#include<TRInterface.h>
 
using namespace ROOT::R;
void Function()
{
  TRInterface &r = TRInterface::Instance();
  r.SetVerbose(1);
  ////////////////////////////////////////
  //defining functions to be used from R//
  ////////////////////////////////////////
  TRFunctionImport c("c");
  TRFunctionImport list("list");
  TRFunctionImport asformula("as.formula");
  TRFunctionImport nls("nls");
  TRFunctionImport confint("confint");
  TRFunctionImport summary("summary");
  TRFunctionImport print("print");
  TRFunctionImport plot("plot");
  TRFunctionImport lines("lines");
  TRFunctionImport devnew("dev.new");
  TRFunctionImport devoff("dev.off");
  TRFunctionImport devcur("dev.cur");
  TRFunctionImport min("min");
  TRFunctionImport max("max");
  TRFunctionImport seq("seq");
  TRFunctionImport predict("predict");
  
  r<<"options(device='pdf')";
  
  ////////////////////////
  //doing the procedure //
  ////////////////////////
   TRObject xdata = c(-2,-1.64,-1.33,-0.7,0,0.45,1.2,1.64,2.32,2.9);
   TRObject ydata = c(0.699369,0.700462,0.695354,1.03905,1.97389,2.41143,1.91091,0.919576,-0.730975,-1.42001);
   
   TRDataFrame data;
   data["xdata"]=xdata;
   data["ydata"]=ydata;
   
   // fit = nls(ydata ~ p1*cos(p2*xdata) + p2*sin(p1*xdata), start=list(p1=1,p2=0.2))
   TRObject fit = nls(asformula("ydata ~ p1*cos(p2*xdata) + p2*sin(p1*xdata)"),Label["data"]=data, Label["start"]=list(Label["p1"]=1,Label["p2"]=0.2));
   print(summary(fit));
   
   print(confint(fit));
   
   devnew("Fitting Regression");
   plot(xdata,ydata);
   
   TRObject xgrid=seq(min(xdata),max(xdata),Label["len"]=10);
   lines(xgrid,predict(fit,xgrid),Label["col"] = "green");
   devoff(Label["which"] = devcur() );
}