zoo: na.aggregate – R documentation

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na.aggregate

Replace NA by Aggregation

Description

Generic function for replacing each NA with aggregated values. This allows imputing by the overall mean, by monthly means, etc.

Usage

na.aggregate(object, ...)
## Default S3 method:
na.aggregate(object, by = 1, ..., FUN = mean,
             na.rm = FALSE, maxgap = Inf)

Arguments

`object`	an object.
`by`	a grouping variable corresponding to `object`, or a function to be applied to `time(object)` to generate the groups.
`...`	further arguments passed to `by` if `by` is a function.
`FUN`	function to apply to the non-missing values in each group defined by `by`.
`na.rm`	logical. Should any remaining `NA`s be removed?
`maxgap`	maximum number of consecutive `NA`s to fill. Any longer gaps will be left unchanged.

Value

An object in which each NA in the input object is replaced by the mean (or other function) of its group, defined by by. This is done for each series in a multi-column object. Common choices for the aggregation group are a year, a month, all calendar months, etc.

If a group has no non-missing values, the default aggregation function mean will return NaN. Specify na.rm = TRUE to omit such remaining missing values.

Examples

z <- zoo(c(1, NA, 3:9),
         c(as.Date("2010-01-01") + 0:2,
           as.Date("2010-02-01") + 0:2,
           as.Date("2011-01-01") + 0:2))
## overall mean
na.aggregate(z)
## group by months
na.aggregate(z, as.yearmon)
## group by calendar months
na.aggregate(z, months)
## group by years
na.aggregate(z, format, "%Y")

zoo

S3 Infrastructure for Regular and Irregular Time Series (Z's Ordered Observations)

v1.8-10

GPL-2 | GPL-3

Authors

Achim Zeileis [aut, cre] (<https://orcid.org/0000-0003-0918-3766>), Gabor Grothendieck [aut], Jeffrey A. Ryan [aut], Joshua M. Ulrich [ctb], Felix Andrews [ctb]

Initial release

2022-04-15