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Here is my code:

clearvars;
clc; 
close all;

%Define the domain: 
l=1;
%and consider, say, 4 periods
x=linspace(-4,4);
%Define the number of terms to consider
n_tot=50;
%Initialize the vectors containing each term of the series
FSS_term_x=zeros(n_tot,length(x));
%Loop to compute each term of the series up to n_tot
for n=1:n_tot
    %n-th term of the series for f(x)=x
    FSS_term_x(n,:)=((-2.*l.^2./n.pi).*cos(n.*pi)+2.*(l.^2)./(n.*pi).^2.*(cos(n.*pi)-1)).*sin(n.*pi.*x./l);
    %-2.*l./(n.*pi).*cos(n.*pi).*sin(n.*x.*pi/l);
end
%Add up all the terms of the series
FS_y=sum(FSS_term_x,1);
%Plot the series
figure
plot(x,FS_y)

and here is the error message:

Dot indexing is not supported for variables of this type.

Error in untitled3 (line 16)
    FSS_term_x(n,:)=((-2.*l.^2./n.pi).*cos(n.*pi)+2.*(l.^2)./(n.*pi).^2.*(cos(n.*pi)-1)).*sin(n.*pi.*x./l);

Does this error occur because the Fourier Sine Series I am trying to graph is piece-wise smooth?

Any feedback is appreciated!

Best,

RK

Ryan Krieger
  • 1

1 Answers1

1

You miss a multiplication (*) sign in the expression in your for loop. It regards the first bracketed term on the rhs: in your code it says (-2.*l.^2./n.pi) (notice the n.pi at the end!), while it should be (-2.*l.^2./n.*pi).

So, the expression in the for loop should be:

FSS_term_x(n,:)=((-2.*l.^2./n.*pi).*cos(n.*pi)+2.*(l.^2)./(n.*pi).^2.*(cos(n.*pi)-1)).*sin(n.*pi.*x./l);
    %-2.*l./(n.*pi).*cos(n.*pi).*sin(n.*x.*pi/l);
DeX97
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