rbindList function

rbind a list of vectors into matrix or data.frame

rbindList(
  x,
  emptyValue = "",
  nullValue = NULL,
  keepListNames = TRUE,
  newColnames = NULL,
  newRownames = NULL,
  fixBlanks = TRUE,
  returnDF = FALSE,
  verbose = FALSE,
  ...
)

Arguments

• x: list of atomic vector, matrix, or data.frame

  objects.

• emptyValue: character value to use to represent missing values, whenever a blank cell is introduced into the resulting matrix

• nullValue: optional value used to replace NULL entries in the input list, useful especially when the data was produced by strsplit() with "". Use nullValue="" to replace NULL

  with "" and preserve the original list length. Otherwise when nullValue=NULL any empty entries will be silently dropped.

• keepListNames: logical whether to use list names as rownames in the resulting matrix or data.frame.

• newColnames: NULL or character vector of colnames to use for the resulting matrix or data.frame.

• newRownames: NULL or character vector of rownames to use for the resulting matrix or data.frame. If supplied, this value overrides the keepListNames=TRUE use of list names as rownames.

• fixBlanks: logical whether to use blank values instead of repeating each vector to the length of the maximum vector length when filling each row of the matrix or data.frame.

• returnDF: logical whether to return a data.frame, by default FALSE, a matrix is returned.

• verbose: logical whether to print verbose output during processing.

• ...: Additional arguments are ignored.

Returns

matrix unless returnDF=TRUE in which the output is coerced to a data.frame. The rownames by default are derived from the list names, but the colnames are not derived from the vector names. If input x contains data.frame or matrix objects, the output will retain those values.

Details

The purpose of this function is to emulate do.call(rbind, x) on a list of vectors, while specifically handling when there are different numbers of entries per vector. The output matrix number of columns will be the longest vector (or largest number of columns) in the input list x.

Instead of recycling values in each row to fill the target number of columns, this function fills cells with blank fields, with default argument fixBlanks=TRUE.

In extensive timings tests at the time this function was created, this technique was notably faster than alternatives. It runs do.call(rbind, x) then subsequently replaces recycled values with blank entries, in a manner that is notably faster than alternative approaches such as pre-processing the input data.

Examples

L <- list(a=LETTERS[1:4], b=letters[1:3]);
rbindList(L);
rbindList(L, returnDF=TRUE);

See Also

Other jam list functions: cPaste(), heads(), jam_rapply(), list2df(), mergeAllXY(), mixedSorts(), relist_named(), rlengths(), sclass(), sdim(), uniques(), unnestList()