Switching functions smartly, like hash map

In stead of using multiple if-else or switch-case, is there a way of switching functions smartly?

Take if as an example:

for i = 1 : n
    if a
       out(i) = function1(p1,p2,p3);
    else
       if b
           out(i) = function2(p1,p2,p3);
       else
           if c
               out(i) = function3(p1,p2,p3);
           else
               out(i) = function4(p1,p2,p3);
           end
       end
   end
end

Maybe something like funMap = containers.map(key,{function1,...function4}??? So the code will look like:

      for i = 1:n
          key = ...;
          out(i) = funMap(key);
      end

Any thoughts? Thanks in advance!

Answer 1

[Mike]

yes, you can use function handles, and str2fun. Here is a simple example:

function out = foo(funOb,p1,p2,p3)

out = funOb(p1,p2,p3);

where funOb would be a function handle. You could also input a string:

function out = foo(funStr,p1,p2,p3)
funObj = str2func(funStr);
out = funOb(p1,p2,p3);

[Zoe Zhang]

Thanks a lot!

Answer 2

[Andrei Bobrov]

switch p
    case a,   fu = @function1;
    case b,   fu = @function2;
    case c,   fu = @function3;
    otherwise fu = @function4;
end
out = fu(p1,p2,p3);

More

k = [a b c];
fu = {@function1 @function2 @function3 @function4};
t = k == p;  
out = feval( fu{[t ~any(t)]},p1,p2,p3);

[Zoe Zhang]

Thanks a lot, though switch may not work for me this time since my conditions are a little complicated. But great suggestions!