summyia - look at the dimensions of your res array
>> size(res)
ans =
1 8
So it is a single row array with eight columns (or characters since this is a char array). Now, when you look for those elements that are 2 (in your m), the
m == 2
will return a array with a one in the first and fourth position. You then try to insert the string 'worker1' into each of these elements. But remember - the res array is only characters long and you are trying to put the 'worker1' string (which is seven characters) into single character position. The reason that this works in the example is because they are inserting a single character ('z' for example) into any one position of the array. You could do the same here and use a single character to represent your strings, or you would have to use a cell array for res.
res = cell(size(m));
so that you can insert strings into the array. But you will not be able to use your code from above because you are trying to use the equality operator with floating point numbers and this is never recommended or guaranteed to work. I suggest that you loop through each element in your m array and then do a comparison as appropriate
for u=1:size(m,1)
for v=1:size(m,2) % assume 2D only
val = m(u,v);
valAsStr = num2str(val);
if ~isempty(strfind(valAsStr,'3'))
res{u,v} = 'worker4';
elseif val == 2
res{u,v} = 'worker1';
elseif abs(val - 2.5) < eps
res{u,v} = 'worker2';
elseif abs(val - 2.8) < eps
res{u,v} = 'worker3';
end
end
end
For the 2.5 and 2.8 comparisons, we look at the absolute difference between the value and the number we are comparing to. If that difference is less than a small number (our tolerance) then we consider them to be equal.
To check to see if a number contains the number three, we just convert it to a string and look (using strfind) for any occurrences of the '3' character.
