Integration by matlab

Question

reem 2011-5-30

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/8417-integration-by-matlab

采纳的回答： Matt Fig

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Good morning,

Please,I have a problem in integration

please anyone help me and I will appreciate it so much.

My program

N=400;

f1=1; % Frequency of the cosine wave

FS=200; % Sampling Frequency

t=1:400;

n=0:N-1;

X= @(Q)cos((2*pi*f1*n/FS)+Q);

M=quadgk(X,0,(2*pi));

disp(M)

plot(t,M)

grid;

title('cosinewave ');

xlabel('Time index');

ylabel('cosine value');

Kind regards

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Answer 1

Matt Fig 2011-5-30

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/8417-integration-by-matlab#answer_11599

在 MATLAB Online 中打开

Use this instead:

M=quadv(X,0,(2*pi));

%

In the future, you need to be more specific than just saying that you have an error. You should have said this:

This code produces an error, and here is the error message:

??? Error using ==> plus
Matrix dimensions must agree.
Error in ==> @(Q)cos((2*pi*f1*n/FS)+Q)
Error in ==> quadgk>evalFun at 363
            fx = FUN(x);
Error in ==> quadgk>f1 at 381
        [y,too_close] = evalFun(tt);
Error in ==> quadgk>vadapt at 275
            [fx,too_close] = f(x);
Error in ==> quadgk at 214
    [q,errbnd] = vadapt(@f1,interval);
>>

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Matt Fig 2011-5-30

Not when I ran the code. Did you change more than the line I showed you to change? The only line I changed from what you originally pasted was the one line I showed, and I got a plot with no problems.

reem 2011-5-30