[R] allocating memory in C, not in R

Sigal Blay sblay at sfu.ca
Thu Sep 2 01:41:36 CEST 2004

Thank you for the fast reply.

Below is a simplified version of my c function that I am 
currenctly using with a .C() call.
The values that has to be returned to R are the three outVectors.
If I need to convert .C to .Call,
How do I do it based on myFunction below?

Thank you for your help.

void myFunction(char **argv, int *inputVector, 
  int *RoutVector1, double *RoutVector2, char **RoutVector3) {
    int    *outVector1;
    double *outVector2;
    char   **outVector3;
    int roof = 0;
    roof = calculate_values ( argv[0], 
                              &outVector3   )

    for(i=0;i<roof;i++) {
        RoutVector1[i] = outVector1[i];    
        RoutVector2[i] = outVector2[i]; 

On Wed, Sep 01, 2004 at 10:16:59PM +0100, Prof Brian Ripley wrote:
> On Wed, 1 Sep 2004, S. Blay wrote:
> > I need to retrieve several vectors of various types from a call 
> > to .C(), but I don't know their length in advance. 
> > Is there a way to do this without allocating an excessive amount 
> > of memory? 
> > If so, an example would be very helpful.
> It would be very much easier to use .Call rather than .C.
> Alternatively, generate and allocate in C on one C call and retrieve on a
> second, as rpart does.
> -- 
> 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

More information about the R-help mailing list