CrunchGeography-class: Geography properties for crunch variables
Description
Crunch stores geographic data as variable metadata. There are a number of
functions that help access and change this metadata.
Usage
CrunchGeography(..., data = NULL)
geo(x)
geo(x) <- value
# S4 method for CrunchVariable
geo(x)
# S4 method for CrunchVariable,CrunchGeography
geo(x) <- value
# S4 method for CrunchVariable,`NULL`
geo(x) <- value
availableGeodata(x = getAPIRoot())
Value
geographic information of class CrunchGeography (NULL if there is none)
Arguments
...
for CrunchGeography, named arguments from which to construct a
CrunchGeography: geodatum, feature_key, and match_field
data
for CrunchGeography, list of named arguments from which to construct a
CrunchGeography: geodatum, feature_key, and match_field
x
a crunch variable
value
value of the geography property to set
Details
geo retrieves the geographic information associate with a variable.
If there is geographic information it returns an object of class
CrunchGeography otherwise it returns NULL.
CrunchGeography objects store geography metadata from a variable. There are three slots:
geodatum an object of class CrunchGeodata which stores references
to the Crunch-hosted (geo|topo)json to use
feature_key a character string representing the feature inside of the
(geo|topo)json which is used to match match_field (e.g. properties.name)
match_field a character string representing the variable metadata information which is used
to match feature_key to (e.g. name)