On Sat, 15 Oct 2011, artur bala wrote: You can pass a pointer-to-series as an optional argument (with a default of "null"). If I've correctly understood what you want, here's a simple example. We have a function that computes the sum of its (first) series argument, x. But if a second argument, y, is given it instead computes two sums, returned in a vector, namely the sum of (x at observations where y==0) and sum of (x at observations where y!=0). <hansl> function matrix foo (series x, series *y[null]) matrix ret if isnull(y) print "no y" ret = {sum(x)} else print "got y" ret = {sum(x*(y==0)), sum(x*(y!=0))} endif return ret end function nulldata 20 series x = normal() series y = uniform() > 0.5 matrix m = foo(x, &y) print m matrix m = foo(x) print m </hansl> Allin Cottrell

Suppose that a function contains two (or more) consecutive boolean/int arguments which are provided with a default value. My point is if it could be possible to skip the first boolean/int argument - by leaving a blank for example - and entering only the successive one(s)? E.g. if my function is defined as : my_function(series X, bool tmp1[0], bool tmp2[0]) I'd like to type: my_function(X, , 1) Does it make any sense ? Cheers, Artur