How to implement a conditional function indexed by a specified frequency

I wish to call a function indexed by a designated label (i.e 1,2,3 or 4) across 1000 trials with the frequency of (3,1,1,1) respectively.

i.e the function designated by 1 is 3 times more likely to be called than functions designated by 2,3 and 4 respectively. I was thinking of initialising a vector of 1000 integers (between 1,2,3 and 4) accoridng to the following code:

R = randsample([1 2 3 4], 1000, true, [3 1 1 1])

...Before calling a for loop as follows (forgive the pseudocode);

for i=1:length®;

if '1', then;

'function 1'

if '2', then;

'function 2'

if '3', then;

'function 3'

if '4', then;

'function 4'

... May someone assist me in writing the code (minus specific functions of course). Many thanks.

Answer 1

[Guillaume]

The way I'd do it is put handles to the functions into a cell array:

functionstocall = {@sin, @cos, @log, @exp}; %4 functions for demo
chosenfunction = randsample([1 2 3 4], 1000, true, [3 1 1 1]);
for iter = 1:numel(chosenfunction)
  x = rand;
  y(iter) = functionstocall{chosenfunction(iter)}(x)  %call function index by chosenfunction(iter)
end

No need for a if, just simple indexing.