Hi,

So I am having problems with TSpline fitting for some data sets. I wanted to try TSpline over normal fitting on some suggestions. The TSpline fits perfectly for small data sets close together but for this data set, it doesn’t. I have attached the picture below. The green line is TSpline.

. I have tried using data points as Knots. Here is the following code :```
Double_t xx[12]={0};
Double_t yy[12]={0};
for(int i=0;i<12;++i){
xx[i]=numbers3[i]; // x data points
yy[i]=numbers5[i]; // y data points
}
TSpline3 *spline3 = new TSpline3("Test",xx,yy,12,0,3000);
spline3->Draw("same");
spline3->SetLineColor(kGreen);
spline3->SetLineWidth(3);
```

Thank you for your answers/suggestions in advance.