a matrix or data frame with numerical values giving coordinates of points to be
interpolated. The first column is interpreted as independend
variable (e.g. time), the remaining columns as dependend variables.
xout
a vector (or single value for approxTime1) of
independend values specifying where interpolation has to be done.
rule
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.
...
optional parameters passed to approx.
Value
approxTime returns a matrix resp. data frame of the same structure as
x containing data which interpolate the given data with respect
to xout.
approxTime1 is a performance optimized special version with less options
than the original approx function. It returns an interpolated vector.
Details
The functions can be used for linear interpolation with a
complete matrix or data frame. This can be used for example in the
main function of an odeModel
to get input values at a specified time xout. The version
approxTime1 is less flexible (only one single value for xout and only linear
interpolation) but has increased performance.
Both functions are faster if x is a matrix instead of a data frame.