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replicating C example from the Extensions Manual problem

5 messages · Erin Hodgess, Berwin A Turlach, Joshua Wiley +2 more

Original
Erin Hodgess
# 
Dear R People:

Here is something that I am sure is very simple.  I'm just trying to
re-create the C convolution example in the Extensions manual.  Here is
the subroutine:

void convolve(double *a, int *na, double *b, int *nb, double *ab)
{
R_len_t i, j, nab = *na + *nb - 1;
for(i = 0; i < nab; i++)
ab[i] = 0.0;
for(i = 0; i < *na; i++)
for(j = 0; j < *nb; j++)
ab[i + j] += a[i] * b[j];
}

And here are the results from trying to compile:

erin at ubuntu:~$ R CMD SHLIB convolve.c
gcc -std=gnu99 -I/usr/share/R/include      -fpic  -O3 -pipe  -g -c
convolve.c -o convolve.o
convolve.c: In function ?convolve?:
convolve.c:3:1: error: unknown type name ?R_len_t?
make: *** [convolve.o] Error 1


What is wrong, please?

This is on Ubuntu 11.10 with R-2.14.2.  I'm sure that it's totally goofy.

Thanks,
Erin
Berwin A Turlach
# 
G'day Erin,

On Thu, 15 Mar 2012 01:03:59 -0500
Erin Hodgess <erinm.hodgess at gmail.com> wrote:

            

      
      
      
    

        
Missing

#include <R.h>
#include <Rinternals.h>

In particular the latter is defining R_len_t.  Guess that code snippet
in the manual is only showing the code of the function, but not the
complete file that needs to be compiled. :)

HTH.

Cheers,
	
	Berwin

  
  


  


      

    

    

      
      

        


  

        

      Joshua Wiley
    

    

      
      #
    

  


  

      
Hi Erin,

If you are just starting with including compiled code, I would highly
recommend the Rcpp + inline packages.  I attached a small example of
how it works, but basically you get to inline C++ code in R files.

Cheers,

Josh

P.S. I wrote this snippet awhile ago when I did not know much about
C++ so that code is sloppy, but it demonstrates the point and I am
short on time right now.

        
On Wed, Mar 14, 2012 at 11:03 PM, Erin Hodgess <erinm.hodgess at gmail.com> wrote:

            

      
      
      
    

        

      
      
    

        

  
    

      
      
    

  


  


      

    

    

      
      

        


  

        

      Jeff Newmiller
    

    

      
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Do you really expect is to know how to figure out the error if you don't give us the code that the error is pointing at (or the code preceding the error, which may be at fault)? Please think before posting.
---------------------------------------------------------------------------
Jeff Newmiller                        The     .....       .....  Go Live...
DCN:<jdnewmil at dcn.davis.ca.us>        Basics: ##.#.       ##.#.  Live Go...
                                      Live:   OO#.. Dead: OO#..  Playing
Research Engineer (Solar/Batteries            O.O#.       #.O#.  with
/Software/Embedded Controllers)               .OO#.       .OO#.  rocks...1k
--------------------------------------------------------------------------- 
Sent from my phone. Please excuse my brevity.

        
Erin Hodgess <erinm.hodgess at gmail.com> wrote:

        

            

      
      
      
    

        

      
      
    

  
  


  


      

    

    

      
      

        


  

        

      Peter Langfelder
    

    

      
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Seems you're missing the required header(s). Can't find the example in
the extensions manual but you probably need

#include <Rinternals.h>

or

#include <Rdefines.h>


HTH,

Peter

        
On Wed, Mar 14, 2012 at 11:03 PM, Erin Hodgess <erinm.hodgess at gmail.com> wrote: