November 2009 - Boost-users

Re: [Boost-users] covariance calculus via boost::accumulators
by Conoscenza Silente 25 Nov '09

25 Nov '09

Hi All I would like to calculate the covariance of 2 variables. I found that in Boost there is boost::accumulators and the Statistical Accumulators Library that looks good to me. Covariance is a measure of how much two variables change together, but in the example given by boost ( I am guessing) I see only an example for one variable. I did not really understand how to setup the accumulators for 2 or more variables. What role plays the covariate here and where to pick up or feed the values for the second variable? Thanks to all accumulator_set<double, stats<tag::covariance<double, tag::covariate1> > > acc; acc(1., covariate1 = 2.); acc(1., covariate1 = 4.); acc(2., covariate1 = 3.); acc(6., covariate1 = 1.);

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Re: [Boost-users] binary serialization, what's missing
by Avi Bahra 25 Nov '09

25 Nov '09

Reproduced the crash with binary serialization. Program received signal SIGSEGV, Segmentation fault. #0 0x08082c1f in boost::archive::detail::basic_oarchive_impl::save_pointer () #1 0x08081f16 in boost::archive::detail::basic_oarchive::save_pointer () #2 0x08076ad8 in boost::archive::detail::save_pointer_type<boost::archive::binary_oarchive, RepeatBase*>::polymorphic<RepeatBase>::save (ar=@0xbfd58428, t=@0x80bbd38) at /var/tmp/ma0/boost/boost_1_39_0/boost/archive/detail/oserializer.hpp:408 #3 0x08076b04 in boost::archive::detail::save_pointer_type<boost::archive::binary_oarchive, RepeatBase*>::save<RepeatBase> (ar=@0xbfd58428, t=@0x80bbd38) at /var/tmp/ma0/boost/boost_1_39_0/boost/archive/detail/oserializer.hpp:428 #4 0x08076b6c in boost::archive::detail::save_pointer_type<boost::archive::binary_oarchive, RepeatBase*>::invoke (ar=@0xbfd58428, t=0x80bbd38) at /var/tmp/ma0/boost/boost_1_39_0/boost/archive/detail/oserializer.hpp:457 #5 0x08076b98 in boost::archive::save<boost::archive::binary_oarchive, RepeatBase*> (ar=@0xbfd58428, t=@0x80b9738) at /var/tmp/ma0/boost/boost_1_39_0/boost/archive/detail/oserializer.hpp:506 #6 0x08076bcc in boost::archive::detail::common_oarchive<boost::archive::binary_oarchive>::save_override<RepeatBase* const> (this=0xbfd58428, t=@0x80b9738) at /var/tmp/ma0/boost/boost_1_39_0/boost/archive/detail/common_oarchive.hpp:64 #7 0x08076bfd in boost::archive::basic_binary_oarchive<boost::archive::binary_oarchive>::save_override<RepeatBase*> (this=0xbfd58428, .... In doing this I have noted. o creating small trivial cases seemed to work. o when I combined the test case files to a single file, it worked In trying to create the test case I figured out what caused the crash, Basically I had included text archive in all the compilation units but the binary archive _only_ in the file where I was outputting to the disk. When I included the binary archive in _all_ the compilation units that were being serialized, the test worked. I am not sure how common this case is, but gcc compiler/linker gave no warnings Maybe this need to be added as a gotcha in the documentation? Best regards, Ta, Avi

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[Serialization] Serialize shared_ptr compile error
by elizabeta petreska 25 Nov '09

