smoothing by spline functions
[pt]=smooth(ptd [,step])
:ptd (2xn) real vector : :step real (discretization step of abscissae) : :pt (2xn) real vector :
this function computes interpolation by spline functions for a given set of points in the plane. The coordinates are (ptd(1,i),ptd(2,i)). The components ptd(1,:) must be in ascending order. The default value for the step is abs(max(ptd(1,:))-min(ptd(1,:)))/100
x=[1 10 20 30 40];
y=[1 30 -10 20 40];
`plot2d`_(x',y',[3],"011"," ",[-10,-40,50,50]);
yi=smooth([x;y],0.1);
`plot2d`_(yi(1,:)',yi(2,:)',[1],"000");