Todd, > Index = Ref(Index,1) * Multiplier
A few observations: 1. You should use Ref(..., -1) if you want the previous bar's value. 2. Uninitialized variable errors come from trying to use a variable that has not yet been assigned a value. In your example, if this is the first time you are assigning a value to Index, then the problem may be that you are trying to use a value (i.e. Index) that has not yet been defined (i.e. what do you expect to be in Ref(Index, ...) when Index itself has not yet been set to anything?). 3. Note that the values for an array are all set at the same time, not sequentially bar by bar: http://www.amibroker.com/guide/h_understandafl.html When trying to calculate current array values based on earlier values from that same array (e.g. current value is a multiple of the previous value), you will usually have to use looping code. Though, you may be able to use AMA or AMA2 to do the job for you. http://www.amibroker.com/guide/afl/afl_view.php?id=18 http://www.amibroker.com/guide/afl/afl_view.php?id=19 Mike -- In amibroker@yahoogroups.com, "toddk63" <[EMAIL PROTECTED]> wrote: > > Thanks Mike. I had read that doc. And I did notice I had to run > "Explore" a couple of times to get things to "converge" properly. > > My basic problem is I cannot use yesterdays "Index" times the > "Multiplier" to get todays "Index". Something like: > > Index = Ref(Index,1) * Multiplier > > This doesn't work and gives an error. Something about using an > un-initialized variable. > > Todd K. > > --- In amibroker@yahoogroups.com, "Mike" <sfclimbers@> wrote: > > > > Hi, > > > > You may find the following document useful for some ideas (thanks to > > Herman): > > > > http://www.amibroker.org/3rdparty/IntroToAtc.pdf > > > > Additionally, be sure to study page 17 to ensure that your immediate > > Foreign usage of ~MyIndex within a single exploration is behaving as > > you expect. > > > > Mike > > > > --- In amibroker@yahoogroups.com, "toddk63" <toddk63@> wrote: > > > > > > I have created a custom "Index" using "AddToComposite". Here is the > > > code that runs in Exploration: > > > ----------------------------------------- > > > Counter = IIf(IsNull(Close),0,1); > > > > > > AddToComposite( Counter * ROC(Close,1), "~MyIndex", "C", 1+2+8+16 ); > > > AddToComposite( Counter, "~MyIndex", "I", 1+2+8+16 ); > > > > > > Index = 100 + Cum(Foreign( "~MyIndex", "C" ) / Foreign( "~MyIndex", > > > "I" )); > > > > > > Multiplier = (100 + Foreign( "~MyIndex", "C" )/Foreign( "~MyIndex", > > > "I" ))/100; > > > > > > Filter=1; > > > > > > AddColumn (Close,"Close"); > > > AddColumn (Index,"Index"); > > > AddColumn (Multiplier*100,"Multiplier x 100"); > > > -------------------------------------------------- > > > The problem is using the "CUM" function adds the daily percent > > change > > > to calculate the "Index". I wish to use the "Multiplier" to > > calculate > > > an index where the previous days index value is multiplied by the > > > "Multiplier". The index should initialize as "Index = 100" to start > > > with the first bar. Its probably simple fix, but I can't get there. > > > > > > Frustrated, > > > > > > Todd K. > > > > > >
