R: Spatial Interpolation Algorithm

tin {lidR} | R Documentation

## Spatial Interpolation Algorithm

### Description

This function is made to be used in grid_terrain or normalize_height. It implements an algorithm for spatial interpolation. Spatial interpolation is based on a Delaunay triangulation, which performs a linear interpolation within each triangle. There are usually a few points outside the convex hull, determined by the ground points at the very edge of the dataset, that cannot be interpolated with a triangulation. Extrapolation is done using the nearest neighbour approach.

### Usage

    tin(..., extrapolate = knnidw(3, 1, 50))

### Arguments

`...` | unused
`extrapolate` | There are usually a few points outside the convex hull, determined by the ground points at the very edge of the dataset, that cannot be interpolated with a triangulation. Extrapolation is done using the nearest neighbour approach by default using knnidw.

### See Also

Other spatial interpolation algorithms: `knnidw()`, `kriging()`

### Examples

    LASfile <- system.file("extdata", "Topography.laz", package="lidR")
    las = readLAS(LASfile, filter = "-inside 273450 5274350 273550 5274450")

    #plot(las)

    dtm = grid_terrain(las, algorithm = tin())

    plot(dtm, col = terrain.colors(50))
    #plot_dtm3d(dtm)

[Package lidR version 3.2.2 Index]