nafill: Fill missing values

Description

Fast fill missing values using constant value, last observation carried forward or next observation carried backward.

Usage

nafill(x, type=c("const", "locf", "nocb"), fill=NA, nan=NA)
setnafill(x, type=c("const", "locf", "nocb"), fill=NA, nan=NA, cols=seq_along(x))

Value

A list except when the input is a vector in which case a vector is returned. For setnafill the input argument is returned, updated by reference.

Arguments

x: Vector, list, data.frame or data.table of numeric columns.
type: Character, one of "const", "locf" or "nocb". Defaults to "const".
fill: Numeric value to be used to replace missing observations. See examples.
nan: Either NaN or NA; if the former, NaN is treated as distinct from NA, otherwise, they are treated the same during replacement. See Examples.
cols: Numeric or character vector specifying columns to be updated.

Details

Only double and integer data types are currently supported.

Note that both nafill and setnafill provide some verbose output when getOption('datatable.verbose') is TRUE.

Examples

Run this code

x = 1:10
x[c(1:2, 5:6, 9:10)] = NA
nafill(x, "locf")

x = c(1, NA, NaN, 3, NaN, NA, 4)
nafill(x, "locf")
nafill(x, "locf", nan=NaN)

# fill= applies to any leftover NA
nafill(c(NA, x), "locf")
nafill(c(NA, x), "locf", fill=0)

dt = data.table(v1=x, v2=shift(x)/2, v3=shift(x, -1L)/2)
nafill(dt, "nocb")

setnafill(dt, "locf", cols=c("v2","v3"))
dt