2005 June: Something Darvas, Something New

[eSignal_JasonK]

File Name: DarvasBox.efs

Description:
Thus study is based on the June 2005 article, Something Darvas Something New, by Daryl Guppy.

Formula Parameters:
High periods (Bars): Intraday (Default 4)
High periods (Months): DWM (Default 6)

Notes:
The study has options to configure the number of bars required to define the Darvas Box via the Edit Studies option (Chart Options-->Edit Studies). The study is configured for daily or intraday intervals. For daily charts, the formula only uses the second parameter ( "High Periods(Months): DWM" )and is based on monthly highs. The default is set to look for a 6 month high. The chart example provided is using a 1-month high. For intraday charts, the formula uses the first parameter, which is based on the specified number of bars for the chart's interval. On intraday charts the study will also give audible alerts when a bar closes above or below a Darvas Box or below a Ghost Box. The Darvas and Ghost boxes appear in blue and green, respectively. The related article is copyrighted material. If you are not a subscriber of Stocks & Commodities, please visit www.traders.com.

Download File:
DarvasBox.efs



EFS Code:

/***************************************
Provided By : eSignal (c) Copyright 2005
Description:  Darvas Box

Version 1.0  4/12/2005

Notes:
June 2005 Issue - "Something Darvas, Something New" 
    by Daryl Guppy
    
This study uses EFS2 functionality available in eSignal
version 7.9 or later.

Formula Parameters:                 Defaults:
High periods (Bars): Intraday       4
High periods (Months): DWM          6
***************************************/

function preMain() {
    setPriceStudy(true);
    setStudyTitle("Darvas Box ");
    setShowTitleParameters(false);
    setCursorLabelName("Darvas High", 0);
    setCursorLabelName("Darvas Low", 1);
    setDefaultBarFgColor(Color.blue, 0);
    setDefaultBarFgColor(Color.blue, 1);
    setDefaultBarThickness(2, 0);    
    setDefaultBarThickness(2, 1);    
    setPlotType(PLOTTYPE_FLATLINES, 0);
    setPlotType(PLOTTYPE_FLATLINES, 1);
    
    // Number of bars to define Darvas Box High on intraday intervals.
    var fp1 = new FunctionParameter("iLength", FunctionParameter.NUMBER);
        fp1.setName("High periods (Bars): Intraday");
        fp1.setLowerLimit(1);
        fp1.setDefault(4);
    // Number of Monthly bars to define a Darvas Box High on D,W,M intervals.
    var fp2 = new FunctionParameter("dLength", FunctionParameter.NUMBER);
        fp2.setName("High periods (Months): DWM");
        fp2.setLowerLimit(1);
        fp2.setDefault(6);
}

var bVersion = null;
var dh = null;      // Darvas High
var dl = null;      // Darvas Low
var bBox = false;   // Darvas Box exists
var gBox = false;   // Ghost Box
var gBoxHeight = 0; // Ghost Box Height
var gBoxLength = 0; // Ghost Box Length
var gBoxCntr = 0;   // Current Ghost Box Length
var gBoxNum = 0;    // Ghost Box number.
var gBoxBase = 0 ;  // Base start value for bottom of Ghost Box.
var bDraw = false;  // Allow new Ghost Box to be drawn.
var CurIndex = null;// Current Bar Index;
var CurIndex1 = null;
var nCntr = 0;      // Number of bars to start a box
var nBoxCntr = 0;
var nIndex = 0;     // Bar index of start of last box

function main(iLength, dLength) {
    if (bVersion == null) bVersion = verify();
    if (bVersion == false) return;
    var nState = getBarState();
    
    if (nState == BARSTATE_NEWBAR) {
        CurIndex1 = CurIndex;
        if (bBox == true) adjustIndex();
        nCntr++;
    }
    
    CurIndex = getCurrentBarIndex();
    if (CurIndex1 == null) return;

    // New Darvas Box
    if (bBox == false && nState == BARSTATE_NEWBAR && nCntr >= 4) {
        var bSetdh = false;
        if (dh == null || high(0) > dh) {  // set dh
            var h = high(-4);
            var nTestHigh = testHigh(iLength, dLength);
            if (high(-1) < h && high(-2) < h && high(-3) < h && h >= nTestHigh) {
                dh = h;
                bSetdh = true;
                nIndex = CurIndex - 4;  // bar index of dh                
            }
        } 
        if (dl == null && dh != null) { // set dl
            for (var i = nIndex; i < getCurrentBarIndex()-3; i++) {
                var index = i-getCurrentBarIndex();
                var l = low(index);
                if (low(index+1) > l && low(index+2) > l && low(index+3) > l) {
                    dl = l;
                    i = 0;
                }
            }
            if (dl == null && bSetdh == false) adjustIndex();
        }
        if (dh != null && dl != null) {  // Darvas Box found
            if (bSetdh == false && (CurIndex - CurIndex1) == 0) adjustIndex();
            bBox = true;
            removeGhostBox(gBoxNum);
            gBox = false;
            nBoxCntr++;
            var aBox = new Array(dh, dl);
            var i = getCurrentBarIndex()-1;
            var j = -1;
            while (i >= nIndex) {  // plot box back to the dh bar index.
                setBar(Bar.Value, j, aBox);
                j--;
                i--;
            }
            // New D_Box range has formed.
            Alert.playSound("Blip.wav");
            drawLineRelative(j+1, dh, j+1, dl, PS_SOLID, 2, Color.blue, "left"+nBoxCntr);
        } 
    }
    
