Coral Trend Indicator

// Transcoded from PineScript Indicator (Coral Trend) 
// Date : 20th Dec 2015

_SECTION_BEGIN("Coral Trend Indicator");
SetChartOptions(0,chartShowArrows|chartShowDates);
_N(Title = StrFormat("{{NAME}} - {{INTERVAL}} {{DATE}} Open %g, Hi %g, Lo %g, Close %g (%.1f%%) {{VALUES}}", O, H, L, C, SelectedValue( ROC( C, 1 ) ) ));
Plot( C, "Close", ParamColor("Color", colorDefault ), styleNoTitle | ParamStyle("Style") | GetPriceStyle() ); 


sm = Param("Smoothing Period",21,2,40,1);
cd = Param("Constant D",0.4,0.1,2,0.1);

di = (sm - 1.0) / 2.0 + 1.0;
c1 = 2 / (di + 1.0);
c2 = 1 - c1;
c3 = 3.0 * (cd * cd + cd * cd * cd);
c4 = -3.0 * (2.0 * cd * cd + cd + cd * cd * cd);
c5 = 3.0 * cd + 1.0 + cd * cd * cd + 3.0 * cd * cd;

src = Close;
i1=0;
i2=0;
i3=0;
i4=0;
i5=0;
i6=0;


for(i=1;i<BarCount;i++)
{

i1[i] = c1[i]*src[i] + c2[i]*i1[i-1];
i2[i] = c1[i]*i1[i] + c2[i]*i2[i-1];
i3[i] = c1[i]*i2[i] + c2[i]*i3[i-1];
i4[i] = c1[i]*i3[i] + c2[i]*i4[i-1];
i5[i] = c1[i]*i4[i] + c2[i]*i5[i-1];
i6[i] = c1[i]*i5[i] + c2[i]*i6[i-1];

}

bfr = -cd*cd*cd*i6 + c3*(i5) + c4*(i4) + c5*(i3);

color = IIf(bfr>Ref(bfr,-1),colorGreen,colorRed);

Plot(bfr,"Coral Trend Indicator", color,styleDots|styleNoLine|styleThick);


_SECTION_END();