riverdirectionmat: River Direction Matrix

In riverdist: River Network Distance Computation and Applications

River Direction Matrix

Description

Returns a matrix of calculated travel direction between every point and every other point of given river locations (segment and vertex), or of a subset. The mouth (lowest point) segment and vertex must be specified (see setmouth).

Usage

riverdirectionmat(
  seg,
  vert,
  rivers,
  logical = NULL,
  ID = NULL,
  flowconnected = FALSE,
  stopiferror = TRUE,
  algorithm = NULL
)

Arguments

seg	A vector of river locations (segment component).
vert	A vector of river locations (vertex component).
rivers	The river network object to use
logical	A boolean vector that can be used for subsetting - if used, riverdirectionmat() will only return pairwise distances in which a specified condition is met.
ID	a vector of observation IDs for aid in interpreting the output table
flowconnected	If TRUE, only returns direction if the input segments are flow-connected. Defaults to FALSE.
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

A matrix of directions (character) with rows and columns labeled by corresponding values of ID. See riverdirection for additional information.

Note

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

Author(s)

Matt Tyers

See Also

riverdirection

Examples

data(Gulk, fakefish)

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

logi1 <- (fakefish$flight.date==as.Date("2015-11-25"))

riverdirectionmat(seg=fakefish$seg, vert=fakefish$vert, rivers=Gulk, logical=logi1)

riverdist documentation built on Aug. 22, 2023, 5:06 p.m.