MATLAB: Convert a datatype (like string) into Simple Plain Text like a Matlab Function

appdesigner

Well in programming we have datatypes that tells the compiler how to see the certain variable. And there are built-in functions imported from libraries, compiler see the whole list of functions (like sin, rand) and compile the behine the scene code.
So, if we have a string like "sin(x)", can we convert it into a simple text sin(x). So in this case instead of taking "sin(x)" as a string, compiler identifies it as a built-in function. In app Designer I want a plot a function that user can define from TextField using MATLAB programming, and the only solution I can think of this is that user can also access the MATLAB functions.
Alternatively, we can say can a user add an input as a MATLAB function, or maybe it could be like –> can we change the functions while the program running.

Best Answer

See str2func(): https://www.mathworks.com/help/releases/R2020a/matlab/ref/str2func.html to convert the string to function handle.
For more advanced cases, see feval(): https://www.mathworks.com/help/releases/R2020a/matlab/ref/feval.html and eval(): https://www.mathworks.com/help/releases/R2020a/matlab/ref/eval.html. However, use them with care and also read this: https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval to see that why using them can be a bad idea if used carelessly:
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