Sequences of NA values are replaced with values computed by linear
interpolation along rows and/or columns, provided that the neighbouring
values are sufficiently close, as defined by the fillgap parameter. If
interpolation can be done across both the row and column directions, then the
two values are averaged.
fillGapMatrix(m, fillgap = 1, debug = getOption("oceDebug"))a numeric matrix.
a vector containing 1 or 2 integers, indicating the maximum
width of gaps to be filled. If just one number is given, it is repeated
to create the pair. The first element of the pair is the maximum
fillable gap height (i.e. row separation in the matrix), and
the second is the maximum fillable gap width. The default value of
1 means that only gaps of width or height 1 can be filled. As
an exception to these rules, a negative value means to fill gaps
regardless of size. It is an error to specify a fillgap value
that is less than 1.
an integer specifying whether debugging information is
to be printed during the processing. This is a general parameter that
is used by many oce functions. Generally, setting debug=0
turns off the printing, while higher values suggest that more information
be printed. If one function calls another, it usually reduces the value of
debug first, so that a user can often obtain deeper debugging
by specifying higher debug values.
fillGapMatrix returns matrix, with NA values replaced by interpolated values as dictated by the function parameters.
library(oce)
m <- matrix(1:20, nrow = 5)
# Example 1: interpolate past across gaps of width/height equal to 1
m[2, 3] <- NA
m[3, 3] <- NA
m[4, 2] <- NA
m
#> [,1] [,2] [,3] [,4]
#> [1,] 1 6 11 16
#> [2,] 2 7 NA 17
#> [3,] 3 8 NA 18
#> [4,] 4 NA 14 19
#> [5,] 5 10 15 20
fillGapMatrix(m)
#> [,1] [,2] [,3] [,4]
#> [1,] 1 6 11 16
#> [2,] 2 7 12 17
#> [3,] 3 8 13 18
#> [4,] 4 9 14 19
#> [5,] 5 10 15 20
# Example 2: cannot interpolate across larger groups by default
m <- matrix(1:20, nrow = 5)
m[2:3, 2:3] <- NA
m
#> [,1] [,2] [,3] [,4]
#> [1,] 1 6 11 16
#> [2,] 2 NA NA 17
#> [3,] 3 NA NA 18
#> [4,] 4 9 14 19
#> [5,] 5 10 15 20
fillGapMatrix(m)
#> [,1] [,2] [,3] [,4]
#> [1,] 1 6 11 16
#> [2,] 2 NA NA 17
#> [3,] 3 NA NA 18
#> [4,] 4 9 14 19
#> [5,] 5 10 15 20
# Example 3: increasing gap lets us cover gaps of size 1 or 2
fillGapMatrix(m, fillgap = 2)
#> [,1] [,2] [,3] [,4]
#> [1,] 1 6 11 16
#> [2,] 2 7 12 17
#> [3,] 3 8 13 18
#> [4,] 4 9 14 19
#> [5,] 5 10 15 20