Fill missing values

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

nafill(x, type=c("const","locf","nocb"), fill=NA,
       verbose=getOption("datatable.verbose"))
setnafill(x, type=c("const","locf","nocb"), fill=NA, cols=seq_along(x),
          verbose=getOption("datatable.verbose"))

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 or integer, value to be used to fill when type=="const".
cols	numeric or character vector specifying columns to be updated.
verbose	logical, TRUE turns on timing messages to the console.

Details

Only double and integer data types are currently supported.

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.

See also

shift, data.table

Examples

x = 1:10
x[c(1:2, 5:6, 9:10)] = NA
nafill(x, "locf")
#>  [1] NA NA  3  4  4  4  7  8  8  8

dt = data.table(v1=x, v2=shift(x)/2, v3=shift(x, -1L)/2)
nafill(dt, "nocb")
#> [[1]]
#>  [1]  3  3  3  4  7  7  7  8 NA NA
#> 
#> [[2]]
#>  [1] 1.5 1.5 1.5 1.5 2.0 3.5 3.5 3.5 4.0  NA
#> 
#> [[3]]
#>  [1] 1.5 1.5 2.0 3.5 3.5 3.5 4.0  NA  NA  NA
#> 

setnafill(dt, "locf", cols=c("v2","v3"))
dt
#>     v1  v2  v3
#>  1: NA  NA  NA
#>  2: NA  NA 1.5
#>  3:  3  NA 2.0
#>  4:  4 1.5 2.0
#>  5: NA 2.0 2.0
#>  6: NA 2.0 3.5
#>  7:  7 2.0 4.0
#>  8:  8 3.5 4.0
#>  9: NA 4.0 4.0
#> 10: NA 4.0 4.0