Onyejekwe]

thank you so much, this will do!!!

[Star Strider]

My pleasure!

If my Answer solved your problem, please Accept it.

Answer 2

[Osita Onyejekwe]

basically i want this entire graph to be in the domain to 100 instead of 1050..im just not sure how to scale it all down..can someone please help me?