library(mgcv)


x<- rnorm(200)
y<- rnorm(200)
z<-rnorm(200)

tab<-data.frame(x,y,z)
tab

#surface wireframe:

mod <- gam(z ~ te(x, y), data = tab)

wyk <- matrix(fitted(mod), ncol = 20) #8 i 10 też ok

wireframe(wyk, drape=TRUE, colorkey=TRUE)

#surface persp3d


library(rgl)
library(akima)


z_interpolation <- 200

tabint <- interp(x, y, z)

x.si <- tabint$x
y.si <- tabint$y
z.si <- tabint$z
jet.colors <- colorRampPalette( c("lightpink", "slateblue4") )
nbcol <- 200
vertcol <- cut(t, nbcol)
color = rev(rainbow(nbcol, start = 0/6, end = 4/6))
persp3d(x.si, y.si, z.si, col = color[vertcol], smooth=T)