We now use some of the points on each grid and update:
k1=k[indM[indn,sind[t+1]]];
and
ks[t+1]=SmoothingFunction(k1,k[indn],ks[t]);
given k and k1 respectively starting from ks[startn]. Here, indn is an index vector
around ks[t] with nsmooth points.
We here set
0:linear interpolation
1:polynomial
2:LOESS
3:LOWESS
4:Kernel regression
5:Smoothing natural spline
6:NURBS x 10
7:Bezier Curve x 10