Polarized Fractal Efficiency Modification Request

[fmanu1]

Hi all, I'm a new eSignal user, but not new to trading. I'm moving over my indicators from my current software platform, but I'm having difficulty with one of them. This is the PFE indicator originally developed by Hans Hannula.

I like this indicator; I find it to be a very useful indicator in providing me with clues about what the market is doing. However, I find the eSignal efs version of it (which can be found here in the forum ) to be limited.

I know very little about javascript; I have been able to go into it and modify the length, but the code from my broker contains an additional input for smoothing length... here is their version in its entirety:

declare lower;

input length = 10;
input smoothingLength = 5;

def diff = close - close[length - 1];
def val = 100 * Sqrt(Sqr(diff) + Sqr(length)) / sum(Sqrt(1 + Sqr(close - close[1])), length - 1);

plot PFE = ExpAverage(if diff > 0 then val else -val, smoothingLength);
plot UpperLevel = 50;
plot ZeroLine = 0;
plot LowerLevel = -50;

PFE.SetDefaultColor(GetColor(8)); UpperLevel.SetDefaultColor(GetColor(5)); ZeroLine.SetDefaultColor(GetColor(5)); LowerLevel.SetDefaultColor(GetColor(5));

Would someone help me modify the PFE.efs file to include a smoothing length and two inputs that I can change without having to go into the efs file - one for length and the other for smoothing length?

Any help would be greatly appreciated.

[ACM]

Re: Polarized Fractal Efficiency Modification Request

fmanu1
The efs you referenced actually uses both parameters except that they were not set to be user definable.
To add that functionality is relatively simple.
As a first step add the following lines of code in the preMain function

var fp1 = new FunctionParameter("Length", FunctionParameter.NUMBER);
 fp1.setDefault(10); 
 
 var fp2 = new FunctionParameter("Smoothing", FunctionParameter.NUMBER);
 fp2.setDefault(5); 

These use the FunctionParameter Object to create user definable parameters (see the link to the corresponding article in the EFS KnowledgeBase for more information and other examples)
Now you need to add these parameters to the arguments of the main function eg

function main(Length, Smoothing) { 

Once you have done that you need to add the Length parameter in the efsInternal() call so as to pass it to the corresponding function eg

xFracEff = efsInternal("Calc_FracEff", Length); 

Then replace the 5 with Smoothing in the line of code where the ema is initialized eg

xEMA = ema(Smoothing, xFracEff) 

Now you also need to add the Length parameter to the arguments of the CalcFracEff function eg

function Calc_FracEff(Length){ 

At this point you need to replace close(-9) with close(-(Length-1)) in lines 65 and 69 of the original formula eg

PFE = Math.sqrt(Math.pow((close(0) - close(-(Length-1))),2) + 100);
//and
if ((close(0) - close(-(Length-1))) > 0) FracEff = Math.round((PFE / C2C) * 100); 

and replace Counter < 10 with Counter < Length in line 66 eg

for (Counter = 1; Counter < Length; Counter++)    { 

Once you have implemented these changes save the efs with a new name so as not to overwrite the original.
Then load the efs and you should be able to adjust the Length and Smoothing parameters from Edit Studies
If you are unfamiliar with programming in efs and are interested in learning then I would suggest that you begin by reviewing the JavaScript for EFS video series and the Core JavaScript Reference Guide. Those will provide you with a thorough introduction to programming in JavaScript which is at the foundation of EFS. Then go through the EFS KnowledgeBase and study the Help Guides and Tutorials which will provide you with the specifics of EFS.
Alex

Originally posted by fmanu1
Hi all, I'm a new eSignal user, but not new to trading. I'm moving over my indicators from my current software platform, but I'm having difficulty with one of them. This is the PFE indicator originally developed by Hans Hannula.

I like this indicator; I find it to be a very useful indicator in providing me with clues about what the market is doing. However, I find the eSignal efs version of it (which can be found here in the forum ) to be limited.

I know very little about javascript; I have been able to go into it and modify the length, but the code from my broker contains an additional input for smoothing length... here is their version in its entirety:



Would someone help me modify the PFE.efs file to include a smoothing length and two inputs that I can change without having to go into the efs file - one for length and the other for smoothing length?

Any help would be greatly appreciated.

[fmanu1]

Thanks for the help, Alex. Unfortunately, I think I made a mistake. When I tried to do a syntax check I got an error saying that I was missing a } after the function body, which is right at the end of the code, but I wasn't able to correct this.

This is the code based upon what I could figure out.

