I am creating a function which scans files for a certain function and determines which variables (all are already initialized) are used as parameters for the function. Currently, I am able to derive a cell array with strings for each individual variable. The program takes this:
x = DummyFunction(a, b, c);
And returns this:
{'a'} {'b'} {'c'}
I am trying to convert these strings, which contain pre-established variables, into variables which can be called. Any suggestions?
The function you're looking for is matlab.lang.makeValidName (introduced in R2014a):
N = matlab.lang.makeValidName(S)constructs valid MATLAB® identifiers,N, from input strings,S. ThemakeValidNamefunction does not guarantee the strings inNare unique.A valid MATLAB identifier is a character vector of alphanumerics (A–Z, a–z, 0–9) and underscores, such that the first character is a letter and the length of the character vector is less than or equal to namelengthmax.
makeValidNamedeletes any whitespace characters before replacing any characters that are not alphanumerics or underscores. If a whitespace character is followed by a lowercase letter,makeValidNameconverts the letter to the corresponding uppercase character.
So for example:
>> matlab.lang.makeValidName(["_privateField", "some name"])
yields:
ans =
1×2 string array
"x_privateField" "someName"
I am not sure it applies to your use case, but you might want to look at: Why Variables Should Not Be Named Dynamically (eval).
Perhaps what you really want to do is check whether variables with certain names exist, then do something accordingly - in which case you could use the exist function:
tf = exist('varName','var')
So for example:
if exist('a','var') && exist('b','var')
res = someFunction(a,b);
else
res = someFunction(default_a,default_b);
end
Try storing your variables in a structure and use dynamic field referencing. Here is an example:
variables.a = 1;
variables.b = 2;
variables.c = 3;
% scan your file here
% let's assume a and b are found in the file
variables_present = ['a', 'c'];
for i = 1:length(variables_present)
% use dynamic field reference
disp(variables.(variables_present(i)))
end
This will produce the output:
1
3
Follow this link for more information on how to use dynamic field referencing:
eval()function. It's better to forget it even exists - since it only leads to bad programming practices.