Need Previous StochD Value

[alexmihh]

I have an efs that tracks the StochD values on various futures. I am sure I got this code from the forum, and it works swell.

But I want to grab also the previous value of StochD and do a comparison, and I do not know how to get that previous value with the code as it is girven below.

I think it s more complicated than simply using a (-1) somewhere (where?, how?)

/****************************************************************************************************
7:00 pm    20NNOV06            STochD-US.efs   
*****************************************************************************************************
latest fix:
to do: 

*****************************************************************************************************/
var DOWiSymbol = null;
var RUSiSymbol = null;
var iIntervalLO = null;
var bALERTON = false;
var DOWValue = null;
var RUSValue = null;
var bDOWOFF = false;
var bRUSOFF = false;
var vHI = 65;
var vLO = 35;

function preMain() {

    setPriceStudy(true);
    setStudyTitle("DOW SCANNER"); 
//    setComputeOnClose();


    DOWiSymbol = new FunctionParameter("DOWiSymbol", FunctionParameter.STRING);
        DOWiSymbol.setDefault( "YM #F" );

    RUSiSymbol = new FunctionParameter("RUSiSymbol", FunctionParameter.STRING);
        RUSiSymbol.setDefault( "AB #F" );

    iIntervalLO = new FunctionParameter("iIntervalLO", FunctionParameter.NUMBER);
    iIntervalLO.setDefault( 1 ); 



}
  

function main(DOWiSymbol, RUSiSymbol, iIntervalLO ){

  if (!bDOWOFF) {
    DOWValue = ( stochD(5,5,6,sym(DOWiSymbol + "," + iIntervalLO))  ).toFixed(0);
    if (DOWValue >= vHI) {
        drawTextAbsolute(5, 197, " DOW = " + DOWValue + " " + "@URL=EFS:DOWOFF", Color.RGB(255,255,0), Color.red, 
                        Text.LEFT |  Text.RELATIVETOLEFT | Text.RELATIVETOTOP | Text.BOLD, null, 11, "DOW" );
    }

    if (DOWValue <= vLO) {
        drawTextAbsolute(5, 197, " DOW = " + DOWValue + " " + "@URL=EFS:DOWOFF", Color.RGB(255,255,0), Color.green, 
                        Text.LEFT |  Text.RELATIVETOLEFT | Text.RELATIVETOTOP | Text.BOLD, null, 11, "DOW" );
    }

    if (DOWValue > vLO && DOWValue < vHI) {
//        drawTextAbsolute(1, 137, " DOW = " + DOWValue + " " + "@URL=EFS:DOWOFF", Color.RGB(255,255,0), Color.blue, 
//                        Text.LEFT |  Text.RELATIVETOLEFT | Text.RELATIVETOTOP | Text.BOLD, null, 11, "DOW" );
//        bDOWOFF = false;
        removeText("DOW");
    }
  }



  if (!bRUSOFF) {
    RUSValue = ( stochD(5,5,6,sym(RUSiSymbol + "," + iIntervalLO))  ).toFixed(0);
    if (RUSValue >= vHI) {
        drawTextAbsolute(5, 217, " RUS = " + RUSValue + " " + "@URL=EFS:RUSOFF", Color.RGB(255,255,0), Color.red, 
                        Text.LEFT |  Text.RELATIVETOLEFT | Text.RELATIVETOTOP | Text.BOLD, null, 11, "RUS" );
    }

    if (RUSValue <= vLO) {
        drawTextAbsolute(5, 217, " RUS = " + RUSValue + " " + "@URL=EFS:RUSOFF", Color.RGB(255,255,0), Color.green, 
                        Text.LEFT |  Text.RELATIVETOLEFT | Text.RELATIVETOTOP | Text.BOLD, null, 11, "RUS" );
    }

    if (RUSValue > vLO && RUSValue < vHI) {
//        drawTextAbsolute(10, 137, " RUS = " + RUSValue + " " + "@URL=EFS:RUSOFF", Color.RGB(255,255,0), Color.blue, 
//                        Text.LEFT |  Text.RELATIVETOLEFT | Text.RELATIVETOTOP | Text.BOLD, null, 11, "RUS" );
//        bRUSOFF = false;
        removeText("RUS");
    }
  }



//

}        // end MAIN 

[ACM]

alexmihh
Because in these two lines

DOWValue = ( stochD(5,5,6,sym(DOWiSymbol + "," + iIntervalLO))  ).toFixed(0);
//and
RUSValue = ( stochD(5,5,6,sym(RUSiSymbol + "," + iIntervalLO))  ).toFixed(0); 

you are using the .toFixed() method when intializing the study the formula engine is retrieving the current value of the study and converting it to a string. Hence DOWValue is no longer a series which means that you cannot retrieve any of its values using the .getValue() method.
The way to resolve this is to remove the .toFixed() from both those lines then run a null check on the values eg
if(DOWValue.getValue(0)==null) return;
and then apply the toFixed() method to the value inside the drawText command (see example enclosed below).
Once you implement these changes you will then be able to use the .getValue() method to retrieve the values of the series (eg DOWValue.getValue(-1), etc)
Alex

if (!bDOWOFF) {
    DOWValue = stochD(5,5,6,sym(DOWiSymbol + "," + iIntervalLO));
    if(DOWValue.getValue(0)==null) return;
    if (DOWValue.getValue(0) >= vHI) {
        drawTextAbsolute(5, 197, " DOW = " + DOWValue.getValue(0).toFixed(0) + " " + "@URL=EFS:DOWOFF", Color.RGB(255,255,0), Color.red, 
                        Text.LEFT |  Text.RELATIVETOLEFT | Text.RELATIVETOTOP | Text.BOLD, null, 11, "DOW" );
    }
    if (DOWValue.getValue(0)<= vLO) {
        drawTextAbsolute(5, 197, " DOW = " + DOWValue.getValue(0).toFixed(0) + " " + "@URL=EFS:DOWOFF", Color.RGB(255,255,0), Color.green, 
                        Text.LEFT |  Text.RELATIVETOLEFT | Text.RELATIVETOTOP | Text.BOLD, null, 11, "DOW" );
    }
    if (DOWValue.getValue(0) > vLO && DOWValue.getValue(0) < vHI) {
        removeText("DOW");
    }
} 

[alexmihh]

Thank you so kindly.

I have implementated your changes, made a few enhancements, and now have a great working EFS

I have a question. What is the purpose of this statement? What does it do? Why is it needed? Etc

if(DOWValue.getValue(0)==null) return;

[ACM]

alexmihh
You are most welcome.
That conditional statement is a null check to ensure that the variable contains valid data before we access any of its properties. Otherwise when you use the toFixed() method you will get an error stating the the variable has no properties. This is because in the first n bars the study is returning null while it is priming.
Alex