Plotting a summation with two variables

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Alice K 2023-4-6

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https://ww2.mathworks.cn/matlabcentral/answers/1942804-plotting-a-summation-with-two-variables

评论： Alice K 2023-4-6

采纳的回答： Torsten

Hi All,

I need to plot a summation but I keep getting a blank plot,

Any help you can give would be great.

Here is my summation:

Here is the code I have tried:

t = linspace(0,0.01,1);

x = linspace(0,0.01,1);

n = 100;

for k = 0:1:n

y = (6/(pi+6*k*pi))*sin(k*x)*exp((-(pi/6+k*pi)^2)*t);

end

plot(v,t)

Thanks

Alice

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采纳的回答

Torsten 2023-4-6

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https://ww2.mathworks.cn/matlabcentral/answers/1942804-plotting-a-summation-with-two-variables#answer_1210999

编辑：Torsten 2023-4-6

在 MATLAB Online 中打开

t = linspace(0,0.1,100);

x = linspace(0,1,100).';

n = 1000;

f = @(t) sum(6./(pi+6*(0:n)*pi).*sin(x.*(0:n)).*exp(-(pi/6+(0:n)*pi).^2*t),2);

for j = 1:numel(t)

F(:,j) = f(t(j));

end

figure(1)

plot(x,[F(:,1),F(:,10),F(:,15),F(:,20),F(:,100)])

figure(2)

plot(t,[F(1,:);F(10,:);F(15,:);F(20,:);F(100,:)])

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Torsten 2023-4-6

编辑：Torsten 2023-4-6

在 MATLAB Online 中打开

You can use

t = linspace(0,0.1,100);
x = linspace(0,1,100).';
n = 1000;
f = @(t) sum(6./(pi+6*(0:n)*pi).*sin(x.*(0:n)).*exp(-(pi/6+(0:n)*pi).^2*t),2);
for j = 1:numel(t)
    F(:,j) = f(t(j));
end

t = linspace(0,0.1,100);
x = linspace(0,1,100).';
n = 1000;
f = @(t) sum(6./(pi+6*(0:n)*pi).*sin(x.*(0:n)).*exp(-(pi/6+(0:n)*pi).^2*t),2);
F = cell2mat(arrayfun(@(t)f(t),t,'UniformOutput',0));

t = linspace(0,0.1,100);
x = linspace(0,1,100).';
n = 1000;
F = zeros(numel(x),numel(t));
for i = 1:numel(x)
    xv = x(i);
    for j = 1:numel(t)
        tv = t(j);
        for k = 0:n
            F(i,j) = F(i,j) + 6/(pi+6*k*pi)*sin(xv*k)*exp(-(pi/6+k*pi)^2*tv);
        end
    end
end