Re: [amibroker] Re: EasyLanguage CountIf function, AmiBroker Email List Archive

Thanks. I originally misunderstood Cum and Sum are two very different sums (maybe tend to think Cum is related to Cumulative distribution and to be calculated by integration) only re-read the documentaion CAREFULLY that have seen Cum is a subset operation of Sum.

My previous post just wish to clarify that Cum(Inside()) will not do CountIf, but should be Sum(Inside(), Length) because the original statement has a Length parameter. Thanks all.

From: wavemechanic <timesarrow@xxxxxxxxxxxxx>
To: amibroker@xxxxxxxxxxxxxxx
Sent: Saturday, February 14, 2009 9:53:15 PM
Subject: Re: [amibroker] Re: EasyLanguage CountIf function

The first thing to do is to check the syntax for cum() and sum() where all is explained. One gives the cumulative sum from the first bar and the other the cumulative sum for a specified period going backwards from the last bar.

http://www.amibroke r.com/guide/ afl/afl_view. php?id=151

http://www.amibroke r.com/guide/ afl/afl_view. php?id=35

Bill

----- Original Message -----

From: Steve Wong

To: amibroker@xxxxxxxxx ps.com

Sent: February 14, 2009 8:33 AM

Subject: Re: [amibroker] Re: EasyLanguage CountIf function

=> Cum(Inside() )

Cum or inside has not a period/length of bars parameter?

while EasyLanguge' s CountIf(_expression_, Length) can specify the Length, how can I similiarly control the Length when using the Cum?

Ref(Cum(Inside( )), -Length) ? So it will Cum the Length bars only? Sorry I'm still rather newbie to AFL.

From: msc626 <dalmar78@xxxxxxxxxxx net>
To: amibroker@xxxxxxxxx ps.com
Sent: Saturday, February 14, 2009 7:09:12 PM
Subject: [amibroker] Re: EasyLanguage CountIf function

Or Cum(Inside() );

daleb
> Thanks. Your formula should be right.
>
> The documentation of Sum is Sum(Array, Periods). I overlook that
"Low > Ref(Low,-1) AND High < Ref(High,-1) " is array of booleans which
is the beauty of AFL (I originally thought it was only boolean so
can't be applied to Sum).
>
> Thanks for help again.
>
>
>
> ____________ _________ _________ __
> From: Mike <sfclimbers@ ...>
> To: amibroker@xxxxxxxxx ps.com
> Sent: Saturday, February 14, 2009 3:30:51 PM
> Subject: [amibroker] Re: EasyLanguage CountIf function
>
>
> What about:
>
> InsideDays = Sum(Low > Ref(Low, -1) AND High < Ref(High, -1), Length);
>
> Mike
>
> --- In amibroker@xxxxxxxxx ps.com, "swstevewong38" <swstevewong38@ ...>
> wrote:
> >
> > New to Amibroker using it about a week.
> >
> > Translating a piece of code from EasyLanguge.
> >
> > InsideDays = CountIf(Low > Low[1] and High < High[1], Length);
> >
> > Think for a while maybe a combination of AFL's SUM, CUM, BarsSince
> > function can do, but still can't get the correct formula.
> >
> > Is there an equivalent way to express that CountIf in AFL without
> need
> > to write loop?
> >
> > Thanks.
> >
>