R: Extract Subset of Influence Object

Extract.influence.ppm {spatstat} | R Documentation

## Extract Subset of Influence Object

### Description

Extract a subset of an influence object, or extract the influence values at specified locations.

### Usage

      ## S3 method for class 'influence.ppm'
    x[i, ...]

### Arguments

`x` | A influence object (of class `"influence.ppm"`) computed by `influence.ppm`.
`i` | Subset index (passed to `[.ppp`). Either a spatial window (object of class `"owin"`) or an integer index.
`...` | Ignored.

### Details

An object of class `"influence.ppm"` contains the values of the likelihood influence for a point process model, computed by `influence.ppm`. This is effectively a marked point pattern obtained by marking each of the original data points with its likelihood influence.

This function extracts a designated subset of the influence values, either as another influence object, or as a vector of numeric values.

The function `[.influence.ppm` is a method for `[` for the class `"influence.ppm"`. The argument `i` should be an index applicable to a point pattern. It may be either a spatial window (object of class `"owin"`) or a sequence index. The result will be another influence object (of class `influence.ppm`).

To extract the influence values as a numeric vector, use `marks(as.ppp(x))`.

### Value

Another object of class `"influence.ppm"`.

### Author(s)

Adrian Baddeley Adrian.Baddeley@curtin.edu.au, Rolf Turner r.turner@auckland.ac.nz and Ege Rubak rubak@math.aau.dk

### See Also

`influence.ppm`.

### Examples

       fit <- ppm(cells, ~x)
       infl <- influence(fit)
       b <- owin(c(0.1, 0.3), c(0.2, 0.4))
       infl[b]
       infl[1:5]
       marks(as.ppp(infl))[1:3]

[Package spatstat version 1.63-3 Index]