as.surface {funfits} | R Documentation |
as.surface(grid.list, z, order.variables="xy")
grid.list |
A description of the grid used to evaluate the function. This can
either be in the form of a grid.list the grid of points produced
by make.surface.grid
|
z |
The value of the function evaluated at the gridded points.
|
order.variables |
Either "xy" or "yx" specifies how the x and y variables used to
evaluate the function are matched with the x and y grids in the surface
object.
|
A list of class surface. This object is a modest generalization of the list input format for the S functions contour, image or persp. Besides the x, y and z components there are also components xlab, ylab, and main that are used by the surface function to add axis labels and a title.
grid.list, make.surface.grid, surface, contour
# Make a perspective of the surface Z= X**2 -Y**2 # Do this by evaluating quadratic function on a 25 X 25 grid grid.l<- list( X= seq( -2,2,,25), Y= seq( -2,2,,25)) make.surface.grid( grid.l)-> xg # xg is a 625X2 matrix that has all pairs of X and Y grid values xg[,1]**2 - xg[,2]**2 -> z # now fold z in the matrix format needed for persp as.surface( grid.l, z)-> out.p persp( out.p) # also try plot( out.p) to see the default plot for a surface object