RefUsage2.efs – EFS

RefUsage2.efs

File Name: RefUsage2.efs

Description:
The function, ref(), is used to refer to previously returned values of a formula's indicator. This example formula demonstrates the usage of ref() for formulas that return multiple values or indicators to the chart.

Formula Parameters:

Notes:
The formula uses two basic moving average studies and outputs information to the Formula Output Window. To view the results, open the output window before applying the formula to a chart from the "Tools" menu.

Download File:
RefUsage2.efs

EFS Code:

/***  syntax: ref(nRelativeOffset, nNumBars)   ***

    These examples are based on formulas that return multiple values.  For example:
        return new Array(vValue1, vValue2);
        
    See RefUsage.efs for examples of formulas that return a single values. For example:
        return vValue;
    
    var myRef = ref(-1)     Returns an array of the previous bar's values:
        myRef[0] = vMA1 from -1 bar ago.
        myRef[1] = vMA2 from -1 bar ago.
        
    var myRef = ref(-2, 2)  Returns a two dimentional array of values for bars -2 to -1 bars ago:
        myRef[0][0] = vMA1 from -2 bars ago.
        myRef[0][1] = vMA2 from -2 bars ago.
        myRef[1][0] = vMA1 from -1 bar ago.
        myRef[1][1] = vMA2 from -1 bar ago.
        
    var myRef = ref(-1, -2) Returns a two dimentional array of values for bars -1 to -2 bars ago:
        myRef[0][0] = vMA1 from -1 bar ago.
        myRef[0][1] = vMA2 from -1 bar ago.
        myRef[1][0] = vMA1 from -2 bars ago.
        myRef[1][1] = vMA2 from -2 bars ago.
    
    Note:   VERY IMPORTANT!!
    
            When using ref() it is very important that you incorporate some logic into your
            code that will ensure that ref() returns a valid result.  See the "BarCntr" logic 
            below.  If you don't use the BarCntr logic or some other technique, you will get
            unfavorable results.

 **********************************************/

var study1 = new MAStudy(10, 0, "Close", MAStudy.Simple);
var study2 = new MAStudy(20, 0, "Close", MAStudy.Simple);
 
function preMain() {
    setPriceStudy(true);
}

var BarCntr = 0;
function main() {
    var vMA1 = study1.getValue(MAStudy.MA);
    var vMA2 = study2.getValue(MAStudy.MA);
    
    if (getBarState() == BARSTATE_NEWBAR) {
        BarCntr += 1;
    }

/***  BarCntr logic  ***/
    if (BarCntr > 20) {     // We're using 20 because our longest MAStudy requires a minimum of 20 bars.
    var myRef = ref(-1);
    if (myRef == null) return;
    //var myRef = ref(-2, 2);
    //var myRef = ref(-1, -2);
    var myValue1 = myRef[0];
    var myValue2 = myRef[1];
    }


    // Open the Formula Output Window from the tools menu to view the values of myRef.
    if (BarCntr > 20) {
        debugPrintln("Bar Index: " + getCurrentBarIndex() + "    myValue1= " + myValue1 + "  myValue2= " + myValue2);
    }
    
    return new Array(vMA1, vMA2);
}