Dear all,
I am puzzled at the behaviour of is.loaded() when a dyn.load() call to a a
FORTRAN shared library is included in a file to be sourced.
A reproducible example is the following:
1. the attached fortran subroutine try_it.f90 performs a summation of the
elements of a REAL*8 vector
compile with
gfortran try_it.f90 -shared -s -otry_it.dll
2. create a file to be sourced (see the attached try_it.R) containing the
following commands:
BEGIN try_it.R ************************************
dyn.load("try_it.dll");
try.it <- function(X){
N <- length(X);
S <- .Fortran("try_it_",as.double(X),as.integer(N),S=as.double(0))$S
return(S)
}
END try_it.R ************************************
3. Switch to R
source("try_it.R")
try.it(1:10)
Error in .Fortran("try_it_", as.double(X), as.integer(N), S = as.double(0))
:
Fortran symbol name "try_it_" not in load table
is.loaded("try_it_")
[1] TRUE
try.it(1:10)
[1] 55
it looks like is.loaded() triggers the loading, inserting
is.loaded("try_it_")in
the file try_it.R does the trick but
is this behaviour expected?
Thank you,
Regards
Simone
R.version
_
platform i386-pc-mingw32
arch i386
os mingw32
system i386, mingw32
status
major 2
minor 4.1
year 2006
month 12
day 18
svn rev 40228
language R
version.string R version 2.4.1 (2006-12-18)
--
______________________________________________________
Simone Giannerini
Dipartimento di Scienze Statistiche "Paolo Fortunati"
Universita' di Bologna
Via delle belle arti 41 - 40126 Bologna, ITALY
Tel: +39 051 2098262 Fax: +39 051 232153
______________________________________________________
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