Slope Trend Indicator

[maxmax68]

I am not a pro, so I don't know if it already exists and its real name !!!
I thought about a surrogate for Linear Regression, easy to calculate, that I called "Trend Slope Indicator" for obvious reasons .
Although this indicator is extremely trivial, I find it useful as a filter within trading systems to prevent trades during non-trendy market, for example by avoiding operations where its value is less than 0.5.
When it has high values, for example greater than 2, it indicates that we are in a trendy market and it is better to approach the trailing stop because there could be a reversal.
So it's a simple indicator of trend. Remember to set the tick properly.
Passing correctly the parameters can be used as a efsExternal.
Let me Know if you find other interesting ways to use it.
Regards
Massimo

/************************************************** ********************
SLOPE TREND INDICATOR by Massimo Rizzi ([email protected]) May 2011
I used as a sample an EFS 2 Custom provided by ESignal !
Use and/or modify this code freely. If you redistribute it
please include this and/or any other comment blocks and a
description of any changes you make.
************************************************** *********************/

var fpArray = new Array();

function preMain() {

setPriceStudy(false);
setStudyTitle("SlopeTrendIndicator");
setCursorLabelName("STI",0);
setDefaultBarFgColor(Color.blue,0);
setPlotType(PLOTTYPE_LINE,0);
setDefaultBarThickness(1,0);
askForInput();

var x=0;
fpArray[x] = new FunctionParameter("Length", FunctionParameter.NUMBER);
with(fpArray[x++]){
setLowerLimit(1);
setDefault(10);
}
fpArray[x] = new FunctionParameter("Source", FunctionParameter.STRING);
with(fpArray[x++]){
addOption("open()");
addOption("high()");
addOption("low()");
addOption("close()");
addOption("hl2()");
addOption("hlc3()");
addOption("ohlc4()");
setDefault("close()");
}
fpArray[x] = new FunctionParameter("Tick", FunctionParameter.NUMBER);
with(fpArray[x++]){
setDefault(0.001);
}
fpArray[x] = new FunctionParameter("Offset", FunctionParameter.NUMBER);
with(fpArray[x++]){
setDefault(0);
}
}

var bInit = false;
var vSource = null, vLength = null, vTick = null, vOffset=null;
var xA = null, xB = null, xSTI = null;

function main(Length,Source,Tick,Offset) {
if (bInit == false) {
vLength = Length;
vSource = Source;
vTick = Tick;
vOffset = Offset;
bInit = true;
}

xA = hhv(vLength, eval(vSource)).getValue(vOffset);
xB = llv(vLength, eval(vSource)).getValue(vOffset);
xSTI = ((xA-xB)/vLength)/vTick;
return xSTI;
}