Re: [R] aggregate slow with many rows - alternative?

From: Frank E Harrell Jr <f.harrell_at_vanderbilt.edu>
Date: Fri 14 Oct 2005 - 12:59:52 EST

Gabor Grothendieck wrote:
> Convert dat to a matrix and see if working with the
> matrix instead of a data frame speeds things up
> enough.

In the Hmisc package the asNumericMatrix and matrix2dataFrame functions facilite this.

Also look at the summarize and mApply functions in Hmisc, which can be quite fast.

Frank Harrell



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