Hi Jess,
Use parentheses:
S = struct('field1',1,'field2',2)
fieldStr = ['fields' num2str(1)]
S.(fieldStr)
ans =
1
Or, with your particular example:
for i = 1:20
val = S.(sprintf('fieldname%02d',i))
end
Please note however that the "right" way to store data from 1 to 20 isn't in a structure with the number built into the name. Instead it sounds like you should be using an array (or cell array if your datatypes are different).
For example:
myData = [12 10 3];
is much cleaner than:
myData.element1 = 12
myData.element2 = 10
myData.element3 = 3