    // Check for breach of Darvas Box
    if (nState == BARSTATE_NEWBAR && bBox == true) {
        if (close(-1) > dh) {
            // Entry Trigger: Bar closed above top of D_Box
            Alert.playSound("beam1.wav");
            gBox = true; // Draw Ghost Box
            gBoxHeight = dh - dl;
            gBoxLength = (CurIndex -nIndex) -1;
            gBoxBase = dh;
            gBoxNum++;
            gBoxCntr = 0;
            bDraw = true;
            drawGhostBox();
        } else if (close(-1) < dl) {
            // Exit Trigger: Bar closed below D_Box
            Alert.playSound("buzz.wav");
        }
        if (close(-1) > dh || close(-1) < dl) {  // reset globals to find next box.
            bBox = false;
            drawLineRelative(-1, dh, -1, dl, PS_SOLID, 2, Color.blue, "right"+nBoxCntr);
            dh = null;
            dl = null;
            nIndex = 0;
            nCntr = 0;
        }
    }

    if (gBox == true && nState == BARSTATE_NEWBAR) drawGhostBox();

    if (dh == null || dl == null) {
        return new Array(null, null);
    } else {
        return new Array(dh, dl);
    }
}



/***** Support Functions *****/

function removeGhostBox(num) {
    //if (gBox == true) {
        removeLine("gBoxLeft"+num);
        removeLine("gBoxRight"+num);
        removeLine("gBoxTop"+num);
        removeLine("gBoxBottom"+num);
    //}
    return;
}

function drawGhostBox() {
    if (close(-1) < gBoxBase) {
        // Exit Trigger:  Bar closed below G_Box
        Alert.playSound("buzz.wav");
        gBox = false;
        return;
    }
    if (gBoxCntr > gBoxLength) {
        gBoxBase += gBoxHeight;
        gBoxCntr = 0;
        gBoxNum++;
        bDraw = true;
    }
    gBoxCntr++;

    if (bDraw == true) {
        drawLineRelative(-1, gBoxBase, -1, gBoxBase+gBoxHeight, PS_SOLID, 3, Color.RGB(45, 185, 45), "gBoxLeft"+gBoxNum);
        drawLineRelative(-1+gBoxLength, gBoxBase, -1+gBoxLength, gBoxBase+gBoxHeight, PS_SOLID, 3, Color.RGB(45, 185, 45), "gBoxRight"+gBoxNum);
        drawLineRelative(-1, gBoxBase+gBoxHeight, -1+gBoxLength, gBoxBase+gBoxHeight, PS_SOLID, 3, Color.RGB(45, 185, 45), "gBoxTop"+gBoxNum);
        drawLineRelative(-1, gBoxBase, -1+gBoxLength, gBoxBase, PS_SOLID, 3, Color.RGB(45, 185, 45), "gBoxBottom"+gBoxNum);
        bDraw = false;
    }
    
    return;
}

function testHigh(i, d) {
    var nH = null;  
    var aH;
    if (isDWM()) {
        nH = high(0, inv("M"));
        for (var j = 1; j < d; j++) {
            nH = Math.max(nH, high(-j, inv("M")));
        }
    } else {
        nH = high(-5);
        for (var j = i-1; j > 0; j--) {
            nH = Math.max(nH, high(-j-5));
        }
    }    
    
    return nH;
}

function adjustIndex() {
    if (isComputeOnClose() && getCurrentBarIndex() == -1) {
        nIndex--;
    } else if (getCurrentBarIndex() == 0) {
        nIndex--;
    }
    return;
}

function verify() {
    var b = false;
    if (getBuildNumber() < 700) {
        drawTextRelative(65, 35, "This study requires version 7.9 or later.", 
            Color.white, Color.blue, Text.BOLD|Text.LEFT|Text.RELATIVETOLEFT|Text.RELATIVETOBOTTOM,
            null, 14, "error");
        drawTextRelative(65, 20, "Click HERE to upgrade.@URL=http://www.esignal.com/download/default.asp", 
            Color.white, Color.blue, Text.BOLD|Text.LEFT|Text.RELATIVETOLEFT|Text.RELATIVETOBOTTOM,
            null, 14, "upgrade");
        return b;
    } else {
        b = true;
    }
    
    return b;
}