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metty
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Autogenerating fuctions from syms-Expression

Asked by metty
on 4 Jul 2019
Latest activity Commented on by metty
on 16 Jul 2019
Suppose I have a symbolic expression in Matlab that contains a vector, for example:
syms v1;
syms v2;
vector(1) = sin(v1)+cos(v2);
vector(2) = 1-sin(v1);
Is there a easy way to automatically make a function out of only the variable "vector" that looks something like this?
function vector = myFunction(v1,v2)
vector(1) = sin(v1)+cos(v2);
vector(2) = 1-sin(v1);
end
Of course, it's pointless in this example. I only have a relatively large matrix with long entries instead of the vector.
It would save me a lot of typing.

  1 Comment

This solved it for me:
delete temp.txt
diary temp.txt
for i= 1:length(vector)
X = sprintf('vector(%d)=',i);
disp(X)
vector(i)
end
diary off
%%
find_and_replace('temp.txt', '\n \nans =\n \n', ' ');
find_and_replace('temp.txt', '\n \n', ';\n \n');
With the "find_and_replace" script from here.

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1 Answer

Answer by Chidvi Modala on 16 Jul 2019

I understood that you wanted to create a function which can automatically create equations and store them in a variable ‘vector’.
The below code will help you out
function vector=myFunc
vector{1}=@(v1,v2)(sin(v1)+cos(v2));
vector{2}=@(v1)(1-sin(v1));
end
Use fsolve to solve the above equations.

  1 Comment

My initial situation was not the function, but the vector with syms entries. In my specific case, a matrix. The individual terms in the matrix are very large, and it would take me a day to type them out.

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