Re: [R] allocating memory in C, not in R
Sigal Blay wrote:
Thanks Sundar - but how do I return several vector objects of
different modes wrapped in a list object using .Call?
Sigal
Have you looked at the documentation as I suggested? It's there in
Section 4.8 of Writing R Extensions. Take a look at the examples for
lapply or look at Rdefines.h and Rinternals.h in the src/include
directory.
You're lucky I have an already worked example I have used for myself in
the past which I include below.
/* junk.c */
#include R.h
#include Rdefines.h
SEXP junk(SEXP n) {
SEXP *p_b, *p_nm;
SEXP val, a, b, c, val_nm;
double *p_a;
int *p_c;
int i, len, val_len;
char *nm[3] = {numeric, character, integer};
char *LETTERS[26] = {A, B, C, D, E, F,
G, H, I, J, K, L,
M, N, O, P, Q, R,
S, T, U, V, W, X,
Y, Z};
val_len = 3;
len = INTEGER_VALUE(n);
PROTECT(val = allocVector(VECSXP, val_len));
PROTECT(a = NEW_NUMERIC(len));
PROTECT(b = NEW_CHARACTER(len));
PROTECT(c = NEW_INTEGER(len));
PROTECT(val_nm = NEW_CHARACTER(val_len));
p_a = NUMERIC_POINTER(a);
p_b = CHARACTER_POINTER(b);
p_c = INTEGER_POINTER(c);
p_nm = CHARACTER_POINTER(val_nm);
for(i = 0; i len; i++) {
p_a[i] = 1/(double)(i + 1);
p_b[i] = mkChar(LETTERS[i % 26]);
p_c[i] = i + 1;
}
for(i = 0; i val_len; i++)
p_nm[i] = mkChar(nm[i]);
SET_VECTOR_ELT(val, 0, a);
SET_VECTOR_ELT(val, 1, b);
SET_VECTOR_ELT(val, 2, c);
setAttrib(val, R_NamesSymbol, val_nm);
UNPROTECT(5);
return val;
}
/* ## in R */
/* dyn.load(junk) */
/* junk - function(n = 1) .Call(junk, n) */
/* junk(4) */
--sundar
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Re: [R] allocating memory in C, not in R
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],
inputVector,
outVector1,
outVector2,
outVector3 )
for(i=0;iroof;i++) {
RoutVector1[i] = outVector1[i];
RoutVector2[i] = outVector2[i];
}
return;
}
Well, you could read Writing R Extensions (Section 4.8). Your
function will have to change significantly, though. I would
create a list within the C-function (called val below) and
populate the RoutVectors with it.
(I can't remember whether you'll need more than #include R.h.
Again, I direct you to the documentation.)
SEXP myFunction(SEXP argv, SEXP inputVector) {
SEXP val;
PROTECT(val = allocVector(VECSXP, 3));
/* some code you'll have to write */
UNPROTECT(1);
return val;
}
# in R
RoutVectors - .Call(myFunction, argv, inputVector)
--sundar
Thanks Sundar - but how do I return several vector objects of
different modes wrapped in a list object using .Call?
Sigal
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[R] allocating memory in C, not in R
Dear R helpers, 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. S. Blay Department of Statistics and Actuarial Science Simon Fraser University, Vancouver, British Columbia __ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
Re: [R] allocating memory in C, not in R
S. Blay wrote: Dear R helpers, 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. You should probably use the .Call interface instead of .C in this case. --sundar __ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
Re: [R] allocating memory in C, not in R
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, [EMAIL PROTECTED] 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, UKFax: +44 1865 272595 __ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
Re: [R] allocating memory in C, not in R
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],
inputVector,
outVector1,
outVector2,
outVector3 )
for(i=0;iroof;i++) {
RoutVector1[i] = outVector1[i];
RoutVector2[i] = outVector2[i];
}
return;
}
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, [EMAIL PROTECTED]
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, UKFax: +44 1865 272595
__
[EMAIL PROTECTED] mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
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Re: [R] allocating memory in C, not in R
Sigal Blay wrote:
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],
inputVector,
outVector1,
outVector2,
outVector3 )
for(i=0;iroof;i++) {
RoutVector1[i] = outVector1[i];
RoutVector2[i] = outVector2[i];
}
return;
}
Well, you could read Writing R Extensions (Section 4.8). Your function
will have to change significantly, though. I would create a list within
the C-function (called val below) and populate the RoutVectors with it.
(I can't remember whether you'll need more than #include R.h. Again, I
direct you to the documentation.)
SEXP myFunction(SEXP argv, SEXP inputVector) {
SEXP val;
PROTECT(val = allocVector(VECSXP, 3));
/* some code you'll have to write */
UNPROTECT(1);
return val;
}
# in R
RoutVectors - .Call(myFunction, argv, inputVector)
--sundar
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, [EMAIL PROTECTED]
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, UKFax: +44 1865 272595
__
[EMAIL PROTECTED] mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
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