Trend Lines – EFS

TrendLines.efs
EFSLibrary - Discussion Board
File Name: TrendLines.efs
Description:
Trend Lines
Formula Parameters:
Length : 10
Notes:
Download File:
TrendLines.efs

EFS Code:
/*********************************
Provided By:  
    eSignal (Copyright c eSignal), a division of Interactive Data 
    Corporation. 2009. 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:        
    Trend Lines
Version:            1.0  09/14/2009
 
Formula Parameters:                     Default:
    Length                              10
   
Notes:
    
**********************************/
var fpArray = new Array();
var bInit = false;

function preMain(){
    setPriceStudy(true);
    setShowCursorLabel(false);
    setShowTitleParameters(false);
    setStudyTitle("Trend Lines");
    var x = 0;
    fpArray[x] = new FunctionParameter("Length", FunctionParameter.NUMBER);
    with(fpArray[x++]) {
        setName("Length");
        setLowerLimit(1);
        setDefault(10);
    }    
}

var xLowest = null;
var xHighest = null;
var r1 = 0;
var r2 = 0;
var rt1 = 0;
var rt2 = 0;
var s1 = 0;
var s2 = 0;
var st1 = 0;
var st2 = 0;

function main(Length) {
var nBarState = getBarState();
var nPos = 0;    
var X, X1, X2, Y1, Y2, K;
    if (nBarState == BARSTATE_ALLBARS) {
        if(Length == null) Length = 10;
	}
	if (bInit == false) {
        xHighest = highest(Length, high());
        xLowest = lowest(Length, low());
        bInit = true;
	}
    if (xLowest.getValue(-nPos) == null || xHighest.getValue(-nPos) == null) return;
	nPos = Math.round((Length - 1)/2);    
    if(low(-nPos) == xLowest.getValue(-1) && ((getCurrentBarCount() - nPos) - st1) >= nPos)  {
        s2 = s1; 
        s1 = low(-nPos);
        st2 = st1; 
        st1 = getCurrentBarCount() - nPos;
    }
    if(high(-nPos) == xHighest.getValue(-1) && ((getCurrentBarCount() - nPos) - rt1) >= nPos) {
        r2=r1; 
        r1 = high(-nPos);
        rt2 = rt1; 
        rt1 = getCurrentBarCount() - nPos;
    }
    X1 = -(getCurrentBarCount() - st2);
    X2 = -(getCurrentBarCount() - st1);
    Y1 = s2;
    Y2 = s1;
    K = (Y2-Y1) / (X2-X1);
    X2 = X2 - Math.round(X1 / 2)  + Length;
    Y2 = Y1 + K * (X2-X1); 
    drawLineRelative(-(getCurrentBarCount() - st2), s2, X2, Y2, PS_SOLID, 2, Color.green, "Down"); 
    X1 = -(getCurrentBarCount() - rt2);
    X2 = -(getCurrentBarCount() - rt1);
    Y1 = r2;
    Y2 = r1;
    K = (Y2-Y1) / (X2-X1);
    X2 = X2 - Math.round(X1 / 2)  + 10;
    Y2 = Y1 + K * (X2-X1); 
    drawLineRelative(-(getCurrentBarCount() - rt2), r2, X2, Y2, PS_SOLID, 2, Color.red, "Up");             
    return;
}