Distance From Mouth

Calculates distance from river locations (given as vectors of segment and vertex) and the specified mouth of the river network. The mouth must first be specified (see setmouth).

mouthdist(seg, vert, rivers, stopiferror = TRUE, algorithm = NULL)

Arguments

seg	Vector of segments
vert	Vector of vertices
rivers	The river network object to use
stopiferror	Whether or not to exit with an error if a route cannot be found. If this is set to FALSE and a route cannot be found, the function will return NA in the appropriate entry. Defaults to TRUE. See detectroute.
algorithm	Which route detection algorithm to use ("Dijkstra", "sequential", or "segroutes"). If left as NULL (the default), the function will automatically make a selection. See detectroute for more details.

Value

Distance (numeric)

Note

Building routes from the river mouth to each river network segment and/or distance lookup tables will greatly reduce computation time (see buildsegroutes).

Examples

data(Gulk)

# Mouth must be specified
Gulk$mouth$mouth.seg <- 1
Gulk$mouth$mouth.vert <- 1

mouthdist(seg=4, vert=40, rivers=Gulk)
#> [1] 79793.2
mouthdist(seg=c(4,5), vert=c(40,20), rivers=Gulk)
#> [1]  79793.2 105133.2