Define leakage-safe SOM preprocessing

Usage

som_preprocess(
  transform = "identity",
  center = TRUE,
  scale = TRUE,
  zero_replacement = NULL
)

Arguments

transform: One of "identity", "log", "log1p", "sqrt", "hellinger" or "clr". "log" denotes the natural logarithm. A vector can assign "identity", "log1p", "log" or "sqrt" by column; name that vector to protect against column-order changes. Hellinger and CLR are whole-matrix transformations and must be specified alone.
center: Whether to subtract training-set column means.
scale: Whether to divide by training-set column standard deviations.
zero_replacement: Positive replacement required when transform = "clr" and zeros are present.

Value

A preprocessing specification of class som_preprocess.

Examples

som_preprocess(transform = c("log", "identity"))
#> $transform
#> [1] "log"      "identity"
#> 
#> $center
#> [1] TRUE
#> 
#> $scale
#> [1] TRUE
#> 
#> $zero_replacement
#> NULL
#> 
#> attr(,"class")
#> [1] "som_preprocess"
#> attr(,"som_contract_version")
#> [1] "1.2.0"