Hello, As per request a note that function accepts variable periods has been added to all variable-period functions in the on-line version of the guide.
Best regards, Tomasz Janeczko amibroker.com On 2010-07-15 18:37, rise_t575 wrote: > > Tomasz, > > Thanks for your reply. > > When I say "most", I obviously haven't counted them - it' just that to me (ok > - this is just an opinion), this is the most logical place for such > information. > > --- In [email protected], Tomasz Janeczko<gro...@...> wrote: >> Hello, >> >> Well, variable period functions are listed in one page because in the past >> it was requested to have them listed in one place. >> >> But... I see your point and I agree that some ("most" is debatable) people >> may want to have it the other way. >> >> Best regards, >> Tomasz Janeczko >> amibroker.com >> >> On 2010-07-15 16:25, rise_t575 wrote: >>> Hello, >>> >>> A short definition within each page of the AFL Function Reference/AB manual >>> what type of parameter (scalar/array) is expected/allowed for the >>> corresponding function would be a better place for this old known fact. >>> That's where most people look at in such cases. >>> >>> --- In [email protected], Tomasz Janeczko<groups@> wrote: >>>> Hello, >>>> >>>> It is old, known fact. Some functions accept variable periods. Documented >>>> in the manual: >>>> >>>> http://www.amibroker.com/guide/a_varperiods.html >>>> >>>> >>>> Best regards, >>>> Tomasz Janeczko >>>> amibroker.com >>>> >>>> On 2010-07-15 08:12, Mike wrote: >>>>> Interesting. I ran a quick test and it seems to suggest that Sum does in >>>>> fact take an array as second argument, contrary to expectations. >>>>> >>>>> It would appear that you are correct, with respect to Sum. Though it is >>>>> not always the case that a function with a "periods" argument will accept >>>>> an array. For those that don't, you will have to find another approach. >>>>> >>>>> Here's my test: >>>>> >>>>> Test = Sum(1, Cum(1)); >>>>> Fixed = Sum(1, 5); >>>>> >>>>> Plot(Test, "Test", colorRed, styleLine); >>>>> Plot(Fixed, "Fixed", colorBlue, styleLine); >>>>> Title = "Bar: " + BarIndex() + ", Test: " + Test + ", Fixed: " + Fixed; >>>>> >>>>> If Sum did not accept an array, but was instead substituting some fixed >>>>> number (e.g. last element of the array), then both Plots should result in >>>>> flat lines. However, the test clearly shows that the Test plot rises at a >>>>> 45 degree angle indicating that the period is different at each bar. >>>>> Compare that to the Fixed plot which is constant at a level of 5. >>>>> >>>>> Mike >>>>> >>>>> --- In [email protected], "aaryan111"<aaryan111@> wrote: >>>>>> I guess, sum() is behaving the ideal way :), >>>>>> >>>>>> The most important thing here is, >>>>>> AMIBROKER being an array processing language, calculates all the >>>>>> elements of array , but at any given active bar, it fetches the current >>>>>> value from the whole arry index and shows it to us,Presumably using some >>>>>> barindex kind of mechanism internally. >>>>>> >>>>>> When we put close, open or any array in any afl , like ((close + open + >>>>>> High + Low )/4= MAVG),amibroker produces output based on the current >>>>>> value of that array, we dont need to specify current index of that array >>>>>> (scalar value) to get output at any current bar,it manages it intenally. >>>>>> >>>>>> Here its impotant to not that, its IRRELEVANT if we use array in a >>>>>> Function or simply put it in any statement in afl, it fetches a scalar >>>>>> value out of that produced array to show it to