How to generate function handle automatically from the cell array?

Question

Akbar 2018-4-12

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/394428-how-to-generate-function-handle-automatically-from-the-cell-array

评论： Akbar 2018-4-13

I have a 2x1 cell called "dx", which contains 1x3 cells:

 'X * k * m'  '*'  '-1'  
 'X * k * m'  '*'  'Y_XS'

I want this "dx" cell to be converted into a function. How can I do that? The generated function should look like this:

 function dX = myFunc(t,X,k,m,Y_XS)
          R = X(2) * k * X(1)/(X(1)+m);
          dX = [-R;
                Y_XS * R];

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Akbar 2018-4-13

编辑：Akbar 2018-4-13

Thank You very much for helping me. I'm developing a script, at the Moment the cell Array that i have is the very first Version, it might change later.

1. No, the size is not always same.

2. Lets assume yes, for simplicity.

3. Yes

4. No

5. Please check this, I have edited the question. Basically I'm trying to create ODE function. x is a variable and others are constants which are available on workspace. I have nothing of type symbolic.

Akbar 2018-4-13

编辑：Akbar 2018-4-13

FYI: I'm reading simulink model which simulates ODE. The Task is to get the Parameters of ODE and create a function inside matlab. So Im getting those Parameters into the cell Array called "dx". Now I want to create a function somehow.

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Answer 1

Stephen23 2018-4-13

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/394428-how-to-generate-function-handle-automatically-from-the-cell-array#answer_314913

编辑：Stephen23 2018-4-13

在 MATLAB Online 中打开

@ashadako: you have since edited your question and completely changed the function specification. This answer give the original specification: you can make the required changes yourself.

The trick is to simply arrange the strings as required, and then use str2func to get a function handle:

dx = {...
 'X * k * m'  '*'  '-1'  
 'X * k * m'  '*'  'Y_XS'};
isn = isnan(str2double(dx(:,3)));
tmp = dx;
tmp(:,4) = {';'};
tmp = tmp(:,4:-1:1).';
str = [tmp{:}];
var = sprintf(',%s',dx{isn,3});
str = sprintf('@(t,X,k,m,%s)[%s];',var(2:end),str(2:end));
fun = str2func(str);