Formula Parameters: 
Default: **********************************/

  var bInit = false;  function preMain() {     setStudyTitle("Polarized Fractal Efficiency");     
setCursorLabelName("EMA", 0);     
setDefaultBarFgColor(Color.aqua, 0);      
addBand(50, PS_SOLID, 1, Color.blue);         
addBand(-50, PS_SOLID, 1, Color.red);            
var fp1 = new FunctionParameter("Length", FunctionParameter.NUMBER);
 fp1.setDefault(10);       
var fp2 = new FunctionParameter("Smoothing", FunctionParameter.NUMBER);   fp2.setDefault(5);   }  
var xEMA = null; var xFracEff = null;   
function main() { var nBarState = getBarState(); 
var nEMA = 0;         
if ( bInit == false ) {          xFracEff = efsInternal("Calc_FracEff", Length);         
xEMA = ema(Smoothing, xFracEff)         bInit = true;      }       
nEMA = xEMA.getValue(0);     
if (nEMA == null) return;          
return nEMA;     
function main(Length, Smoothing) { }   function Calc_FracEff(Length){ var PFE = 0; var C2C = 0; 
var Counter = 0; 
var FracEff = 0;     
PFE = Math.sqrt(Math.pow((close(0) - close(-(Length-1))),2) + 100);      
for (Counter = 1; Counter < Length; Counter++)    {         C2C += Math.sqrt(Math.pow((close(-Counter + 1) - close(-Counter)), 2) + 1);     }     
if ((close(0) - close(-(Length-1))) > 0) FracEff = Math.round((PFE / C2C) * 100);     
else FracEff = Math.round(-(PFE / C2C) * 100);     if (FracEff == null) FracEff = 1;     return FracEff; } 

Can you help me clarify my mistake?

Thanks

[fmanu1]

While I wasn't able to get the code right, I was able to figure out what the smoothing length was. I've created a couple of different instances of the indicator. That's all I need, since I only use a coupe of different settings. I appreciate the help.

[ACM]

fmanu1
Enclosed below is the corrected version of your revision so that you can compare them
Alex

var bInit = false;
function preMain() {
    setStudyTitle("Polarized Fractal Efficiency");
    setCursorLabelName("EMA", 0);
    setDefaultBarFgColor(Color.aqua, 0);
    addBand(50, PS_SOLID, 1, Color.blue);
    addBand( - 50, PS_SOLID, 1, Color.red);
    var fp1 = new FunctionParameter("Length", FunctionParameter.NUMBER);
    fp1.setDefault(10);
    var fp2 = new FunctionParameter("Smoothing", FunctionParameter.NUMBER);
    fp2.setDefault(5);
}
var xEMA = null;
var xFracEff = null;
function main(Length, Smoothing) {
    var nBarState = getBarState();
    var nEMA = 0;
    if (bInit == false) {
        xFracEff = efsInternal("Calc_FracEff", Length);
        xEMA = ema(Smoothing, xFracEff) ;
        bInit = true;
    }
    nEMA = xEMA.getValue(0);
    if (nEMA == null) return;
    return nEMA;
}
function Calc_FracEff(Length) {
    var PFE = 0;
    var C2C = 0;
    var Counter = 0;
    var FracEff = 0;
    PFE = Math.sqrt(Math.pow((close(0) - close( - (Length - 1))), 2) + 100);
    for (Counter = 1; Counter < Length; Counter++) {
        C2C += Math.sqrt(Math.pow((close( - Counter + 1) - close( - Counter)), 2) + 1);
    }
    if ((close(0) - close( - (Length - 1))) > 0) FracEff = Math.round((PFE / C2C) * 100);
    else FracEff = Math.round( - (PFE / C2C) * 100);
    if (FracEff == null) FracEff = 1;
    return FracEff;
} 

Originally posted by fmanu1
Thanks for the help, Alex. Unfortunately, I think I made a mistake. When I tried to do a syntax check I got an error saying that I was missing a } after the function body, which is right at the end of the code, but I wasn't able to correct this.

This is the code based upon what I could figure out.

Formula Parameters: 
Default: **********************************/

  var bInit = false;  function preMain() {     setStudyTitle("Polarized Fractal Efficiency");     
setCursorLabelName("EMA", 0);     
setDefaultBarFgColor(Color.aqua, 0);      
addBand(50, PS_SOLID, 1, Color.blue);         
addBand(-50, PS_SOLID, 1, Color.red);            
var fp1 = new FunctionParameter("Length", FunctionParameter.NUMBER);
 fp1.setDefault(10);       
var fp2 = new FunctionParameter("Smoothing", FunctionParameter.NUMBER);   fp2.setDefault(5);   }  
var xEMA = null; var xFracEff = null;   
function main() { var nBarState = getBarState(); 
var nEMA = 0;         
if ( bInit == false ) {          xFracEff = efsInternal("Calc_FracEff", Length);         
xEMA = ema(Smoothing, xFracEff)         bInit = true;      }       
nEMA = xEMA.getValue(0);     
if (nEMA == null) return;          
return nEMA;     
function main(Length, Smoothing) { }   function Calc_FracEff(Length){ var PFE = 0; var C2C = 0; 
var Counter = 0; 
var FracEff = 0;     
PFE = Math.sqrt(Math.pow((close(0) - close(-(Length-1))),2) + 100);      
for (Counter = 1; Counter < Length; Counter++)    {         C2C += Math.sqrt(Math.pow((close(-Counter + 1) - close(-Counter)), 2) + 1);     }     
if ((close(0) - close(-(Length-1))) > 0) FracEff = Math.round((PFE / C2C) * 100);     
else FracEff = Math.round(-(PFE / C2C) * 100);     if (FracEff == null) FracEff = 1;     return FracEff; } 

Can you help me clarify my mistake?

Thanks

[fmanu1]

Excellent! Yes that pretty much captures what it does and the variable length inputs are convenient too. Thanks again for the help and here is a EFS file of it.

[ACM]

fmanu1
You are most welcome
Alex

Originally posted by fmanu1
Excellent! Yes that pretty much captures what it does and the variable length inputs are convenient too. Thanks again for the help and here is a EFS file of it.