# need help solving this summation

1 回表示 (過去 30 日間)
Luke Radcliff 2016 年 6 月 10 日
コメント済み: Roger Stafford 2016 年 6 月 11 日
I need to solve this, but keep getting an error about the matrix, probably dealing with the x and y variables set.
L=3; W=5; x=linspace(0,L,10);
y = linspace(0,W,7); N=9;
P = 1:2:N
w = 2/pi .* sum(2./P .* sin(P.*pi.*x./L) .* (sinh(P.*pi.*y./L) ./ sinh(P.*pi.*W./L)))
there is a picture attached, showing the summation, I might not even be doing this right Im new to matlab. It has to be done using the sum function not symsum, a for loop also can be done to solve this if possible.
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Walter Roberson 2016 年 6 月 10 日
That image is too small to read clearly.
Luke Radcliff 2016 年 6 月 10 日
Okay I enlarged the image

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### 採用された回答

Roger Stafford 2016 年 6 月 11 日
Make these changes in your code:
L=3;
W=5;
x=linspace(0,L,10);
y = linspace(0,W,7);
N=9;
P = 1:2:N
for ix = 1:10
for iy = 1:7
w(ix,iy) = 2/pi .* sum(2./P .* sin(P.*pi.*x(ix)./L) .* (sinh(P.*pi.*y(iy)./L) ./ sinh(P.*pi.*W./L)));
end
end
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Luke Radcliff 2016 年 6 月 11 日
wouldnt I not need the sum function any more since its a for loop now.
Roger Stafford 2016 年 6 月 11 日
You need to sum with respect to the five values in P. Either do it with the 'sum' function or make another nested for-loop (the latter of which seems a little unnecessary - 'sum' does its job quite well.)

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