R help - Jun 2009 - C++ to R : 64bit to 32bit problem.

Hi,

I'm new to calling C++/C programs from R and am having some trouble getting
started.  Following Sigal Blay (Simon Fraser University)'s instructions, I
have a .c file called "useC1.c":

/* useC1.c                */

void useC(int *i) {
    i[0] = 11;
}


This produces a .o file : "useC1.o" in a specified directory.  I then
open
R, set the proper directory and:


 dyn.load("useC1.o")

Unfortunately I am met with the following:

Error in inDL(x, as.logical(local), as.logical(now), ...) :
  unable to load shared library 'C:/Users/Harlan/Desktop/useC1.o':
  LoadLibrary failure:  %1 is not a valid Win32 application.


My guess is that this is due to the fact that I am running Windows Vista
with 64bit and R is built on 32bit.  Any suggestions to fix this problem ?
 Or any easier ways for someone in my situation to call  C++ from R?

Thanks,

Harlan Campbell
McGill University

	[[alternative HTML version deleted]]

On Tue, 2 Jun 2009, H c wrote:
> Hi,
>
> I'm new to calling C++/C programs from R and am having some trouble
getting
> started.  Following Sigal Blay (Simon Fraser University)'s
instructions, I
> have a .c file called "useC1.c":
>
> /* useC1.c                */
>
> void useC(int *i) {
>    i[0] = 11;
> }
>
>
> This produces a .o file : "useC1.o" in a specified directory.  I
then open
> R, set the proper directory and:
>
>
> dyn.load("useC1.o")
That's not what Sigal Blay's instructions say (if you mean 
http://www.sfu.ca/~sblay/R-C-interface.txt) They say
   dyn.load("useC1.so")

Now, that won't work either, because the correct extension under Windows 
is .dll rather than .so (look at .Platform to see the correct extension 
for your platform).

If you do
   dyn.load("useC1.dll")
the rest of the instructions should work.  They do for me on Vista.

 	-thomas

Thomas Lumley			Assoc. Professor, Biostatistics
tlumley at u.washington.edu	University of Washington, Seattle