Calls approxfun or splinefun
to interpolate missing values in a tis object.
interpNA(x, method = "constant", useTimes = F, offset = 1, rule = 2, f = 0, ...)a tis time series
One of c("constant", "linear", "fmm", "natural",
"periodic"). Methods "constant" and "linear" call approxfun;
the others call splinefun.
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.
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.
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
NAs are returned for such points and if it is 2, the
value at the closest data extreme is used.
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".
A tis object like x with NA values filled
in by interpolated values.
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.