time(x, offset=0) start(x) end(x) frequency(x) tsp(x) tsp(x) <- value
x
| a time-series. |
time
, start
, end
and frequency
are generic
functions with a default
and a ts
method (see
methods
).
tsp(x)
returns c(start(x),end(x),frequency(x))
.time
creates the vector of times at which a time series was sampled.
offset
can be used to indicate when sampling took place
in the time unit.
0
indicates the start of the unit, 0.5
the middle and
1
the end of the interval.
start
and end
extract
the times the first and last observations were taken
and frequency
returns the number of samples per unit time.
tsp(x)
returns the vector c(start(x),end(x),frequency(x))
.
It is included for compatibility with the S language.
In the assignment form, value
must be a numeric of length 3 or
NULL
which removes the "tsp"
attribute and the
"ts"
class of x
.
ts
, window
and system.time
for CPU usage.data(presidents) # a simple series plot plot(c(time(presidents)), c(presidents), type="l")