double integral with one variable

Question

Ozan 2012-11-26

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/54861-double-integral-with-one-variable

Hi, I have been struggling to understand below double integral phenomenon. I am trying to solve an loop problem and in one small part of loop I need to take an definite double integral. If the formula contains two variables, I can get the correct answer. But, if the formula has just one variable (as shown below) I get the below error. How can I handle this problem?

Here is my simplified code;

syms x y;

A2=y^3;

f= matlabFunction(A2);

integrand = @(x,y)f(x,y);

Q2 = quad2d(integrand,-1,1,-1,1);

And the error I get from Matlab is below:

??? Error using ==> sym.matlabFunction>@(y)y.^3

Too many input arguments.

Error in ==> @(x,y)f(x,y)

Error in ==> quad2d>tensor at 355

Z = FUN(X,Y); NFE = NFE + 1;

Error in ==> quad2d at 169

[Qsub,esub] = tensor(thetaL,thetaR,phiB,phiT);

Error in ==> example at 7

Q2 = quad2d(integrand,-1,1,-1,1);

I would appreciate any help, idea, thought...

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Walter Roberson 2012-11-26

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/54861-double-integral-with-one-variable#answer_66586

matlabFunction() by default creates a function handle that expects only as many input parameters as there are free variables in the symbolic function. You should specifically tell matlabFunction() which variables you wish to have in the calling sequence and in which order.