na_omit_if {naflex}

Conditionally omit missing values

Description

na_omit_if removes missing values from x if the specified checks are satisfied, and returns x unmodified otherwise. When used within summary functions, na_omit_if provides greater flexibility than the na.rm option e.g. sum(na_omit_if(x, prop = 0.05)).

Usage

na_omit_if(
  x,
  prop = NULL,
  n = NULL,
  consec = NULL,
  n_non = NULL,
  prop_strict = FALSE
)

Arguments

x

Vector to omit missing values in if checks pass.

prop

The maximum proportion (0 to 1) of missing values allowed.

n

The maximum number of missing values allowed.

consec

The maximum number of consecutive missing values allowed.

n_non

The minimum number of non-missing values required.

prop_strict

A logical (default FALSE) indicating if the proportion of missing values must be strictly less than prop (prop_strict = TRUE) or only less than prop (prop_strict = FALSE).

Details

There are four type of checks available:

• a maximum proportion of missing values allowed (prop)

• a maximum number of missing values allowed (n)

• a maximum number of consecutive missing values allowed (consec), and

• a minimum number of non-missing values required (n_non).

Any number of checks may be specified, including none. If multiple checks are specified, they must all pass in order for missing values to be omitted. If no checks are specified then missing values are omitted, since this is considered as "all" checks passing.

Value

A vector of the same type as x. Either x with missing values removed if all checks pass, or x unmodified if any checks fail.

For consistency with na.omit, if missing values are removed, the indices of the removed values form an na.action attribute of class omit in the result.

If missing values are not removed (because the checks failed or there were no missing values in x) then no na.action attribute is added.

Examples

x <- c(1, 3, NA, NA, NA, 4, 2, NA, 4, 6)

sum(na_omit_if(x, prop = 0.45, n = 10, consec = 5))
sum(na_omit_if(x, prop = 0.45))

require(magrittr)
sum(x %>% na_omit_if(prop = 0.45))

# WMO specification for calculating monthly values from daily data
daily_rain <- rnorm(30)
daily_rain[c(3, 5, 6, 7, 8, 9, 24, 28)] <- NA
sum(daily_rain %>% na_omit_if(n = 10, consec = 4))