us. >>>>>> >>>>>> when I put SUm(close,Barssince()) It ideally fetches the current element >>>>>> of BarsSince array and place it over ther. >>>>>> >>>>>> This is the ideal way. Sum() is behaving the IDEAL way. >>>>>> infact every other function, >>>>>> let it be , >>>>>> MA(Close,BarsSince(TimeNum()< 093000)); >>>>>> or any other function, having Periods, as a second argument. >>>>>> >>>>>> While in Stdev(),it simply goes against the normal behaviour. >>>>>> it should infact, in MUST , point to the current active element of the >>>>>> Barssince(), let it be a 0 or any other value, its irrelevant, its still >>>>>> a scalar. >>>>>> and it simply doesnt do that!. >>>>>> >>>>>> i think i have made my point clear now. >>>>>> >>>>>> Wave : Lastvalue() will surely fetch the last element of the array, but >>>>>> i cant use it while testing it offline, i will get all future values of >>>>>> that array, its all fine if i have to use it while online updation. >>>>>> >>>>>> >>>>>> >>>>>> Regards... >>>>>> >>>>>> >>>>>> --- In [email protected], "wavemechanic"<olesmithy@> wrote: >>>>>>> I'm fairly sure that the only way you will get StDev() to accept >>>>>>> BarsSince() in the 2nd argument without complaining is to force the >>>>>>> return of a number by use of LastValue() or SelectedValue(). I don't >>>>>>> know why Sum() is not complaining when BarsSince() is used. >>>>>>> >>>>>>> In the Sum() case, I think that BarsSince( TimeNum ... ) is returning a >>>>>>> constant array based on the bar you select, including the last bar if >>>>>>> no bar is selected. If so, that would work OK but does not explain why >>>>>>> StDev() does not work. >>>>>>> >>>>>>> For Sum(), if you replace TimeNum() with another array generator, for >>>>>>> example, MA( C, 13 ) == ...., Sum() still does not complain but >>>>>>> BarsSince() returns 0 (I believe) and, hence, Sum() is 0. >>>>>>> >>>>>>> You might have stumbled onto a unique situation but I would not assume >>>>>>> that it can be generalized and would always go for ensuring the return >>>>>>> of a number from the 2nd argument whether or not the above is correct. >>>>>>> >>>>>>> Bill >>>>>>> ----- Original Message ----- >>>>>>> From: aaryan111 >>>>>>> To: [email protected] >>>>>>> Sent: July 14, 2010 3:08 PM >>>>>>> Subject: [amibroker] Re: Sum and Stdev , wierd behaviour of stdev >>>>>>> >>>>>>> >>>>>>> Hi , thanx for the feedback wave. >>>>>>> its Syntax is basically to put Period as 2nd argument. >>>>>>> When u put an array in SUM() as 2nd argument, it will take the >>>>>>> corresponding scalar frm that array and apply it as a filter. >>>>>>> >>>>>>> i have successfully executed this >>>>>>> >>>>>>> Sum(Close,BarsSince(TimeNum()>092400)); >>>>>>> >>>>>>> regards >>>>>>> >>>>>>> >>>>>>> --- In [email protected], "wavemechanic"<olesmithy@> >>>>>>> wrote: >>>>>>> > >>>>>>> > Neither takes array as 2nd. See syntax in Users Guide. >>>>>>> > ----- Original Message ----- >>>>>>> > From: aaryan111 >>>>>>> > To: [email protected] >>>>>>> > Sent: July 12, 2010 3:41 PM >>>>>>> > Subject: [amibroker] Sum and Stdev , wierd behaviour of >>>>>>> stdev >>>>>>> > >>>>>>> > >>>>>>> > Hi Everybody, >>>>>>> > >>>>>>> > Both Sum() and Stdev() Functions Have same Arguments >>>>>>> Structure.but when i put >>>>>>> > Sum(Close,BarsSince(TimeNum()>092400)) >>>>>>> > it executes successfully,while >>>>>>> > Stdev(Close,BarsSince(TimeNum()>092400)) >>>>>>> > gives a warning " Function Expects Different type of >>>>>>> argument here " . >>>>>>> > >>>>>>> > as far as i understand , both can take array as 2nd >>>>>>> argument