How to Plot a function that contains summation?

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Muhammad Qaisar Fahim
评论： Walter Roberson 2021-9-20
How can I plot the attached two functions with limits from -pi to pi for different values of m ?
  5 个评论
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Muhammad Qaisar Fahim
Muhammad Qaisar Fahim 2021-9-20
With below I am getting an error (Undefined function 'symsum' for input arguments of type 'double'.)
x=[-pi:1:pi]
syms m
figure
for m=1:10
Function_5=(pi/2) + symsum(((2*(-1)^m-1)*cos(m.*x)/pi*m^2),m,0,10)
plot(Function)
hold on
end
Walter Roberson
Walter Roberson 2021-9-20
Ran in:
x=[-pi:0.1:pi]
x = 1×63
-3.1416 -3.0416 -2.9416 -2.8416 -2.7416 -2.6416 -2.5416 -2.4416 -2.3416 -2.2416 -2.1416 -2.0416 -1.9416 -1.8416 -1.7416 -1.6416 -1.5416 -1.4416 -1.3416 -1.2416 -1.1416 -1.0416 -0.9416 -0.8416 -0.7416 -0.6416 -0.5416 -0.4416 -0.3416 -0.2416
figure
for alpha=1:10
m = (1:alpha).';
Function_5 = (pi/2) + sum(((2 .* (-1).^m-1) .* cos(m.*x) ./ (pi .* m.^2)),1);
plot(x, Function_5, 'displayname', "\alpha = " + alpha);
hold on
end
legend show

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采纳的回答

Walter Roberson
Walter Roberson 2021-9-20
Ran in:
alpha = 8;
m = (1:alpha).';
f = @(x) 2/pi + sum(2 .* ((-1).^m - 1)./(pi .* m.^2) .* cos( m.*x ), 1);
fplot(f, [-pi pi])
  3 个评论
显示 1更早的评论
Walter Roberson
Walter Roberson 2021-9-20
Ran in:
syms x m
figure
for alpha=1:10
Function_5 = (pi/2) + symsum(((2*(-1)^m-1)*cos(m.*x)/pi*m^2),m,0,alpha);
fplot(Function_5, [-pi pi], 'DisplayName', "\alpha = " + alpha);
hold on
end
legend show

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