Handling UITable Cell Array

Hello Matlab Community,

I am trying to code the GUI for my thesis,

I used UITable, in the table I input the initial condition which is a value always, and the next column is the deterioration equation in time. Example equations: e^t, sin(t), t^2 - 2t, t and so on.

I would like to be able to create an array of equations using the the approach t0 + f(t), but UITable stores the data in cell format and thus my question is, how can I convert the data in order to utilize them effectively as equations in matlab.

Answer 1

[Walter Roberson]

In a situation like that, you would probably get() the Data property of the uitable, and then for each position where an equation was expected, using {} indexing to extract the string stored there. Then you would probably use str2func() to turn the expression into a function handle that you could execute. If you have the symbolic toolbox it can make sense sometimes to sym() the string instead of str2func() -- though using sym() for that is likely to generate a warning these days.

[Samer El Zahab]

I tried your approach, but I am struggling with str2func(). completeData is the data collected from the gui, I isolated the cell columns with equations, yet for some reason I am unable to convert them to functions. The code is as follows:

functionA = completeData(:,3); 
functionB = completeData(:,5); 
n = size(functionA,1); %Determine total count of Data
equationsA=[];
equationsB=[]; 

for i = 1:1:n 

equationsA = [equationsA; sym((functionA(i,1)))];
equationsB = [equationsB; sym((functionB(i,1)))]; 

end

[Walter Roberson]

You can replace the above with

equationsA = sym( completeData(:,3) );
equationsB = sym( completeData(:,5) );

Note that the results will be a vector of symbolic expressions, not functions. If you want symbolic functions, then

equation_vars = [x, y];
equationsA = cellfun(@(F) symfun(sym(F), equation_vars), completeData(:,3), 'Uniform', 0);
equationsB = cellfun(@(F) symfun(sym(F), equation_vars), completeData(:,5), 'Uniform', 0);

This would give you a cell array of symbolic functions. You need to store them in a cell array in order to access them individually

equationsA{1}(pi, 19)     %for example