Question

i have strings like these:

s{1,2} = 'string';
s{2,2} = 'string2';

and in workspace structure like this

U.W.string = [2 2.5 3]

I want to check (in loop) s{1,2} or s{2,2} or s{i,2} matches any structure with the same name. If so, assign values from this structure to some variable var(i). How can it be done?

Answer 1

Use isfields to check, if a string is the name of a field in a struct. Then use the syntax struct.(name), where name is a string to access the field. Your code might look something like:

test = struct('hello', 'world', 'count', 42, 'mean', 10);

fields = {'test', 'count';
          'hello', 'text';
          'more', 'less'};
values = {pi, 'dummy', -1};

for row = 1 : size(fields, 1)
    for column = 1 : size(fields, 2)
        if isfield(test, fields{row, column})
            test.(fields{row, column}) = values{row};
        end
    end
end

This converts the initial struct

test =
    hello: 'world'
    count: 42
    mean: 10

to this one

test =
    hello: 'dummy'
    count: 3.1416
    mean: 10

A shorter implementation is achieved by removing the inner loop and giving a cell-array to isfields:

for row = 1 : size(fields, 1)
    %# Note the parenthesis instead of curly braces in the next statement.
    match = isfield(test, fields(row, :));
    if any(match)
        test.(fields{row, match}) = values{row};
    end
end