lapplyVisits: An internal function to explore the definition of field...

In Greensway/BIRDS: Biodiversity Information Review and Decision Support

An internal function to explore the definition of field visits

Description

An internal function to explore the definition of field visits

Usage

lapplyVisits(x, dat, visitCol, spdf, minPts)

Arguments

x	an subset object to pass to apply
dat	an object of class ‘OrganizedBirds’ (organised BIRDS Spatial data frame).
visitCol	name of the column for the visits UID.
spdf	spatial object of dat.
minPts	minimum number of points, default to 3.

Value

a data.frame with summarized data per visit:

• “effortDiam”: the 2 times the maximum of the distances between the centroid of all observation points and any individual observation.

• “medianDist”: the median (Q2) of the distances between the centroid and the observations, in meters.

• “iqrDist”: the interquartile range of the distances between the centroid the observations, in meters.

• “nUniqueLoc”: the number of unique combination of coordinates (locations).

• “nClusters”: the number of clusters defined by the DBSCAN algorithm, a minimum of 3 observations per cluster within the median distance between all observations. If the number of clusters is = 0 means that there are at least 3 unique locations but observations are too spread and no cluster was found. If the number of unique locations is less than 3, observations are considered as a single cluster without outliers.

• “nOutliers”: the number of observations whose distance to any cluster is beyond the median distance between all observations.

See Also

createVisits, organiseBirds

Greensway/BIRDS documentation built on Oct. 19, 2023, 2:35 a.m.