how to find sum of square sine wave

Hi every one; I want to solve that question.Any assistance will be highly appreciable... function called s_wave that computes the sum for each of 1001 values of t uniformly spaced from 0 to 4π inclusive. The input argument is a positive scalar integer n, and the output argument is a row vector of 1001 such sums—one sum for each value of t. You can test your function by calling it with n == 200 or greater and plotting the result, and you will see why the function is called “s_wave”.

Again any assistance will be highly appreciable................

[Image Analyst]

Muhammad, you don't need to add products or tags like matlab, matlab code, matlab function, etc. because everything here is about MATLAB. See Guide to Tags.

Also, MATLAB Coder is a specific product that has nothing to do with the questions you are asking. You probably don't even have any Coder toolbox. http://www.mathworks.com/products/index.html?s_tid=hp_fp_viewall

[Muhammad Usman Saleem]

@thanks Image.. next time i shall take care of it.. Answer my question.. please

[Salaheddin Hosseinzadeh]

Hi Muhammad,

Give it a try it's fairly easy, its a good practice to learn.

Answer 1

[Image Analyst]

Alright, it looks like you need a lot more help than the hints I gave in my other answer. Here is one way to do it (Put all code in both functions into a single "test.m" and run it):

function test
fontSize = 24;
n = 200;
theSum = s_wave(n);
plot(theSum, 'b-', 'LineWidth', 2);

% Fancy up the plot.
grid on;
caption = sprintf('s_wave : Sum of %d terms', n);
title(caption, 'FontSize', fontSize, 'Interpreter', 'none');
xlabel('t', 'FontSize', fontSize);
ylabel('theSum', 'FontSize', fontSize);
% Enlarge figure to full screen.
set(gcf, 'Units', 'Normalized', 'OuterPosition', [0 0 1 1]);
% Give a name to the title bar.
set(gcf, 'Name', 'Demo by ImageAnalyst', 'NumberTitle', 'Off') 

%============================================================
function theSum = s_wave(n)
t = linspace(0, 4*pi, 1001);
for tIndex = 1 : length(t)
  this_t = t(tIndex);
  k = 1 : n;
  numerator = sin(this_t * (2*k-1));
  denominator = 2 * k - 1;
  theSum(tIndex) = sum(numerator ./ denominator);
end

%

[Muhammad Usman Saleem]

thanks @image.. I want to becomes a scientist like you.. one day i hope i will become...............

[Muhammad Usman Saleem]

Thanks @image... Below is my understanding of my your code which is mark in comments..

function theSum = s_wave(n)
% set input argument n
t = linspace(0, 4*pi, 1001);
%using the linspace function generate a vector from 0 to 1001 with step interval of 4*pi.
for tIndex = 1 : length(t)
% loop over the length of vector t
  this_t = t(tIndex);
% i do not get this statement clearly. To me i understand every time the loop run , we call that element of t
  k = 1 : n;
  numerator = sin(this_t * (2*k-1));
  denominator = 2 * k - 1;
  theSum(tIndex) = sum(numerator ./ denominator);
end

[Image Analyst]

Yes, every time you run the loop (do one iteration for one value of t), it will do the sum over k for all values of n. The sum over k=1:n is done "vectorized" rather than using a "for" loop, so each variable (numerator, denominator, theSum(t)) is a vector of n elements.

Answer 2

[Image Analyst]

k = 1 : n;
numerator = sin(t * (2*k-1));
denominator = 2 * k - 1;
theSum = sum(numerator ./ denominator);

this is just very very basic MATLAB vectorization like you learn within the first hour of taking MATLAB training, so you need to look at this link

[Muhammad Usman Saleem]

@Image thanks for your contributions.. Kindly try to understand me what the question ask from me?

[Muhammad Usman Saleem]

To me i understand the question in the following code..

function [sq] =square_wave(n)
k = 1 : n;
numerator = sin(t * (2*k-1));
denominator = 2 * k - 1;
theSum = sum(numerator ./ denominator);

when i check my code i got an error

Feedback: Your program made an error for argument(s) 1

@image guide me about corrections..thanks in advance

[Joseph Cheng]

Kindly put some effort into understanding what Image Analysis has done which gets you 80% of the way there.

Another method is to go

t = 0:.1:4*pi;
k = 1:10;
[T K]= meshgrid(t,k);
Calc= sin((2*K-1).*T)./(2*K-1);