R: Evaluate Expression in a Spatially Sampled Function

with.ssf {spatstat.core} | R Documentation

## Evaluate Expression in a Spatially Sampled Function

### Description

Given a spatially sampled function, evaluate an expression involving the function values.

### Usage

      apply.ssf(X, ...)

      ## S3 method for class 'ssf'
    with(data, ...)

### Arguments

`X, data` | A spatially sampled function (object of class `"ssf"`).
`...` | Arguments passed to `with.default` or `apply` specifying what to compute.

### Details

An object of class `"ssf"` represents a function (real- or vector-valued) that has been sampled at a finite set of points. It contains a data frame which provides the function values at the sample points.

In `with.ssf`, the expression specified by `...` will be evaluated in this dataframe. In `apply.ssf`, the dataframe will be subjected to the `apply` operator using the additional arguments `...`.

If the result of evaluation is a data frame with one row for each data point, or a numeric vector with one entry for each data point, then the result will be an object of class `"ssf"` containing this information. Otherwise, the result will be a numeric vector.

### Value

An object of class `"ssf"` or a numeric vector.

### Author(s)

Adrian Baddeley Adrian.Baddeley@curtin.edu.au.

### See Also

`ssf`

### Examples

      a <- ssf(cells, data.frame(d=nndist(cells), i=1:npoints(cells)))
      with(a, i/d)

[Package spatstat.core version 2.3-1 Index]