Convert a Point Shapefile to River Locations

This function reads a point shapefile and determines the closest vertex in the river network to each point of XY data, returning a data frame with river locations, defined as segment numbers and vertex numbers, along with the data table read from the input shapefile.

pointshp2segvert(path = ".", layer, rivers)

Arguments

path	File path, default is the current working directory.
layer	Name of the shapefile, without the .shp extension.
rivers	The river network object to use.

Value

A data frame of river locations, with segment numbers in $seg, vertex numbers in $vert, snapping distances in $snapdist, and the remaining columns corresponding to the data table in the input point shapefile.

Note

If the input shapefile is detected to be in a different projection than the river network, the input shapefile will be re-projected before conversion to river locations.

Examples

filepath <- system.file("extdata", package="riverdist")

fakefish_UTM5 <- pointshp2segvert(path=filepath, layer="fakefish_UTM5", rivers=Gulk)
#> OGR data source with driver: ESRI Shapefile 
#> Source: "/home/jose/R/scripts/riverdist/inst/extdata", layer: "fakefish_UTM5"
#> with 100 features
#> It has 5 fields
#> Integer64 fields read as strings:  fish_id flight 
head(fakefish_UTM5)
#>   seg vert  snapdist        x       y fish_id flight flight_dat
#> 1   1  595 329.34419 885976.9 6951164       8      1 2015/04/01
#> 2   1  399  40.27721 891727.6 6943194      10      1 2015/04/01
#> 3   1  352 402.52259 893895.8 6940549      14      1 2015/04/01
#> 4   1  116 525.06623 893894.9 6929195       7      1 2015/04/01
#> 5   1  806 355.32753 878936.0 6959825      11      1 2015/04/01
#> 6   1  505  11.34949 889340.7 6948910       9      1 2015/04/01

plot(x=Gulk)
points(fakefish_UTM5$x, fakefish_UTM5$y)
riverpoints(seg=fakefish_UTM5$seg, vert=fakefish_UTM5$vert, rivers=Gulk, pch=16, col=2)