On Feb 20, 2013, at 1:46 AM, Dirk Eddelbuettel <e...@debian.org> wrote:
> > On 20 February 2013 at 01:15, Yan Zhou wrote: > | Hi Dirk, > > I see nothing Rcpp-specific here. It's more about how to avoid ambiguity > within C++. Might make a good question for the C++ tag on StackOverflow. Yes, exactly. The problem itself is nothing Rcpp specific but the operator implementation was copied directly from Rcpp's proxy header. I will ask it on Stack later. > > Dirk > > | On Feb 20, 2013, at 1:11 AM, Dirk Eddelbuettel <e...@debian.org> wrote: > | > | > > | > On 19 February 2013 at 23:46, Ken Williams wrote: > | > | > From: Dirk Eddelbuettel [mailto:e...@debian.org] > | > | > You are relying on an implicit conversion here to make df(.,.) a > double. The > | > | > compiler tells you that it is trying sugar operators. Sugar is good > to have in > | > | > Rcpp, but occassionally there is a cost. This may be one of those > times. > | > | > > | > | > Try > | > | > > | > | > double a = df(j,i); > | > | > double b = df(j,last_i); > | > | > if (fabs(a - b) > thresh) { > | > | > > | > | > and see if that works. > | > | > | > | Unfortunately no, I get a similar error when I try that: > | > | > | > | window.cpp:68:24: error: conversion from 'Rcpp::Vector<19>::Proxy {aka > Rcpp::internal::generic_proxy<19>}' to 'double' is ambiguous > | > | window.cpp:68:24: note: candidates are: > | > | > C:/mybin/R/R-2.15.2/library/Rcpp/include/Rcpp/vector/string_proxy.h:273:4: > note: Rcpp::internal::generic_proxy<RTYPE>::operator int() const [with int > RTYPE = 19] > | > | > C:/mybin/R/R-2.15.2/library/Rcpp/include/Rcpp/vector/string_proxy.h:272:4: > note: Rcpp::internal::generic_proxy<RTYPE>::operator bool() const [with int > RTYPE = 19] > | > | > C:/mybin/R/R-2.15.2/library/Rcpp/include/Rcpp/vector/string_proxy.h:267:26: > note: Rcpp::internal::generic_proxy<RTYPE>::operator U() const [with U = > double, int RTYPE = 19] > | > > | > Maybe try std::fabs() instead of fabs() ? > | > > | > That is one of the reasons I do not like a global 'using namespace Rcpp' > in > | > my code. Explicit namespaces are, well, explicit. > | > > | > Dirk > | > | > | > | > | > | > > | > | > Not every conceivable operation is implemented in Rcpp, > | > | > | > | Of course. =) > | > | > | > | > but we are always > | > | > open to patches to make it more complete. > | > | > | > | If I can get myself up to speed with my understanding, I'll be happy to > contribute what I can. > | > | > | > | -Ken > | > | > | > | ________________________________ > | > | > | > | CONFIDENTIALITY NOTICE: This e-mail message is for the sole use of the > intended recipient(s) and may contain confidential and privileged > information. Any unauthorized review, use, disclosure or distribution of any > kind is strictly prohibited. If you are not the intended recipient, please > contact the sender via reply e-mail and destroy all copies of the original > message. Thank you. > | > > | > -- > | > Dirk Eddelbuettel | e...@debian.org | http://dirk.eddelbuettel.com > | > _______________________________________________ > | > Rcpp-devel mailing list > | > Rcpp-devel@lists.r-forge.r-project.org > | > https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel > | > > -- > Dirk Eddelbuettel | e...@debian.org | http://dirk.eddelbuettel.com _______________________________________________ Rcpp-devel mailing list Rcpp-devel@lists.r-forge.r-project.org https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel
