Ok, let me see if I understand what is happening at each statement of the code.
Sum50[i] = Sum50[i-1] + Close[i];
For each bar add the current close to the previous accumulated value of closes.
if(i > 50) Sum50[i] = Sum50[i] - Close[i - 50];
For each bar beyond the 50th bar subtract the close of the bar 50 places backward from current bar.
if(i >= 50) MA50[i] = SUM50[i] / 50;
For each bar greater than or equal to 50 take the accumulated total from the contiguous 50 bars and divide it by 50 which calculates the average.
Please correct me if I missed something. But I do believe I understand what is happening at each iteration of the loop.
Thank you Tony for providing that very simple example so I could get my mind around the concept.
Pete :-)
--- In
amibroker@xxxxxxxxxxxxxxx, Tony Grimes <Tonez.Email@xxx> wrote:
>
> Here is a version that will match the 50 MA from Amibroker:
> Sum50 = 0;
> MA50 = Null;
>
> for(i = 1; i < BarCount; i++)
> {
> Sum50[i] = Sum50[i-1] + Close[i];
>
> if(i > 50) Sum50[i] = Sum50[i] - Close[i - 50];
>
> if(i >= 50) MA50[i] = SUM50[i] / 50;
> }
>
>
> Plot(MA50,"50 MA via Looping", colorRed, styleLine);
> Plot(MA(C,50),"50 MA via Built in Function", colorBlack, styleLine);
>
>
> On Sat, May 2, 2009 at 4:37 PM, Pete <dryheat3@xxx> wrote:
>
> >
> >
> > Ok, first off, I apparently don't have the first clue about how to right
> > code that loops through an AB database. I am pretty fluent with looping
> > through MS Access databases using VBA but when it comes to AB I am
> > completely lost.
> >
> > So in my endeavor to educate myself on the ins and outs of looping in AB I
> > decided to try creating a very simple 50 period moving average using a for
> > loop. My results are below but it does not work.
> >
> > I am defeated and at my wits end. Despite all this time and effort I have
> > gained absolutely nothing which helps understand what is happening at each
> > bar during a loop beyond measuring a single value for a single bar. What I
> > am trying to understand is how to accumulate values over a period of bars
> > and output the accumulated value for each and plot it on a chart.
> >
> > Seems simple enough, add the closes of 50 consecutive bars, store the
> > result in a variable and divide that variable by 50. I can either do this
> > for all bars or one bar but have not been able to figure out how to do it
> > for EVERY bar.
> >
> > Thanks for taking the time to look at this.
> >
> > Pete :-)
> > //Code Begin@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
> > Cnt[0] = 0;
> > SumOfClose[0] = 0;
> > for( i = 1; i < BarCount; i++ )
> > {
> > if(Cnt[i] < 50)//check if counter is less than 50
> > {
> > //if counter less than 50 add current bar's
> > //close to the previous running total
> > SumOfClose[i] = (SumOfClose[i-1] + C[i]);
> > //increment counter by + 1 each bar
> > Cnt = Cnt + 1;
> > }
> > if(Cnt[i] == 50)//check if counter is equal to 50
> > {
> > //if counter = 50 than compute
> > //the 50 period MA
> > MAline[i] = SumOfClose[i]/50;
> > //reset counter to zero
> > Cnt = 0;
> > }
> > }
> > //plot the result
> > Plot(MAline, "MA 50", colorBlue, styleLine);
> > //Code End@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
> >
> >
> >
>