Estimation of the g function

Estimates the g function

Usage

ghat(X, r = NULL, ReferenceType = "", NeighborType = "", CheckArguments = TRUE)

Arguments

X

A weighted, marked, planar point pattern (wmppp.object).

r

A vector of distances. If NULL, a sensible default value is chosen (512 intervals, from 0 to half the diameter of the window) following spatstat.

ReferenceType

One of the point types. Default is all point types.

NeighborType

One of the point types. Default is all point types.

CheckArguments

Logical; if TRUE, the function arguments are verified. Should be set to FALSE to save time in simulations for example, when the arguments have been checked elsewhere.

Details

The computation of ghat relies on spatstat function sewpcf.

Value

An object of class fv, see fv.object, which can be plotted directly using plot.fv.

References

Stoyan, D. and Stoyan, H. (1994) Fractals, random shapes and point fields: methods of geometrical statistics. John Wiley and Sons.

See also

gEnvelope

Examples

data(paracou16)
autoplot(paracou16)


# Calculate g
r <- 0:30
(Paracou <- ghat(paracou16, r, "Q. Rosea", "V. Americana"))
#> Function value object (class ‘fv’)
#> for the function r -> g(r)
#> ................................................................
#>      Math.label     Description                                 
#> r    r              distance argument r                         
#> theo g[pois](r)     theoretical Poisson g(r)                    
#> iso  hat(g)[iso](r) Ripley isotropic correction estimate of g(r)
#> ................................................................
#> Default plot formula:  .~r
#> where “.” stands for ‘theo’, ‘iso’
#> Recommended range of argument r: [0, 30]
#> Available range of argument r: [0, 30]
#> Unit of length: 1 meter

# Plot
autoplot(Paracou)