Support Board

Inputs:
Price((H+L)/2),
Period(20), Delta(.1);
Vars:
gamma(0),
alpha(0), beta(0), BP(0), Trend(0);
beta = Cosine(360 / Period);
gamma = 1 / Cosine(720*delta / Period);
alpha = gamma - SquareRoot(gamma*gamma - 1);
BP = .5*(1 - alpha)*(Price - Price[2]) + beta*(1 + alpha)*BP[1] - alpha*BP[2]; Trend = Average(BP, 2*Period);
Plot1(Trend); Plot2(0);

#include "sierrachart.h"
SCDLLName ("Trend follower")

SCSFExport scsf_Trendfollower(SCStudyInterfaceRef sc)

{
SCSubgraphRef Trend = sc.Subgraph[0];
SCSubgraphRef Null = sc.Subgraph[1];

SCInputRef Price = sc.Input[0];
SCInputRef Length = sc.Input[1];
SCInputRef Delta = sc.Input[2];

SCFloatArray BP = Trend.Arrays[0];


if (sc.SetDefaults)
{
sc.GraphName = "Trend";
sc.StudyDescription = "Main indicator";

sc.GraphRegion       = 1;    
    sc.AutoLoop       = 1;
    sc.FreeDLL         = 0;

Trend.Name = "Trend follower";
Trend.DrawStyle = DRAWSTYLE_LINE;
Trend.PrimaryColor = RGB(255, 255, 255);
Trend.LineWidth = 2;

Null.Name         = "Null";
    Null.DrawStyle       = DRAWSTYLE_LINE;
    Null.PrimaryColor     = RGB(255, 0, 0);
    Null.LineWidth       = 2;
    Null.DrawZeros       = 1;

Price.Name = "Price";
Price.SetInputDataIndex(SC_HL);

Length.Name = "Length";
Length.SetInt(20);
Length.SetIntLimits(1, INT_MAX);


Delta.Name = "Delta";
Delta.SetFloat(0.10f);
Delta.SetFloatLimits(-1.00, 1.00);

return;
}

float a1, a2, a3, a4, b1, b2, b3, b4;

a1 = Delta.GetFloat();
a2 = sc.BaseData[Price.GetInputDataIndex()][sc.Index-1];
a3 = sc.BaseData[Price.GetInputDataIndex()][sc.Index-2];
a4 = sc.BaseData[Price.GetInputDataIndex()][sc.Index];
b1 = cos(360 / Length.GetInt());
b2 = 1 / cos((720*a1) / Length.GetInt());
b3 = b2 - sqrt( (b2)*(b2) - 1);

BP[sc.Index] = 0.5*(1-b3)*(a4-a3) + b1*(1+b3)*BP[sc.Index-1] - b3*BP[sc.Index-2];

Trend[sc.Index] = BP[sc.Index];
Null[sc.Index] = 0;
}