Zerolag ema

[opstock]

I really like the zero lag ema and I'm trying to use it with some condition statements, but it doesn't follow the conditions. It just seems to randomly plot. I wrote a simple conditional statement to setBarBgcolor if the high(-3) < the zerolag && the current bar low(0) > the zerolag, but as I said, it seems to just plot randomly. Could someone take a look at this and tell me what I need to do, or point me in the right direction. Thanks!

/*********************************
Provided By:
eSignal (Copyright © eSignal), a division of Interactive Data
Corporation. 2007. All rights reserved. This sample eSignal
Formula Script (EFS) is for educational purposes only and may be
modified and saved under a new file name. eSignal is not responsible
for the functionality once modified. eSignal reserves the right
to modify and overwrite this EFS file with each new release.

Description: Trading Divergences
by Sylvain Vervoort

Version: 1.0 12/7/2007

Notes:
* February 2008 Issue of Stocks and Commodities Magazine
* Study requires version 8.0 or later.

Formula Parameters: Defaults:
Periods 20
**********************************/


function preMain() {
setPriceStudy(true);
setStudyTitle("Zero Lag EMA test");
setCursorLabelName("ZEMA", 0);
setDefaultBarFgColor(Color.white, 0);
setDefaultBarThickness(2, 0);

var fp1 = new FunctionParameter("nPeriods", FunctionParameter.NUMBER);
fp1.setName("Periods");
fp1.setLowerLimit(1);
fp1.setDefault(13);
}

// Global Variables
var bVersion = null; // Version flag
var bInit = false; // Initialization flag

var xEma1 = null;
var xEma2 = null;

function main(nPeriods) {
var nState = getBarState();
var nIndex = getCurrentBarIndex();
if (bVersion == null) bVersion = verify();
if (bVersion == false) return;


if (bInit == false) {
xEma1 = ema(nPeriods);
xEma2 = ema(nPeriods, xEma1);
bInit = true;
}

var nZEma = null;
var nEma1 = xEma1.getValue(0);
var nEma2 = xEma2.getValue(0);
if (nEma1 == null || nEma2 == null) return;

nZEma = nEma1 + (nEma1 - nEma2);

if(high(-3) < nZEma &&
low(0) > nZEma) {
setBarBgColor(Color.RGB(123,103,0));
}



return nZEma;
}


function verify() {
var b = false;
if (getBuildNumber() < 779) {
drawTextAbsolute(5, 35, "This study requires version 8.0 or later.",
Color.white, Color.blue, Text.RELATIVETOBOTTOM|Text.RELATIVETOLEFT|Text.BOL D|Text.LEFT,
null, 13, "error");
drawTextAbsolute(5, 20, "Click HERE to upgrade.@URL=http://www.esignal.com/download/default.asp",
Color.white, Color.blue, Text.RELATIVETOBOTTOM|Text.RELATIVETOLEFT|Text.BOL D|Text.LEFT,
null, 13, "upgrade");
return b;
} else {
b = true;
}

return b;
}

[ACM]

Re: Zerolag ema

opstock
As far as I can see it is actually following the conditions ie it colors the background of the current bar if the high of three bars ago is less than the current value of the zerolag ma and if the low of the current bar is greater than the current value of the zerolag ma
Perhaps you want the high of three bars ago to be below the zerolag ma of three bars ago.
In that case you could use the ref() function to retrieve the value of the zerolag ma of three bars ago and then use that in your condition.
For the description and syntax of the ref() function see this article in the EFS KnowledgeBase. You can also find a practical example of the use of the ref() function in this article also in the EFS KnowledgeBase
Alex

Originally posted by opstock
I really like the zero lag ema and I'm trying to use it with some condition statements, but it doesn't follow the conditions. It just seems to randomly plot. I wrote a simple conditional statement to setBarBgcolor if the high(-3) < the zerolag && the current bar low(0) > the zerolag, but as I said, it seems to just plot randomly. Could someone take a look at this and tell me what I need to do, or point me in the right direction. Thanks!

/*********************************
Provided By:
eSignal (Copyright © eSignal), a division of Interactive Data
Corporation. 2007. All rights reserved. This sample eSignal
Formula Script (EFS) is for educational purposes only and may be
modified and saved under a new file name. eSignal is not responsible
for the functionality once modified. eSignal reserves the right
to modify and overwrite this EFS file with each new release.

Description: Trading Divergences
by Sylvain Vervoort

Version: 1.0 12/7/2007

Notes:
* February 2008 Issue of Stocks and Commodities Magazine
* Study requires version 8.0 or later.

Formula Parameters: Defaults:
Periods 20
**********************************/


function preMain() {
setPriceStudy(true);
setStudyTitle("Zero Lag EMA test");
setCursorLabelName("ZEMA", 0);
setDefaultBarFgColor(Color.white, 0);
setDefaultBarThickness(2, 0);

var fp1 = new FunctionParameter("nPeriods", FunctionParameter.NUMBER);
fp1.setName("Periods");
fp1.setLowerLimit(1);
fp1.setDefault(13);
}

// Global Variables
var bVersion = null; // Version flag
var bInit = false; // Initialization flag

var xEma1 = null;
var xEma2 = null;

function main(nPeriods) {
var nState = getBarState();
var nIndex = getCurrentBarIndex();
if (bVersion == null) bVersion = verify();
if (bVersion == false) return;


if (bInit == false) {
xEma1 = ema(nPeriods);
xEma2 = ema(nPeriods, xEma1);
bInit = true;
}

var nZEma = null;
var nEma1 = xEma1.getValue(0);
var nEma2 = xEma2.getValue(0);
if (nEma1 == null || nEma2 == null) return;

nZEma = nEma1 + (nEma1 - nEma2);

if(high(-3) < nZEma &&
low(0) > nZEma) {
setBarBgColor(Color.RGB(123,103,0));
}



return nZEma;
}


function verify() {
var b = false;
if (getBuildNumber() < 779) {
drawTextAbsolute(5, 35, "This study requires version 8.0 or later.",
Color.white, Color.blue, Text.RELATIVETOBOTTOM|Text.RELATIVETOLEFT|Text.BOL D|Text.LEFT,
null, 13, "error");
drawTextAbsolute(5, 20, "Click HERE to upgrade.@URL=http://www.esignal.com/download/default.asp",
Color.white, Color.blue, Text.RELATIVETOBOTTOM|Text.RELATIVETOLEFT|Text.BOL D|Text.LEFT,
null, 13, "upgrade");
return b;
} else {
b = true;
}

return b;
}

[opstock]

Oh my! I'm such an idiot. I forgot to put in -3 for the nZEma, duh!. Thanks for the quick response Alex.

[ACM]

opstock
Using -3 as is will not work because the variable nZEma is not a series [hence it does not contain historical values] which is why I said you will need to retrieve the value of the zerolag ma of three bars ago using the ref() function
Alex

Originally posted by opstock
Oh my! I'm such an idiot. I forgot to put in -3 for the nZEma, duh!. Thanks for the quick response Alex.

[opstock]

Yes, thanks so much Alex. I figured it out using the references you gave me and it works perfectly.

[ACM]

opstock
You are most welcome
Alex

Originally posted by opstock
Yes, thanks so much Alex. I figured it out using the references you gave me and it works perfectly.