# st_line_sample: Sample points on a linear geometry In sf: Simple Features for R

## Description

Sample points on a linear geometry

## Usage

 `1` ```st_line_sample(x, n, density, type = "regular", sample = NULL) ```

## Arguments

 `x` object of class `sf`, `sfc` or `sfg` `n` integer; number of points to choose per geometry; if missing, n will be computed as `round(density * st_length(geom))`. `density` numeric; density (points per distance unit) of the sampling, possibly a vector of length equal to the number of features (otherwise recycled); `density` may be of class `units`. `type` character; indicate the sampling type, either "regular" or "random" `sample` numeric; a vector of numbers between 0 and 1 indicating the points to sample - if defined sample overrules n, density and type.

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13``` ```ls = st_sfc(st_linestring(rbind(c(0,0),c(0,1))), st_linestring(rbind(c(0,0),c(10,0)))) st_line_sample(ls, density = 1) ls = st_sfc(st_linestring(rbind(c(0,0),c(0,1))), st_linestring(rbind(c(0,0),c(.1,0))), crs = 4326) try(st_line_sample(ls, density = 1/1000)) # error st_line_sample(st_transform(ls, 3857), n = 5) # five points for each line st_line_sample(st_transform(ls, 3857), n = c(1, 3)) # one and three points st_line_sample(st_transform(ls, 3857), density = 1/1000) # one per km st_line_sample(st_transform(ls, 3857), density = c(1/1000, 1/10000)) # one per km, one per 10 km st_line_sample(st_transform(ls, 3857), density = units::set_units(1, 1/km)) # one per km # five equidistant points including start and end: st_line_sample(st_transform(ls, 3857), sample = c(0, 0.25, 0.5, 0.75, 1)) ```

sf documentation built on July 24, 2019, 5:05 p.m.