Help with EMA(); Series Needed?

[zmendel]

What I want to accomplish is the following:
1- Run the calculation in Line 10 (That works); then,
2- Calculate an EMA of line 10, in line 11; then,
3- Calculate another EMA (double smoothing) in line 12 of line 11; then,
4- Return the results in vEMAsN.

CODE SAMPLE:
1- function preMain() {
2- setPriceStudy(false);
3- setStudyTitle("Array");
4- setCursorLabelName("Array", 0);
5- setDefaultBarStyle(PS_SOLID, 0);
6- setDefaultBarFgColor(Color.navy, 0);
7- setDefaultBarThickness(1, 0);
8- setPlotType(PLOTTYPE_HISTOGRAM, 0);
}

9- function main() {

10- var vSMq = (getValue("close") - (.5 * (getValue("high") + getValue("low"))));
11- var vEMArN = new ema(20, vSMq);
12- var vEMAsN = new ema(20, vEMArN);

13- return vEMAsN;

}

The problem I have is line 12. When I run the code, the following error comes up:

Line 12; Parameter No. 2 of function ema is invalid

For some reason the EMA does not look at vEMArN and use it to calculate the final result. I believe it may be because vSMq is not in a Series, but I am not sure. If that is the case, how do I get the vSMq into a Series so an EMA() will correctly use it. Or, can I just put my math in line 10 direclty into the first EMA()? I trued that but it does not appear to work.

If anyone has any thoughts, please let me know.

Regards,
ZM

[ACM]

Re: Help with EMA(); Series Needed?

zmendel
The reason you are getting that error message is because your variable vSMq is not a series as required by the ema() function but a value.
In order to create a series that can be used as a source for the ema() function you need to calculate your expression
(getValue("close") - (.5 * (getValue("high") + getValue("low"))));
in a separate function that you then call from the main function using the efsInternal() function (see the link for the description an syntax)
So as the first step create a separate function called [for example] myCalc

function myCalc(){
    return (getValue("Close") - (.5 * (getValue("High") + getValue("Low"))));
} 

At this point in main you use the efsInternal() function to call myCalc and you assign that to your variable vSMq

var vSMq = efsInternal("myCalc"); 

Once you have done that vSMq will be a series which you can then use as the source for the ema() function.
If you search these forums for the keyword efsInternal* you will find many examples of how to use this function to create custom series
Hope this helps
Alex

Originally posted by zmendel
What I want to accomplish is the following:
1- Run the calculation in Line 10 (That works); then,
2- Calculate an EMA of line 10, in line 11; then,
3- Calculate another EMA (double smoothing) in line 12 of line 11; then,
4- Return the results in vEMAsN.

CODE SAMPLE:
1- function preMain() {
2- setPriceStudy(false);
3- setStudyTitle("Array");
4- setCursorLabelName("Array", 0);
5- setDefaultBarStyle(PS_SOLID, 0);
6- setDefaultBarFgColor(Color.navy, 0);
7- setDefaultBarThickness(1, 0);
8- setPlotType(PLOTTYPE_HISTOGRAM, 0);
}

9- function main() {

10- var vSMq = (getValue("close") - (.5 * (getValue("high") + getValue("low"))));
11- var vEMArN = new ema(20, vSMq);
12- var vEMAsN = new ema(20, vEMArN);

13- return vEMAsN;

}

The problem I have is line 12. When I run the code, the following error comes up:

Line 12; Parameter No. 2 of function ema is invalid

For some reason the EMA does not look at vEMArN and use it to calculate the final result. I believe it may be because vSMq is not in a Series, but I am not sure. If that is the case, how do I get the vSMq into a Series so an EMA() will correctly use it. Or, can I just put my math in line 10 direclty into the first EMA()? I trued that but it does not appear to work.

If anyone has any thoughts, please let me know.

Regards,
ZM

[ACM]

zmendel
Adding to my prior reply.
You do not need to use the new operator with the efs2 functions. In your code replace
var vEMArN = new ema(20, vSMq);
var vEMAsN = new ema(20, vEMArN);
in lines 11 and 12 with the following
var vEMArN = ema(20, vSMq);
var vEMAsN = ema(20, vEMArN);
Hope this helps
Alex