# pointpats.J¶

class pointpats.J(pp, n=100, intervals=10, dmin=0.0, dmax=None, d=None)[source]

Estimates the J function for a point pattern [LB96]

Parameters
ppPointPattern

Point Pattern instance.

nint

Number of empty space points (random points).

intervalsint

The length of distance domain sequence.

dminfloat

The minimum of the distance domain.

dmaxfloat

The maximum of the distance domain.

dsequence

The distance domain sequence. If d is specified, intervals, dmin and dmax are ignored.

Notes

The $$J$$ function is a ratio of the hazard functions defined for $$G$$ and $$F$$:

$J(d) = \frac{1-G(d) }{1-F(d)}$

where $$G(d)$$ is the nearest neighbor distance distribution function (see G) and $$F(d)$$ is the empty space function (see F).

For a CSR process the J function equals 1. Empirical values larger than 1 are indicative of uniformity, while values below 1 suggest clustering.

Attributes
darray

The distance domain sequence.

jarray

F function over d.

Methods

 plot(self[, qq]) Plot the distance function
__init__(self, pp, n=100, intervals=10, dmin=0.0, dmax=None, d=None)[source]

Initialize self. See help(type(self)) for accurate signature.