Assign a cell data that starts with a regular expression

An m-file contains a (1 by 4) cell data that may have different name, for example Fsim, FsimData, FsimName etc.

What I want to do is after loading the m-file, assign the cell data to a new variable called 'myData' as long as their name start with 'Fsim'.

How can I achieve this?

% Loading the file
load(fileName,'.mat')
% The file contains only one cell data (1 by 4), which may be named
% differently: Fsim, FsimData, FsimName etc.
% I want to assign the cell data to 'myData' as long as the cell name start with 'Fsim'.
myData=Fsim(followed by regular expression);

Answer 1

[Stephen23]

Always LOAD into an output variable! That will make your code much more reliable, and makes this task easier.

Method 1: the simplest approach is to use LOAD's syntax which already supports regular expressions:

fnm = sprintf('%s.mat',fileName);
raw = load(fnm,'-regexp','^Fsim');
myData = struct2cell(raw)

See: https://www.mathworks.com/help/matlab/ref/load.html#btm0etn-1-variables

Method 2: check the output variable's fieldname:

raw = load(fnm);
fld = fieldnames(raw);
assert(numel(fld)==1,'You said only one variable!')
idx = startsWith(fld,'Fsim'); % or STRNCMP
if idx
    myData = raw.(fld{1}); % dynamic fieldname
end

https://www.mathworks.com/help/matlab/matlab_prog/generate-field-names-from-variables.html

Method 3: use STRUCT2CELL and some indexing, e.g.:

obj = struct2cell(raw);
myData = obj(idx);

[yp78]

Thanks so much for the tips. I was doing something similar to method 2, but the use of 'fieldnames' was something that I was missing through out.