getLapplyIndex: getLapplyIndex: Access Index of List Element Within lapply()

In mwrowe/microRutils: Mike Rowe's Miscellaneous R Utility Functions

Description

Get name/index of current list element from within FUN argument of lapply()

• This is meant to be called from within the FUN argument passed to lapply(); it cannot be used as the FUN argument itself.

• It will also return the index along the current dimension DIM if called from a function within the apply() function, though without a name.

• This function enables the user to change the processing that occurs within FUN according to which element is being operated on.

Usage

getLapplyIndex()

Value

Returns an integer value indicating the current index of the list passed as the X argument to lapply(). If X is named, the name of the current element will be the name of the index.

Author(s)

M.W.Rowe, [e-mail]

Examples

  x <- list(a=1:10, b=1:10, c=1:10)
  FUNS <- list(a=mean, b=prod, c=max)
  FUN <- function(x){
     ndx <- getLapplyIndex()
     y <- FUNS[[names(ndx)]](x)
     y
  }
  lapply(x, FUN)

mwrowe/microRutils documentation built on June 12, 2021, 2:41 p.m.