Iterate over an array or data frame by a specified dimension.

Usage

# S3 method for array
iteror(
  obj,
  ...,
  by = c("cell", "row", "column"),
  chunkSize,
  chunks,
  recycle = FALSE,
  drop = FALSE,
  rowMajor = TRUE
)

# S3 method for matrix
iteror(
  obj,
  ...,
  by = c("cell", "row", "column"),
  chunkSize,
  chunks,
  recycle = FALSE,
  drop = FALSE,
  rowMajor = TRUE
)

# S3 method for data.frame
iteror(obj, ..., recycle = FALSE, chunkSize, chunks, by = c("column", "row"))

Arguments

obj: An object to iterate over.
...: Undocumented.
by: Which dimension to slice an array or data frame by. Can be "cell", "row", "column", or numeric dimensions.
chunkSize: The thickness of the slice to take along the specified dimension.
chunks: How many slices to take.
recycle: If TRUE, the iteror starts over on reaching the end.
drop: Whether to drop the array dimensions enumerated over.
rowMajor: If TRUE, will return slices in order with the first indices varying fastest (same as in i_enumerate).

Value

an iteror yielding from obj along the specified dimensions.

Examples

l <- iteror(letters, chunkSize=7)
as.list(l)
#> [[1]]
#> [1] "a" "b" "c" "d" "e" "f" "g"
#> 
#> [[2]]
#> [1] "h" "i" "j" "k" "l" "m" "n"
#> 
#> [[3]]
#> [1] "o" "p" "q" "r" "s" "t" "u"
#> 
#> [[4]]
#> [1] "v" "w" "x" "y" "z"
#> 

a <- array(1:8, c(2, 2, 2))

# iterate over all the slices
it <- iteror(a, by=3)
as.list(it)
#> [[1]]
#> , , 1
#> 
#>      [,1] [,2]
#> [1,]    1    3
#> [2,]    2    4
#> 
#> 
#> [[2]]
#> , , 1
#> 
#>      [,1] [,2]
#> [1,]    5    7
#> [2,]    6    8
#> 
#> 

# iterate over all the columns of each slice
it <- iteror(a, by=c(2, 3))
as.list(it)
#> [[1]]
#> , , 1
#> 
#>      [,1]
#> [1,]    1
#> [2,]    2
#> 
#> 
#> [[2]]
#> , , 1
#> 
#>      [,1]
#> [1,]    3
#> [2,]    4
#> 
#> 
#> [[3]]
#> , , 1
#> 
#>      [,1]
#> [1,]    5
#> [2,]    6
#> 
#> 
#> [[4]]
#> , , 1
#> 
#>      [,1]
#> [1,]    7
#> [2,]    8
#> 
#> 

# iterate over all the rows of each slice
it <- iteror(a, by=c(1, 3))
as.list(it)
#> [[1]]
#> , , 1
#> 
#>      [,1] [,2]
#> [1,]    1    3
#> 
#> 
#> [[2]]
#> , , 1
#> 
#>      [,1] [,2]
#> [1,]    2    4
#> 
#> 
#> [[3]]
#> , , 1
#> 
#>      [,1] [,2]
#> [1,]    5    7
#> 
#> 
#> [[4]]
#> , , 1
#> 
#>      [,1] [,2]
#> [1,]    6    8
#> 
#>