dfOrder: Sort (order) a dataframe or matrix by multiple columns
Description
Although order will order a vector, and it is possible to order several columns of a data.frame by specifying each column individually in the call to order, dfOrder will order a dataframe by as many columns as desired.
Usage
dfOrder(object, columns)
Arguments
object
The data.frame to be sorted
columns
Column numbers to use for sorting. If positive, then they will be sorted in increasing order. If negative, then in decreasing order
Value
The original data frame is now in sorted order.
Details
This is just a simple helper function to reorder data.frames. Developed to organize IRT output from the ltm package. It is a basic add on to the order function.
See Also
This code is used in the test.irt function to combine ltm and sim.irt output.