methods.rhohat: Methods for Intensity Functions of Spatial Covariate

In spatstat.explore: Exploratory Data Analysis for the 'spatstat' Family

Methods for Intensity Functions of Spatial Covariate

Description

These are methods for the class "rhohat".

Usage

## S3 method for class 'rhohat'
print(x, ...)

## S3 method for class 'rhohat'
plot(x, ..., do.rug=TRUE)

## S3 method for class 'rhohat'
predict(object, ..., relative=FALSE,
             what=c("rho", "lo", "hi", "se"))

## S3 method for class 'rhohat'
simulate(object, nsim=1, ..., drop=TRUE)

Arguments

x, object	An object of class "rhohat" representing a smoothed estimate of the intensity function of a point process.
...	Arguments passed to other methods.
do.rug	Logical value indicating whether to plot the observed values of the covariate as a rug plot along the horizontal axis.
relative	Logical value indicating whether to compute the estimated point process intensity (relative=FALSE) or the relative risk (relative=TRUE) in the case of a relative risk estimate.
nsim	Number of simulations to be generated.
drop	Logical value indicating what to do when nsim=1. If drop=TRUE (the default), a point pattern is returned. If drop=FALSE, a list of length 1 containing a point pattern is returned.
what	Optional character string (partially matched) specifying which value should be calculated: either the function estimate (what="rho", the default), the lower or upper end of the confidence interval (what="lo" or what="hi") or the standard error (what="se").

Details

These functions are methods for the generic commands print, plot, predict and simulate for the class "rhohat".

An object of class "rhohat" is an estimate of the intensity of a point process, as a function of a given spatial covariate. See rhohat.

The method plot.rhohat displays the estimated function \rho using plot.fv, and optionally adds a rug plot of the observed values of the covariate.

The method predict.rhohat computes a pixel image of the intensity \rho(Z(u)) at each spatial location u, where Z is the spatial covariate.

The method simulate.rhohat invokes predict.rhohat to determine the predicted intensity, and then simulates a Poisson point process with this intensity.

Value

For predict.rhohat the value is a pixel image (object of class "im" or "linim"). For simulate.rhohat the value is a point pattern (object of class "ppp" or "lpp"). For other functions, the value is NULL.

Author(s)

\adrian

See Also

rhohat

Examples

  X <-  rpoispp(function(x,y){exp(3+3*x)})
  rho <- rhohat(X, function(x,y){x})
  rho
  plot(rho)
  Y <- predict(rho)
  plot(Y)
  plot(simulate(rho), add=TRUE)
  #
  if(require("spatstat.model")) {
    fit <- ppm(X, ~x)
    rho <- rhohat(fit, "y")
    opa <- par(mfrow=c(1,2))
    plot(predict(rho))
    plot(predict(rho, relative=TRUE))
    par(opa)
    plot(predict(rho, what="se"))
  }

spatstat.explore documentation built on Oct. 22, 2024, 9:07 a.m.