There's an example in LRM 2.3.1, section 4.7.1:

Example 3 — Initialization of a vector variable
The analog user defined function called arrayadd adds the contents of a second array to the first.
Code:

  analog function real arrayadd;
    inout [0:1]a;
    input [0:1]b;
    real a[0:1], b[0:1];
    integer i;
    begin
      for(i = 0; i < 2; i = i + 1) begin
        a[i] = a[i] + b[i];
      end
    end
  endfunction
 

I can't say whether it works in all simulators.