vCats: Category column values of a GRASS vector

In adamlilith/fasterRaster: Faster Raster and Spatial Vector Processing Using 'GRASS GIS'

Category column values of a GRASS vector

Description

Returns values in the cat column of a vector in GRASS.

Usage

.vCats(x, layer = 1, db = FALSE, integer = TRUE)

Arguments

x	A GVector or the name of a vector in GRASS.
layer	Integer, numeric integer, or character: Layer from which to obtain category values.
db	Logical: If TRUE, return category numbers from the database table associated with the vector. If FALSE (default), return category numbers from the actual vector.
integer	Logical: If TRUE (default), return category values as integers. In some cases, a geometry can have multiple categories, in which case NA is returned. If FALSE, return category values as strings (and thus, if a geometry has more than one category, does not convert to NA).

Value

A vector.

Examples

if (grassStarted()) {

madRivers <- fastData("madRivers")
rivers <- fast(madRivers)

.vCats(rivers)
.vHasDatabase(rivers)
.vAsDataTable(rivers)
.vRecat(rivers) # dangerous--re-categorizes geometries!
.vValidCats(rivers)

.vDetachDatabase(rivers) # dangerous--detaches database!
.vAttachDatabase(rivers)

# Ensure we don't use this for other examples!
.rm(rivers) # delete in GRASS
rm(rivers) # delete in R

}

adamlilith/fasterRaster documentation built on Oct. 26, 2024, 4:06 p.m.