Hello,
i just started coding MQL4, so I have many problems with it
I just want create an indicator which shows/calculate the following:

"1. Graph" = Mom(3) + Mom(5) + Mom(7)
-This should show the speed of change.

In the second window should be shown the following:

"2. Graph" = Mom(Mom(3)) + Mom(Mom(5)) + Mom(Mom(7))
-This should show the acceleration of change.

Later, I need those two calculations for an EA, too. But first I want to get them drawed in an indicator.

Can someone help me?
Here I started to calc the 3-Car-Momentum, but the graph doesn´t work
=========================================
int pos=Bars-counted_bars;
double dMedian ,dMedian1, dResult;
//----main calculation loop
while(pos>=0)
{
dMedian = (High[pos] + Low[pos]) / 2; //medianPrice
dMedian1 = (High[pos+3] + Low[pos+3]) / 2;
dResult = dMedian*100/dMedian1; //Momentum of medianprice
ExtMapBuffer1[pos] = dResult; //fill buffer with results
pos--; //calc next bar
}

I think the error must be in this line:

dMedian1 = (High[pos+3] + Low[pos+3]) / 2;

When i am writing the following:

ExtMapBuffer1[pos] = dMedian;

On the whole chart/indicator-window the median will be calculatet, so the error must be in on of the following lines....

Doesn´t have anybody a good idea??

In the beginning, you will find two bars for which dMedian1 would be zero, and I suspect MT4 gets quite uppity with division by 0. Thus, make sure that pos < Bars - 2.

Thank you very much, that was it!
I have coded this now:

while(pos>=0)
{
dMedian = (High[pos] + Low[pos]) / 2;
dMedian1 = (High[pos+3] + Low[pos+3]) / 2;
if (dMedian1 == 0) dMedian1 = 1;
dResult = dMedian*100/dMedian1;
ExtMapBuffer1[pos] = dResult;
pos--;
}

Now it seems to work.