Series and Simple Functions

[Cab Vinton <cvinton@xxxxxxxxxxxxxx>]

OK, EL jocks, here's a question for you. 

When there are two versions of a function with the same name, one series
and one simple, under what conditions is each one called when it is
referenced by another function, indicator, etc?

For example, below are the series and simple versions of TS's Summation
function. It would seem to me that ideally you'd always want to use the
simple function. It does not refer to prior versions of itself (i.e., is
recalculated from scratch with every bar) and thus any errors will not
be compounded. In that case, why not just delete the series version?
When would the series version be necessary? When is it called, given
that both functions have the same name?

Of course, calculation times are greater for simple functions, but that
is usually not a factor for most of the code that I write.

Many thanks to anyone who can shed some light on this.


Cheers,

CAB VINTON
cvinton@xxxxxxxxxxxxxx

++++++++++++++++++++++++
Summation (Simple)

input:Price(NumericSeries),Length(NumericSimple);
var: Counter(0),Sum(0);

Sum = 0;
For Counter = 0 to Length-1 
begin
        Sum = Sum +Price[Counter];
end;
Summation = Sum;

++++++++++++++++++++++++
Summation (Series)
inputs :  Price(NumericSeries),Length(NumericSimple);
vars    :  Sum(0), Counter(0);

if CurrentBar = 1 
then begin
        Sum = 0;
        for Counter = 0 to Length - 1 
        begin
                Sum = Sum + Price[Counter];
        end;
end
else
        Sum = Sum[1]+Price-Price[Length];

Summation = Sum;