I need to plot the same graphic of the image, but without any loop.

With loop i get this:

   clear
    clc
    x = -5*pi:pi/100:5*pi;
    k = 0;
    y = zeros(size(x));
  
    for k = 0:100
        
        k = k + 1;
        y = y + 2*( ( (-(-1).^k) / k ) .* sin(x*k) );
        
    end
    
    plot(x, y)
    ylabel('f(X)')
    xlabel('X')
    grid

I tried to do this without loop but i getting errors.

clear
clc

x = -5*pi:pi/100:5*pi;
k = 0:1:100;

y = zeros(size(x));

% How to variable k ?
y = y + 2.*( ( (-(-1).^k) / k ) .* sin(x*k) );


sum(x)
sum(y)

plot(x,y)

[KALYAN ACHARJYA]

I didnot find any output using your loop code also.

[Luccas S.]

I ended up not transcribing k = k +1 for publication, now i have changed.

Answer 1

[Walter Roberson]

x = -5*pi:pi/100:5*pi;
k = (1:1:100).';  %not 0!
y = sum(2.*( ( (-(-1).^k)./ k ) .* sin(x.*k) ));

plot(x,y)

[Luccas S.]

Right, I am running the code in octave but it is not working in matlab. (Matrix dimensions must agree.)

[Walter Roberson]

The above code works in R2016b and later.

Octave is not a programming language that I know.

xvals = -5*pi:pi/100:5*pi;
kvals = (1:1:100).';  %not 0!
[x, k] = meshgrid(xvals, kvals);
y = sum(2.*( ( (-(-1).^k)./ k ) .* sin(x.*k) ));

plot(x,y)