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

From: Frank E Harrell Jr <>
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 mailing list PLEASE do read the posting guide! Received on Fri Oct 14 13:04:52 2005

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