connectsegs {riverdist}

Connect Segments

Description

Provides a method to manually connect unconnected segments within a river network. The nearest endpoint (or vertex) of the second segment is added as a new vertex to the first, and the network topology is then updated.

Usage

connectsegs(
  connect,
  connectto,
  nearestvert = TRUE,
  rivers,
  calcconnections = TRUE
)

Arguments

connect

The segment(s) to connect to the network. Typically, this is the segment that is disconnected from the rest of the river network. A vector of segments may be used.

connectto

The segment(s) to connect it (them) to. Typically, this is a segment that is connected to the rest of the river network. A vector of segments may be used, corresponding to that used in connect=.

nearestvert

Whether to connect at the nearest vertex and split the segment (FALSE), or connect at the nearest endpoint (TRUE). Defaults to TRUE. A vector may be used, corresponding to those used in connect= and connectto=.

rivers

The river network object to use.

calcconnections

Whether to recalculate all connections. Defaults to TRUE. Setting to FALSE is not recommended unless many connections are to be made, in which case connections can be calculated afterward.

Value

A new river network object with the specified segments connected (see rivernetwork)

Note

This function is called within cleanup, which is recommended in most cases.

Author(s)

Matt Tyers

See Also

line2network

Examples

data(Koyukuk0)
plot(Koyukuk0, ylim=c(1930500,1931500), xlim=c(194900,195100))
topologydots(Koyukuk0, add=TRUE)

Koyukuk0.1 <- connectsegs(connect=21, connectto=20, rivers=Koyukuk0)
plot(Koyukuk0.1,ylim=c(1930500,1931500), xlim=c(194900,195100))
topologydots(Koyukuk0.1, add=TRUE)

# or the vector version
zoomtoseg(seg=21:23, rivers=Koyukuk0)
Koyukuk0.2 <- connectsegs(connect=c(20,21,22), connectto=c(21,22,23), 
    nearestvert=c(FALSE,FALSE,TRUE), rivers=Koyukuk0)
zoomtoseg(seg=21:23, rivers=Koyukuk0.2)
topologydots(Koyukuk0.2, add=TRUE)