Le 29/07/10 03:58, Young-Ju Park a écrit :
Hi all,
I have a question.
How get colnames and rownames in Rcpp method?
attecthed file : RGui.exe capture
my work environment :
R version : 2.11.1
Development Language : VC++
OS : WinXP Pro sp3
Thanks and best regards.
Young-Ju, Park
from Korea
Hi,
This is not a reproducible example, the screenshot is very irrelevant to
the question I think you are asking. I'll reply to what I think you are
asking which is "how to get the colnames of a matrix in Rcpp".
colnames and rownames in R are stored in the "dimnames" attribute of
matrices, so in Rcpp you can access them using the attr member function:
require( inline )
m <- outer(
c( A = 4, B = 5 ),
c( C = 4, D = 5 )
, "+" )
f <- cxxfunction( signature( x_ = "matrix" ), '
NumericMatrix x(x_) ;
List dimnames = x.attr( "dimnames" ) ;
return dimnames[0] ;
', plugin = "Rcpp" )
f( m )
Another way is to invoke the rownames function from inside C++.
f <- cxxfunction( signature( x_ = "matrix" ), '
NumericMatrix x(x_) ;
Function rownames("rownames") ;
return rownames(x) ;
', plugin = "Rcpp" )
f( m )
Does that answer your question ?
Romain
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Romain Francois
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