This looks like a copy and paste mistake. I can definitely see this line on the slide 57: RMatrix<double> output;
Anyway, the example is there: http://gallery.rcpp.org/articles/parallel-matrix-transform/ <http://gallery.rcpp.org/articles/parallel-matrix-transform/> Romain > Le 31 mai 2017 à 12:42, f.k...@mailbox.org a écrit : > > Thanks Romain, > > this error is fine now, however, now I run into new… > I took the example code from this > <http://dirk.eddelbuettel.com/papers/rcpp_rfinance_may2015.pdf> presentation > of Dirk > > > > Rcpp::sourceCpp("src/par_example.cpp") > par_example.cpp:26:21: error: member initializer 'output' does not name a > non-static data member or base class > : input(input), output(output) {} > ^~~~~~~~~~~~~~ > par_example.cpp:31:5: error: use of undeclared identifier 'output' > output.begin() + begin, > ^ > 2 errors generated. > make: *** [par_example.o] Error 1 > > > Hope this is as easily solved as the before error. > > Cheers, Franz > > > > >> On 31 May 2017, at 12:26, Romain Francois <rom...@r-enthusiasts.com >> <mailto:rom...@r-enthusiasts.com>> wrote: >> >> You can add this somewhere on top of your cpp file >> >> // [[Rcpp::depends(RcppParallel)]] >> >> Romain >> >>> Le 31 mai 2017 à 12:22, f.k...@mailbox.org <mailto:f.k...@mailbox.org> a >>> écrit : >>> >>> Hi all, >>> >>> I am very new to Rcpp and I wrote a function which I now want to >>> parallelize. >>> The function is working fine, and is much faster than in R, however, it >>> really is slow for bigger datasets. >>> >>> Since the function is running I don’t need to explain what it does, >>> however, it is has >>> 3 nested for loops. It loops through columns and within each column if >>> loops through the rows and in a third loop produces pair comparisons… >>> >>> So the parallelisation should parallelize the column loop. >>> >>> I found the RcppParallel package and for the beginning wanted to run on of >>> the example to understand the >>> workflow first. However, I already have issues running the code below: >>> >>> following is sourced with: Rcpp::sourceCpp("src/par_example.cpp") >>> However, I get the error: >>> >>> par_example.cpp:6:10: fatal error: 'RcppParallel.h' file not found >>> #include <RcppParallel.h> >>> ^ >>> 1 error generated. >>> make: *** [par_example.o] Error 1 >>> >>> I would much appreciate if someone could give me a start with this! >>> >>> Cheers, >>> Franz >>> >>> >>> >>> #include <Rcpp.h> >>> >>> using namespace Rcpp; >>> #include <cmath> >>> #include <algorithm> >>> #include <RcppParallel.h> >>> >>> // [[Rcpp::export]] >>> NumericMatrix matrixSqrt(NumericMatrix orig) { >>> // allocate the matrix we will return >>> NumericMatrix mat(orig.nrow(), orig.ncol()); >>> // transform it >>> std::transform(orig.begin(), orig.end(), mat.begin(), ::sqrt); >>> // return the new matrix >>> return mat; >>> } >>> >>> >>> using namespace RcppParallel; >>> struct SquareRoot : public Worker { >>> const RMatrix<double> input; >>> // source matrix RMatrix<double> output; // destination matrix >>> // initialize with source and destination >>> SquareRoot(const NumericMatrix input, NumericMatrix output) >>> : input(input), output(output) {} >>> // take the square root of the range of elements requested >>> void operator()(std::size_t begin, std::size_t end) { >>> std::transform(input.begin() + begin, >>> input.begin() + end, >>> output.begin() + begin, >>> ::sqrt); >>> } >>> }; >>> >>> // [[Rcpp::export]] >>> NumericMatrix parallelMatrixSqrt(NumericMatrix x) { >>> // allocate the output matrix >>> NumericMatrix output(x.nrow(), x.ncol()); >>> // SquareRoot functor (pass input and output matrixes) >>> SquareRoot squareRoot(x, output); >>> // call parallelFor to do the work >>> parallelFor(0, x.length(), squareRoot); >>> // return the output matrix >>> return output; } >>> >>> >>> >>> _______________________________________________ >>> Rcpp-devel mailing list >>> Rcpp-devel@lists.r-forge.r-project.org >>> <mailto:Rcpp-devel@lists.r-forge.r-project.org> >>> https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel >>> <https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel> >
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