[R] Dummy newbie question

ripley@stats.ox.ac.uk ripley at stats.ox.ac.uk
Wed Apr 24 10:07:30 CEST 2002

On Wed, 24 Apr 2002, Julien Barnier wrote:

> Excuse me for a so dummy question, but I really can't manage to do this
> very simple thing : I have a data frame, and I would like to calculate
> two vectors which contain the sums respectively of the rows and of the
> columns of the matrix.

A data frame or a matrix?  You can only do this for data frames all of
whose columns are numeric, or for numeric matrices.  Suppose A is either
sort of object:

apply(A, 1, sum)  # row sums
apply(A, 2, sum)  # columns sums

As from next week's R 1.5.0 you will be able to use rowSums(A) and

> There is surely a very simple way to do that, but I didn't find it...

Not `very simple' until next week.

Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272860 (secr)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595

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