interpNA {tis} | R Documentation |
Interpolate missing values in a Time Indexed Series
Description
Calls approxfun
or splinefun
to interpolate missing values in a tis
object.
Usage
interpNA(x, method = "constant", useTimes = F, offset = 1, rule = 2, f = 0, ...)
Arguments
x |
a tis time series
|
method |
One of c("constant", "linear", "fmm", "natural",
"periodic"). Methods "constant" and "linear" call approxfun ;
the others call splinefun .
|
useTimes |
if TRUE , use time(x, offset) (the
decimal times of x ) as the 'x' part of the (x, y) pairs used for
interpolation. If FALSE (the default), use ti(x) (the
integer time indices of x ) as the 'x' part of the (x, y) pairs.
|
offset |
if useTimes is TRUE , a number in the range
[0,1] telling where in the periods represented by ti(x) to
get the points for the 'x' parts of the (x, y) pairs. See the help
for jul for a more detailed explanation of this parameter.
|
rule |
For methods "constant" and "linear": an integer describing
how interpolation is to take place outside the interval
[min(x) , max(x) ]. If rule is 1 then
NA s are returned for such points and if it is 2 , the
value at the closest data extreme is used.
|
f |
For method="constant" a number between 0 and 1
inclusive, indicating a compromise between left- and
right-continuous step functions. If y0 and y1 are the
values to the left and right of the point then the value is
y0*(1-f)+y1*f so that f=0 is right-continuous and
f=1 is left-continuous.
|
... |
Other arguments passed along to approxfun for
methods "constant" and "linear".
|
Details
Depending on the method specified, a call to either
approxfun
or splinefun
is constructed with appropriate
arguments and executed for each column of x
. In the call to
approxfun
or splinefun
, the time indices ti(x)
(or the decimal times returned by time(x, offset)
, if
useTimes
is TRUE
) serve as the 'x' argument and the
column values as the 'y' argument.
Value
A tis
object like x
with NA
values filled
in by interpolated values.
See Also
approxfun
, splinefun
,
ti
[Package
tis version 1.18
Index]