splitBy {doBy} | R Documentation |
Split a dataframe according to the levels of variables in the dataframe. The variables to split by can be given as a formula or as a character vector.
splitBy(formula, data = parent.frame(), drop=TRUE, return.matrix=FALSE) ## S3 method for class 'splitByData' print(x, ...)
formula |
The right hand side of a formula (or a character vector) |
data |
A data frame |
drop |
Logical indicating if levels that do not occur should be dropped |
return.matrix |
Should the returned list consist of dataframs or matrices, see 'details' below |
x |
A splitByData object (basically a list). |
... |
Additional arguments, currently not used. |
The funcion transform the dataframe 'data' into a numerical matrix (using the 'asNumericMatrix' function from the Hmisc package) and makes the splitting operation on this. If return.matrix is TRUE, then these matrices are returned, otherwise the matrices are turned into dataframes and then these are returned.
A list of dataframes of matrices
Søren Højsgaard, sorenh at mail dot dk
orderBy
,
summaryBy
,
transformBy
,
lapplyBy
,
data(dietox) splitBy(formula = ~Evit+Cu, data = dietox)