EFS questions by shaeffer

[shaeffer]

I've have an EFS, say Bobby.efs that I acquired on the net but it is locked. It is an oscillator in which I compare the current value (bob) and the (-1) value (bob1) as in previous efs discussions here.

I've updated it per our recent discussions to make bob1 global and I've included the null checks. But as the series is created within Bobby.efs (i.e. it is not an eSignal series), I can't define a global series variable or null-check it. Assuming the Bobby.efs calcs are of equivalent complexity to a stochastic calc, will this efs be more likely to be a resource hog because I can't define its series globally? Or does the efsExternal() command define the series equally as well?

Thanks
shaeffer

var bob1   = null;

function main() {

  var bob = efsExternal( "/My Formulas/Bobby.efs" );
   if (getBarState() == BARSTATE_NEWBAR) {
        bob1 = bob.getValue(-1);
    }
    
    if (bob == null || bob1 == null) return; 
..........
--------
return bob;
} 

[shaeffer]

Originally posted by Alexis C. Montenegro
shaeffer
In the for loop you do not need to use setBarBgColor() but only setDefaultBarBgColor()
For the efs2 version of the Stochastic study you need to use both the stochK() and the stochD() functions
Alex

Your barBgColor suggestion makes sense, thanks Alex.

After all your and Jason's help, I think I could fairly quickly add the two global variables to then define the two (Fast and Slow) stochastic series. Would it be an improvement though to the EFS1 method which requires only one series?

Regards
shaeffer

[ACM]

shaeffer
The efsExternal() function creates a series just as if it were one of the built-in study functions.
For your script to work correctly you need to apply the same construct that Jason has shown you earlier in this thread and specifically in the last example in this post.
The only differences will be in the naming of the variables which are going to be xBob, nBob and nBob1 (instead of xHist, nHist, nHist1) and in the line inside the bInit routine where you intialize xBob which will be

if(bInit==false){
    xBob = efsExternal("/myefs.efs");
    bInit=true;
} 

FYI you can find several complete and detailed examples on the use of the efsExternal() function in this and this thread
Alex

Originally posted by shaeffer
I've have an EFS, say Bobby.efs that I acquired on the net but it is locked. It is an oscillator in which I compare the current value (bob) and the (-1) value (bob1) as in previous efs discussions here.

I've updated it per our recent discussions to make bob1 global and I've included the null checks. But as the series is created within Bobby.efs (i.e. it is not an eSignal series), I can't define a global series variable or null-check it. Assuming the Bobby.efs calcs are of equivalent complexity to a stochastic calc, will this efs be more likely to be a resource hog because I can't define its series globally? Or does the efsExternal() command define the series equally as well?

Thanks
shaeffer

var bob1   = null;

function main() {

  var bob = efsExternal( "/My Formulas/Bobby.efs" );
   if (getBarState() == BARSTATE_NEWBAR) {
        bob1 = bob.getValue(-1);
    }
    
    if (bob == null || bob1 == null) return; 
..........
--------
return bob;
} 

[shaeffer]

The previous suggestion to treat the external efs like a built in study worked great, thanks Alex.

But when I tried to apply this efs in a 60 minute timeframe to a 15 minute chart, by inserting inv(60) in the efsExternal line below, I get an error message " Parameter Number 3 of Function getValue is invalid ".

I tried using ....getValue(0, inv(60)) and getValue(-1, inv(60)), but still no luck.

What is the correct way to load this external efs in a 60 minute timeframe for use in other than a 60 minute chart? Then, would the BARSTATE_NEWBAR command act on the 60 minute internal, or the chart interval?

Thank you
shaeffer

var xBob   = null;
var nBob1  = null;
var bInit  = false;

function main() {

    if(bInit==false){
        xBob = efsExternal("/My Formulas/Bobby.efs", inv(60));
        bInit=true;
    }

    var nBob = xBob.getValue(0);  
    if (getBarState() == BARSTATE_NEWBAR) {
        nBob1 = xBob.getValue(-1); 
    }
    
    if (nBob == null || nBob1 == null) return; // 

[ACM]

shaeffer
At this time the efsExternal() function requires at least two parameters in order for the inv() function to control the context in which the external efs is running.
The solution in your case is to add a parameter (for example 0) to use just as a placeholder in the efsExternal() call ie
xBob = efsExternal("/My Formulas/Bobby.efs", 0, inv(60));
Once you implement this change the called efs should run in the context of the interval that is being passed.to it.
It is my understanding that this extra parameter (which is a remnant of the old efs() function) is not documented because it should no longer be required in one of the next releases

Then, would the BARSTATE_NEWBAR command act on the 60 minute internal, or the chart interval?

