R: Extract Subset of Pixel Image on Linear Network

Extract.linim {spatstat} | R Documentation

## Extract Subset of Pixel Image on Linear Network

### Description

Extract a subset of a pixel image on a linear network.

### Usage

      ## S3 method for class 'linim'
    x[i, ..., drop=TRUE]

### Arguments

`x` | A pixel image on a linear network (object of class `"linim"`).
`i` | Spatial window defining the subregion. Either a spatial window (an object of class `"owin"`), or a logical-valued pixel image, or any type of index that applies to a matrix, or a point pattern (an object of class `"lpp"` or `"ppp"`), or something that can be converted to a point pattern by `as.lpp` (using the network on which `x` is defined).
`...` | Additional arguments passed to `[.im`.
`drop` | Logical value indicating whether `NA` values should be omitted from the result.

### Details

This function is a method for the subset operator `"["` for pixel images on linear networks (objects of class `"linim"`).

The pixel image `x` will be restricted to the domain specified by `i`.

Pixels outside the domain of `x` are assigned the value `NA`; if `drop=TRUE` (the default) such `NA` values are deleted from the result; if `drop=FALSE`, then `NA` values are retained.

If `i` is a window (or a logical-valued pixel image) then `x[i]` is another pixel image of class `"linim"`, representing the restriction of `x` to the spatial domain specified by `i`.

If `i` is a point pattern, then `x[i]` is the vector of pixel values of `x` at the locations specified by `i`.

### Value

Another pixel image on a linear network (object of class `"linim"`) or a vector of pixel values.

### Author(s)

Adrian Baddeley Adrian.Baddeley@curtin.edu.au

### Examples

      M <- as.mask.psp(as.psp(simplenet))
      Z <- as.im(function(x,y){x}, W=M)
      Y <- linim(simplenet, Z)
      X <- runiflpp(4, simplenet)
      Y[X]
      Y[square(c(0.3, 0.6))]

[Package spatstat version 1.54-0 Index]