Functions have their own workspace, that's the whole points of function. If the function needs R and C, they need to be inputs to the function:
function H = myfunction(f, R, C) %how about a better name for the function? One that actually describes what it does
%..
end
which you call with:
>> myfunction(0:100, R, C)
Note that [0:100] is just a more complicated way of just writing 0:100. It's also marginally slower, since [] is a function call (to horzcat), which in this case does nothing.
