[R] New problem
Prof Brian Ripley
ripley at stats.ox.ac.uk
Thu Apr 10 17:28:49 CEST 2003
On Thu, 10 Apr 2003, Ramzi Feghali wrote:
> in fact i know that R deals with logical numbers 0 and 1 the same way
> like TRUE and FALSE but my problem is in fact with C language.
Could you please use a meaningful subject line.
> I have done an interface with C and my first problem was with float
> variables, but this warning doesn't appear everytime and really i don't
> know the problem with R:
> "Warning message:
> DLL attempted to change FPU control word from 8001f to 9001f"
That's not a problem with R, that is R complaining (correctly) about your
compiled code. See e.g. the CHANGES file. I am surmising that you are
using Windows (without saying so) and not using the recommended compiler
(without saying so). If you follow the recommendations you will not see
> The second problem is how to define my matrix in the function call of R
> so that C take it as an input, knowing that for C this matrix is dfine
> as: "int M[dimrow][dimcol]" and for R is define as.matrix(m),
An R array is not a C matrix: it is a vector with attributes. There are
examples in the `Writing R Extensions' manual, `S Programming' and in many
of the 207 packages on CRAN.
> it really hurts interfacing with R
There is an easy way, via reading the manuals, and a hard way, via
trial-and-error. Your choice, but you will not get sympathy for the
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 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595
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