nWadeableStations: Estimates the intended number of wadeable thalweg stations to...
In jasonelaw/nrsa: Calculate metrics for NRSA protocol data.

Description Usage Arguments Details Examples

View source: R/nWadeableStationsPerTransect.r

Estimates the intended number of wadeable thalweg stations at each transect which are considered sampled (even if there is no data) for the purposes of calculating residual pools and channel lengths. The number of stations at a transect is calculated as the greater of either the number of stations occuring in the dataframe for that transect, or the most common count of stations (i.e. station mode) occuring at that site.

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nWadeableStations(uid, transect, station, by = c("transect", "site"))

nWadeableStationsPerTransect(uid, transect, station)

`uid`	a vector of site identifiers
`transect`	a vector of transect identifiers
`station`	a vector of station identifiers
`by`

It takes advantage of the fact that stations are numeric, and thus that the last station to be expected for a transect is the number of transects to be expected at that transect, adding 1 to the station to account for station numbering starting at 0. Transect K always has 1 station.

The by option allows you to calculate the number of stations by site or transect. Doing it by site makes the calculations of reach length (in calculateWadeableReachLength) easier.

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d <- expand.grid(uid = 1:10, transects = LETTERS[1:11], station = 0:9)
nWadeableStations(d$uid, d$transects, d$station, by = 'site')
nWadeableStationsPerTransect(d$uid, d$transects, d$station)