window {base} | R Documentation |
window
is a generic function which
extracts the subset of the object x
observed between the times start
and end
. If a
frequency is specified, the series is then re-sampled at the new
frequency.
window(x, ...) window.default(x, start = NULL, end = NULL, frequency = NULL, deltat = NULL) window.ts(x, start = NULL, end = NULL, frequency = NULL, deltat = NULL)
x |
a time-series or other object. |
start |
the start time of the period of interest. |
end |
the end time of the period of interest. |
frequency, deltat |
the new frequency can be specified by either (or both if they are consistent). |
The start and end times can be specified as for ts
. If
there is no observation at the new start
or end
,
the immediately following (start
) or preceding (end
)
observation time is used.
Attempts to extend the series give a warning and are ignored.
The value depends on the method. window.default
will return a
vector or matrix with an appropriate tsp
attribute.
window.ts
differs from window.default
only in
ensuring the result is a ts
object.
data(presidents) window(presidents, 1960, c(1969,4)) # values in the 1960's window(presidents, deltat=1) # All Qtr1s window(presidents, start=c(1945,3), deltat=1) # All Qtr3s