Give this code a shot. You would be able to make the variable "data" listed here as a vector of whatever data you like and this should still work. If you had a matrix instead of a vector, however, you would need to loop around both the rows and columns.
a = 20;
b = 10;
c = 30;
data = [a,b,c];
largest = data(1);
for i = 1:length(data)
if data(i) > largest;
largest = data(i);
end
end
