| funxy {spatstat} | R Documentation |
A simple class of functions of spatial location
funxy(f, W)
f |
A |
W |
Window (object of class |
This creates an object of class "funxy".
This is a simple mechanism for handling a function
of spatial location f(x,y) to make it easier to display
and manipulate.
f should be a function in the R language.
The first two arguments of f must be named x and y
respectively.
W should be a window (object of class "owin") inside which the
function f is well-defined.
The function f should be vectorised: that is,
if x and y are numeric vectors of the same length
n, then v <- f(x,y) should be a vector of length
n.
The resulting function g <- funxy(f, W) has the same formal
arguments as f. It accepts numeric vectors x,y as
described above, but if y is missing, then x may be
a point pattern (object of class "ppp" or "lpp") from
which the coordinates should be extracted.
A function with the same arguments as f,
which also belongs to the class "funxy".
This class has methods for
print, plot, contour and persp.
Adrian Baddeley Adrian.Baddeley@curtin.edu.au, Rolf Turner r.turner@auckland.ac.nz and Ege Rubak rubak@math.aau.dk.
f <- function(x,y) { x^2 + y^2 - 1}
g <- funxy(f, square(2))
g(0.2, 0.3)
g
g(cells[1:4])