na.approx {zoo}R Documentation

Replace NA by Interpolation

Description

Generic function for replacing each NA with interpolated values.

Usage

na.approx(object, ...) 
## Default S3 method:
na.approx(object, along = index(object), na.rm = TRUE, ...)

Arguments

object object in which NAs are to be replaced
along variable to use for interpolation. Has to be numeric, is otherwise coerced to numeric.
na.rm logical. Should leading NAs be removed?
... further arguments passed to methods.

Details

By default the index associated with object is used for interpolation. Note, that if this calls index.default this gives an equidistant spacing 1:NROW(object). If object is a matrix or data.frame, the interpolation is done separately for each column.

Value

An object in which each NA in the input object is replaced by interpolating the non-NA values before and after it. Leading NAs are omitted (if na.rm = TRUE) or not replaced (if na.rm = FALSE).

See Also

zoo

Examples


z <- zoo(c(2,NA,1,4,5,2), c(1,3,4,6,7,8))

## use underlying time scale for interpolation
na.approx(z) 
## use equidistant spacing
na.approx(z, 1:6)

na.approx(zoo(c(NA,9,3,2,3,2)))
[Package zoo version 1.0-5 Index]