and amibroker will automatically fetch the current running >>>>>>> index value of that array as the 2nd argument, same as it does with >>>>>>> other functions. >>>>>>> > >>>>>>> > one can put any other function returning array like >>>>>>> barindex() in 2nd argument , result will be same. >>>>>>> > >>>>>>> > Any suggestions?? >>>>>>> > >>>>>>> > Regards, >>>>>>> > >>>>>>> > >>>>>>> > >>>>>>> > ------------------------------------ >>>>>>> > >>>>>>> > **** IMPORTANT PLEASE READ **** >>>>>>> > This group is for the discussion between users only. >>>>>>> > This is *NOT* technical support channel. >>>>>>> > >>>>>>> > TO GET TECHNICAL SUPPORT send an e-mail directly to >>>>>>> > SUPPORT {at} amibroker.com >>>>>>> > >>>>>>> > TO SUBMIT SUGGESTIONS please use FEEDBACK CENTER at >>>>>>> > http://www.amibroker.com/feedback/ >>>>>>> > (submissions sent via other channels won't be considered) >>>>>>> > >>>>>>> > For NEW RELEASE ANNOUNCEMENTS and other news always check >>>>>>> DEVLOG: >>>>>>> > http://www.amibroker.com/devlog/ >>>>>>> > >>>>>>> > Yahoo! Groups Links >>>>>>> > >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> ------------------------------------ >>>>>>> >>>>>>> **** IMPORTANT PLEASE READ **** >>>>>>> This group is for the discussion between users only. >>>>>>> This is *NOT* technical support channel. >>>>>>> >>>>>>> TO GET TECHNICAL SUPPORT send an e-mail directly to >>>>>>> SUPPORT {at} amibroker.com >>>>>>> >>>>>>> TO SUBMIT SUGGESTIONS please use FEEDBACK CENTER at >>>>>>> http://www.amibroker.com/feedback/ >>>>>>> (submissions sent via other channels won't be considered) >>>>>>> >>>>>>> For NEW RELEASE ANNOUNCEMENTS and other news always check DEVLOG: >>>>>>> http://www.amibroker.com/devlog/ >>>>>>> >>>>>>> Yahoo! Groups Links >>>>>>> >>>>> >>>>> ------------------------------------ >>>>> >>>>> **** IMPORTANT PLEASE READ **** >>>>> This group is for the discussion between users only. >>>>> This is *NOT* technical support channel. >>>>> >>>>> TO GET TECHNICAL SUPPORT send an e-mail directly to >>>>> SUPPORT {at} amibroker.com >>>>> >>>>> TO SUBMIT SUGGESTIONS please use FEEDBACK CENTER at >>>>> http://www.amibroker.com/feedback/ >>>>> (submissions sent via other channels won't be considered) >>>>> >>>>> For NEW RELEASE ANNOUNCEMENTS and other news always check DEVLOG: >>>>> http://www.amibroker.com/devlog/ >>>>> >>>>> Yahoo! Groups Links >>>>> >>>>> >>>>> >>>>> >>> >>> >>> ------------------------------------ >>> >>> **** IMPORTANT PLEASE READ **** >>> This group is for the discussion between users only. >>> This is *NOT* technical support channel. >>> >>> TO GET TECHNICAL SUPPORT send an e-mail directly to >>> SUPPORT {at} amibroker.com >>> >>> TO SUBMIT SUGGESTIONS please use FEEDBACK CENTER at >>> http://www.amibroker.com/feedback/ >>> (submissions sent via other channels won't be considered) >>> >>> For NEW RELEASE ANNOUNCEMENTS and other news always check DEVLOG: >>> http://www.amibroker.com/devlog/ >>> >>> Yahoo! Groups Links >>> >>> >>> >>> > > > > ------------------------------------ > > **** IMPORTANT PLEASE READ **** > This group is for the discussion between users only. > This is *NOT* technical support channel. > > TO GET TECHNICAL SUPPORT send an e-mail directly to > SUPPORT {at} amibroker.com > > TO SUBMIT SUGGESTIONS please use FEEDBACK CENTER at > http://www.amibroker.com/feedback/ > (submissions sent via other channels won't be considered) > > For NEW RELEASE ANNOUNCEMENTS and other news always check DEVLOG: > http://www.amibroker.com/devlog/ > > Yahoo! Groups Links > > > >
