R: Predefined point of interest filters

filters {lidR} | R Documentation

## Predefined point of interest filters

### Description

Select only some returns

### Usage

    filter_first(las)

    filter_firstlast(las)

    filter_firstofmany(las)

    filter_ground(las)

    filter_last(las)

    filter_nth(las, n)

    filter_single(las)

### Arguments

`las` | An object of class `LAS`
`n` | the position in the return sequence

### Details

- `filter_first` Select only the first returns.

- `filter_firstlast` Select only the first and last returns.

- `filter_ground` Select only the returns classified as ground according to LAS specification.

- `filter_last` Select only the last returns i.e. the last returns and the single returns.

- `filter_nth` Select the returns from their position in the return sequence.

- `filter_firstofmany` Select only the first returns from pulses which returned multiple points.

- `filter_single` Select only the returns that return only one point.

### Value

An object of class `LAS`

### See Also

Other filters: `filter_duplicates()`, `filter_poi()`, `filter_surfacepoints()`

Other filters: `filter_duplicates()`, `filter_poi()`, `filter_surfacepoints()`

Other filters: `filter_duplicates()`, `filter_poi()`, `filter_surfacepoints()`

Other filters: `filter_duplicates()`, `filter_poi()`, `filter_surfacepoints()`

Other filters: `filter_duplicates()`, `filter_poi()`, `filter_surfacepoints()`

Other filters: `filter_duplicates()`, `filter_poi()`, `filter_surfacepoints()`

Other filters: `filter_duplicates()`, `filter_poi()`, `filter_surfacepoints()`

Other filters: `filter_duplicates()`, `filter_poi()`, `filter_surfacepoints()`

### Examples

    LASfile <- system.file("extdata", "Megaplot.laz", package="lidR")
    lidar = readLAS(LASfile)

    firstReturns  = filter_first(lidar)
    groundReturns = filter_ground(lidar)

[Package lidR version 3.2.2 Index]