ttestmap: Test of Effect in Locally Fitted Point Process Model

In spatstat.local: Extension to 'spatstat' for Local Composite Likelihood

Test of Effect in Locally Fitted Point Process Model

Description

Perform a local t-test for the presence of a covariate effect in a locally fitted Poisson or Gibbs point process model.

Usage

ttestmap(object, term, ...,
         method = c("exact", "hessian", "taylor"),
         grid = FALSE, 
         ngrid = NULL, grideps = NULL,
         verbose = TRUE)

Arguments

object	Locally fitted Poisson or Gibbs point process model (object of class "locppm").
term	Term to be dropped from the model. A character string matching a term in the model formula
...	Ignored.
method	Choice of method to be used to evaluate the t statistic. See Details.
grid	Logical. If FALSE, compute the test statistic at all quadrature points of the model. If TRUE, compute at a coarse grid of locations.
ngrid	Number of grid points (in each axis direction) for the coarse grid. Incompatible with grideps.
grideps	Spacing (horizontal and vertical) between grid points for the coarse grid. Incompatible with ngrid.
verbose	Logical value indicating whether to print progress reports.

Details

The argument object should be a locally-fitted Poisson or Gibbs point process model (object of class "locppm" created by locppm).

This function computes the local t test statistic for the test that a particular covariate effect in the model is zero. This is described in Baddeley (2016, sections 3 and 5).

Value

Object of class "ssf".

Author(s)

\adrian

.

References

\localpaper \baddrubaturnbook

See Also

locppm

Examples

 fit <- with(copper,
        locppm(Points, ~D, covariates=list(D=distfun(Lines)), nd=c(7,15)))
 plot(ttestmap(fit, "D"))

spatstat.local documentation built on Nov. 13, 2022, 9:06 a.m.