Function for fourier series
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hello
I have written a function for fourier series but when i try to plot it ,only the consine one shows up did I forget something ? Danke schön
function ft = signal(S,t,A,M,T,N)
for n=1:N
if S=="square"
ft=M+sum(((4*A)./(n.*pi)).*sin((n.*pi)/2).*cos((2*n.*pi.*t)./T));
elseif S=="triangle"
ft=M+sum(((8*A)./(n.^2*pi^2)).*cos((2*n*pi.*t)./T));
elseif S=="saw"
ft=M+sum(-1^(n+1).*(2*A./n.^pi).*sin((2*n.*pi*t)./T));
elseif S=="cosine"
ft=M+A*cos((2*pi.*t)./T);
end
end
%%plot part
M=0;
A=1;
T=10;
t=0:0.1:60;
N=10;
grid on
ft=signal("square",t,A,M,T,N);
plot(t,ft,'r')
hold on
ft=signal("triangle",t,A,M,T,N);
plot(t,ft,'b')
hold on
ft=signal("saw",t,A,M,T,N);
plot(t,ft,'g')
hold on
ft=signal("cosine",t,A,M,T,N);
plot(t,ft,'k')
%%
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Accepted Answer
Star Strider
on 24 Feb 2022
Edited: Star Strider
on 24 Feb 2022
Try this —
%%plot part
M=0;
A=1;
T=10;
t=0:0.1:60;
N=10;
figure
subplot(4,1,1)
ft=signal("square",t,A,M,T,N);
plot(t,ft,'r')
subplot(4,1,2)
ft=signal("triangle",t,A,M,T,N);
plot(t,ft,'b')
subplot(4,1,3)
ft=signal("saw",t,A,M,T,N);
plot(t,ft,'g')
subplot(4,1,4)
ft=signal("cosine",t,A,M,T,N);
plot(t,ft,'k')
%%
function ft = signal(S,t,A,M,T,N)
n=(1:N).';
if S=="square"
ft=M+sum(((4*A)./(n.*pi)).*sin((n.*pi)/2).*cos((2*n.*pi.*t)./T));
elseif S=="triangle"
ft=M+sum(((8*A)./(n.^2*pi^2)).*cos((2*n*pi.*t)./T));
elseif S=="saw"
ft=M+sum(-1.^(n+1).*(2*A./n.^pi).*sin((2*n.*pi*t)./T));
elseif S=="cosine"
ft=M+A*cos((2*pi.*t)./T);
end
end
The loop was not executing correctly. I eliminated the for loop and changed the code to use ‘n’ as a column vector to take advantage of MATLAB’s vectorisation abilities. (I plotted them as subplots because I wanted to see the individual results more clearly.) Otherwise (except for a minor change in the ‘saw’ calculation) the code is unchanged.
EDIT — (24 Feb 2022 at 15:06)
Changed original answer text to one that actually addresses the problem.
.
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