Use results in the definition of my functions

Question

Florian Spicher 2021-10-17

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1565596-use-results-in-the-definition-of-my-functions

评论： Star Strider 2021-10-17

I would like to use my X(i)s to define my function p, but it says that they are undefined variables or functions. How can I do?

A=[46/15, 5/2, 2/3; 5/2, 8/3, 1; 2/3, 1, 2];
B=[2*exp(1); 2*exp(1); 2*exp(1)-2];
X=linsolve(A,B)
integral(@(x) f(x),0,1)
function p=p(x)
    p=X(1)*x.^2+X(2)*x+X(3);
end
function f=f(x)
    f=(exp(x)-p(x)).^2;
end

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

Star Strider 2021-10-17

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1565596-use-results-in-the-definition-of-my-functions#answer_810241

在 MATLAB Online 中打开

Try this instead —

function pv=p(X,x)
    pv=X(1)*x.^2+X(2)*x+X(3);
end

Here, ‘X’ are the parameters and ‘x’ is the variable. Also, naming the variable inside the function to be the same as the function name confuses MATLAB (and everyone who reads the code).

Beyond that, what the problem and the desired result may be are both not possible to determine, and the parameters ‘X’ are nowhere either defined or calculated, so I’ll stop here.

.

4 个评论
显示 2更早的评论隐藏 2更早的评论

Florian Spicher 2021-10-17

Oh well yeah, you meant the code I published! Then definitely. I thought you meant "the actual purpose of the program makes no sense".

Thank you again for the help!

Star Strider 2021-10-17

As always, my pleasure!

Since I don’t know the actual purpose of the code, I’m in no position to criticise its application. I’m just happy that I was able to help you get it to run! (I didn’t look carefully at the code the first time, so I didn’t notice that the ‘X’ parameters actually existed, and were calculated from the regression.)

.

请先登录，再进行评论。