R-beta: vector + data.frame

Martyn Plummer plummer at iarc.fr
Fri Aug 21 15:45:51 CEST 1998

I was getting some strange results adding two matrices
together, when I eventually worked out that one of them
was a data frame (they both look the same when you print
them!). I was surprised to discover the following behaviour:

1) When a matrix is added to a data frame, they do not
have to conform. In fact the matrix is treated like a vector.

2) When a vector is added to a data frame, there is no check
to see if the number of rows in the data frame is a multiple
of the vector length.

Even more surprisingly, this is exactly the same as the
behaviour of S-PLUS. Bug or feature?

r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-help-request at stat.math.ethz.ch

More information about the R-help mailing list