mouthdistbysurvey: Distance From Mouth for All Observations of Individuals

Description

Calculates distance from the mouth of a river network to all observations of each individual (given as segment and vertex). and the specified mouth of the river network. The mouth must first be specified (see setmouth). Returns a matrix of distances, with a row for each unique individual and a column for each survey.

A plotting method is provided for the output; see plotseq.

Usage

mouthdistbysurvey(
  unique,
  survey,
  seg,
  vert,
  rivers,
  logical = NULL,
  stopiferror = TRUE,
  algorithm = NULL
)

Value

A vector of river network distances (numeric), with each row corresponding to a unique fish and each column corresponding to a unique survey. Values of NA indicate the individual not being located during the survey in question.

Arguments

unique: A vector of identifiers for each fish.
survey: A vector of identifiers for each survey. It is recommended to use a numeric or date format (see as.Date) to preserve survey order.
seg: A vector of river locations (segment)
vert: A vector pf rover coordinates (vertex)
rivers: The river network object to use
logical: A boolean vector that can be used for subsetting - if used, mouthdistbysurvey() will only return distances in which a specified condition is met.
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.

Author

Matt Tyers

Examples

Run this code

data(Gulk, fakefish)

seqbysurvey <- mouthdistbysurvey(unique=fakefish$fish.id, survey=fakefish$flight.date, 
    seg=fakefish$seg, vert=fakefish$vert, rivers=Gulk)
seqbysurvey
plotseq(seqbysurvey)