# tensor() function and sets

**Martyn Plummer
**
plummer@iarc.fr

*Thu, 22 Jul 1999 09:56:44 +0200 (CEST)*

On 20-Jul-99 Jonathan Rougier wrote:
>* Hi Everyone,
*>*
*>* To complete the outer() and kronecker() functions in the base, may I
*>* suggest the following tensor() function, which allows the multiplication
*>* of arrays through sets of conformable dimensions. I am happy to write a
*>* help page if required.
*
I have some code that could certainly be tidied up with the tensor()
function [1], but I wonder if "tensor" is the right name.
1) I would expect a function called "tensor" to construct a tensor object
rather than multiply two arrays together.
2) The arguments aren't tensors. They are arrays.
How fast is it? It would be _really_ nice if this were done efficiently
in C code.
Martyn
[1] ar.yw in the "bats" package. I was just looking at this wondering how
to speed it up before rewriting the whole thing in C or Fortran.
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-devel 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-devel-request@stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._