In this case getBarState() will run in the context of the main interval. Use getBarStateInterval() if you want it to run that section of code in the context of the external interval.
Alex

[shaeffer]

Hello Alex,

I added the extra '0' parameter, and the efs will now load with no Formula Output errors, but all that appears is:
1. Study Title,
2. Brown background

But to get the Brown background, I have to '//' out the null check line, otherwise just the black default Background (pre preMain()) appears.

With the null check commented out, it seems that the 4th condition (nJag < 10) is being seen continuously (hence the brown background). I suspect nJag is getting a null result from the efsExternal call. But if I remove the ...,0,inv(60) from the efsExternal line and allow the null check, it works fine.

So somehow the efsExternal..inv(60) line is still not working, Or have I done something else wrong?

Thank you
shaeffer

function preMain() {
    setStudyTitle("JagC-60");
    setShowTitleParameters( false );
    setShowCursorLabel(false);
    setDefaultBarStyle(PS_SOLID);
    setDefaultBarFgColor(Color.RGB(255,100,30));  // orange
    setDefaultBarThickness(2);
    setPlotType(PLOTTYPE_LINE);
    setDefaultChartBG(Color.black);
}
var color0 = Color.white;
var color1 = Color.cyan;
var xJag   = null;
var nJag1   = null;
var bInit  = false;

function main() {

color1 = color0;

    if(bInit==false){
        xJag = efsExternal("/My Formulas/JagC.efs",0,inv(60));
        //xJag = efsExternal("/My Formulas/JagC.efs");
        bInit=true;
    }

    var nJag = xJag.getValue(0);  
    if (getBarState() == BARSTATE_NEWBAR) {
        nJag1 = xJag.getValue(-1); // retrieve the previous bar's closing number from the xJag series.
    }
    
//   if (nJag == null || nJag1 == null) return; // validate your variables before processing conditions   
    

    if(nJag < 90  &&  nJag1 >= 90  ){                     //Crossed Down thru 90
        color0 = Color.RGB(140,13,80);  //1. Pink
        
    }else if(nJag <= nJag1 && nJag >= 10 && nJag < 90){     //Falling but above 10
        color0 = Color.maroon;          //2. Maroon
        
    }else if(nJag < 10 &&  nJag1 < nJag){                 // Rising uner 10
        color0 = Color.olive;           //5. Olive
        
    }else if(nJag < 10 ){                               //unDer 10
        color0 = Color.RGB(110,50,0);   //3 Brown
        
    }else if(nJag > 10 && nJag1 <= 10){                   //Crossed Up thru 10  
        color0 = Color.blue;           //4. Blue
        
    }else if(nJag > 90  &&  nJag1 > nJag){                  //slope Down above 90
        color0 = Color.RGB(180,70,0);  //1. Orange
        
    }else if(nJag > 90){                                            //Above 90
        color0 = Color.RGB(0,0,100);    //5. Midnight Blue
        
    }else if(nJag > nJag1){                               // Rising but under 90
        color0 = Color.RGB(0,100,45);   //6. Green
        
    }else{
        setChartBG( Color.yellow );                     // a check, should never happen
    }
//---------------------------------------   
    if (color0 != color1){
      setChartBG(color0);
    }    
    
return nJag;
//return;
} 

[ACM]

shaeffer
In order to replicate the problem you will need to provide the efs that is being called
Alex

[shaeffer]

Here is the core efs being called, Alex, but unfortunately it is locked. This core efs in combination with my efs has worked in all time frames when inv(xx) is not used. It has only been when I tried to use these combined efs's in a time interval different from the chart interval that a problem occurred. So hopefully there is not something within the locked efs that prevents its use with inv(xx)

Thanks
shaeffer

[ACM]

shaeffer
The reason it is not working is because the efs that you are calling requires several parameters. You can see this by going in the Edit Studies window for jagc.
So if you want to pass the inv(60) parameter to that efs then you also have to pass ALL the parameters that the efs is expecting in the same order in which they are defined. Your call to the jagc efs should therefore be structured as follows
xJag = efsExternal("/My Formulas/JagC.efs", pds, slw, triggerLen, emaLen, inv(60));
You will need to replace pds, slw, triggerLen and emaLen with the required values. If you do not know in what format these parameters need to be then you will need to contact the author of that script
Alex

[shaeffer]

Good detective work Alex, to look at Edit Studies to find the needed variables. For future reference, will the required variables for an efsExternal call always appear in the Edit Studies list, and in the order they appear in the Edit Studies list?

I will try to find out these parameters from the original efs author.

Regards
shaeffer

[ACM]

shaeffer
In general that is how I [and some others] do it but it may not always be the case.
Alex

[shaeffer]

I think I've determined the correct parameters so that efsExternal call is now working with inv(60). Thank you Alex.