over-methods {spacetime} | R Documentation |
consistent spatio-temporal overlay for objects inheriting from ST
Description
consistent spatio-temporal overlay for STF, STS and STI objects, as well as their *DF counterpart: retrieves the indexes or attributes from one geometry at the spatio-temporal points of another
Usage
## S4 method for signature 'STF,STF'
over(x, y, returnList = FALSE, fn = NULL, ...)
## S4 method for signature 'xts,xts'
over(x, y, returnList = FALSE, fn = NULL, ...)
## S4 method for signature 'ST'
aggregate(x, by, FUN, ..., simplify = TRUE)
Arguments
x |
geometry (S/T locations) of the queries |
y |
layer from which the geometries or attributes are queried |
returnList |
logical; determines whether a list is returned, or an index vector |
fn |
(optional) a function; see value |
by |
geometry over which attributes in |
FUN |
aggregation function |
simplify |
boolean; if TRUE, and space or time dimensions can be
dropped, the simpler ( |
... |
arguments passed on to function fn or FUN |
Value
an object of length length(x)
, or a data.frame with number
of rows equal to length(x)
. If returnList
is FALSE,
a vector with indices of y
for each geometry (point, grid
cell centre, polygon or lines x time point) in x
. if returnList
is
TRUE, a list of length length(x)
, with list element i
the vector of indices of the geometries in y
that correspond
to the $i$-th geometry in x
.
The aggregate
method for ST
objects aggregates the attribute values of x
over the geometry (space, time, or space-time) of by
, using
aggregation function FUN
.
For the matching of time intervals, see timeMatch.
For setting, or retrieving whether time represents intervals, see timeIsInterval.
Methods
- x = "STF", y = "STF"
- x = "xts", y = "xts"
finds the row index of the instance or interval of time instances of
x
matching toy
. Only iftimeIsInterval(x) == TRUE
, intervals are sought. In that case, time intervals start at the time instance of a record, and end at the next. The last time interval length is set to the interval length of the one-but-last (non-zero) interval. In case of a single time instance fory
, its interval is right-open.
Note
See also over; methods intersecting SpatialLines with anything else, or SpatialPolygons with SpatialPolygons, need rgeos to be loaded first.
Author(s)
Edzer Pebesma, edzer.pebesma@uni-muenster.de
References
https://www.jstatsoft.org/article/view/v051i07
See Also
over; vignette('sto')
, vignette('over')
,
timeMatch, timeIsInterval