25 Nov '09

Hello I can't compile my simple project for serializing shared_ptr . I read the archives and google it and still can't compile it :) I am doing the following : /////A.h #pragma once #include <boost/archive/xml_iarchive.hpp> #include <boost/archive/xml_oarchive.hpp> #include <boost/serialization/nvp.hpp> #include <boost/serialization/shared_ptr.hpp> class A { public: A(int k):mk(k) { } A() { } template<class Archive> void save(Archive & ar, const unsigned int version) const { using boost::serialization::make_nvp; ar & BOOST_SERIALIZATION_NVP(mk); } template<class Archive> void load(Archive & ar, const unsigned int version) { using boost::serialization::make_nvp; ar & BOOST_SERIALIZATION_NVP(mk); } BOOST_SERIALIZATION_SPLIT_MEMBER() int mk; }; BOOST_SERIALIZATION_SHARED_PTR(A) ///func.cpp #include "A.h" void func() { std::ofstream ofs(L"C:\\boostarchiveSharedPtr.xml"); std::ifstream ifs(L"C:\\boostarchiveSharedPtr.xml"); boost::shared_ptr<A> bPtr(new A(13)); { using boost::serialization::make_nvp; boost::archive::xml_oarchive oa(ofs); oa & BOOST_SERIALIZATION_NVP(bPtr); } boost::shared_ptr<A> rbPtr; { using boost::serialization::make_nvp; boost::archive::xml_iarchive ia(ifs); ia & BOOST_SERIALIZATION_NVP(rbPtr); } } And I am getting the following compile time error : 'boost::mpl::assertion_failed' : cannot convert parameter 1 from 'boost::mpl::failed ************boost::serialization::is_wrapper<T>::* ***********' to 'boost::mpl::assert<false>::type' D:\main\dev\sdk\libs\boost\inc\boost-1_38\boost\archive\basic_xml_oarchive.hpp 88 The comment about the erroir says : // If your program fails to compile here, its most likely due to // not specifying an nvp wrapper around the variable to // be serialized. I can't understand what does it mean, since I have BOOST_SERIALIZATION_NVP when writing /reading to the archive

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Re: [Boost-users] binary serialization, what's missing
by Avi Bahra 25 Nov '09

25 Nov '09

Ok I have managed to reproduce the crash in binary archive in a set of standalone files, i.e 8 files. But last time I included a tar, it got stripped. Would it be ok to just embed the file in the email or is there some other mechanism to attach file/tar files ? Best regards, Ta, Avi

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handling unicode strings / encodings?
by Maróy Ákos 25 Nov '09

25 Nov '09

Hi, I wonder what the state of handling unicode strings is in C++ / with boost? I've found some references to the codecvt<> feature, and also I've found utf8_codecvt_facet among the boost sources, but I can't really make it work. what I would need is to handle strings based on the whole unicode representation, and to encode them to UTF-8 and back. is there anything related in boost? Akos

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[GIL] Help on rgba 10 bits views
by Eloi Du Bois 25 Nov '09

25 Nov '09

Hi, I would like to know how can I create a 10 bits view that makes it possible to use interleaved_view. My data are described as follow: R10G10B10A10;R10G10B10A10;R10G10B10A10;R10G10B10A10;..... You understand easily that a rgba pixel is stored on 40 bits... I tried this: typedef bit_aligned_pixel_reference<uint64_t, > mpl::vector4_c<uint16_t, 10, 10, 10, 10>, rgba_layout_t, true> > rgba10101010_ref_t; > // A mutable iterator over RGB101010 pixels > typedef bit_aligned_pixel_iterator<rgba10101010_ref_t> > rgba10101010_ptr_t; > typedef std::iterator_traits<rgba10101010_ptr_t>::value_type > rgba10101010_pixel_t; > // View type from pixel type > typedef view_type_from_pixel<rgba10101010_pixel_t>::type > rgba10101010_view_t; > rgba10101010_view_t src; > But it does a mess with my pixels... (and makes it impossible to use copy_and_convert_pixels(src, rgba16_view_t(view(img))); ) If anyone could help me, that would be great ! Thank you by advance, Eloi.

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binary serialization, what's missing
by Avi Bahra 25 Nov '09

25 Nov '09

I have a complex tree structure. When this is serialized with text archive all is well. (i.e on linux/gcc) However when I attempt to use the binary archive, it crashes when trying to serialize a base pointer ? I though that text and binary were interchangeable, have I missed something or is serialization via base pointer not implemented in binary ? Any help appreciated. Best regards, Ta, Avi

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Re: [Boost-users] binary serialization, what's missing
by Avi Bahra 25 Nov '09

25 Nov '09

Jeff Wrote: >Are the underlying streams opened as binary? > >Jeff Yes, This is how I save, the the restore is analogous. Using boost 1.39 void save(bool binary) const { if (binary) { std::ofstream ofs( fileName_.c_str(), ios::binary ); boost::archive::binary_oarchive oa( ofs ); oa << *this; } else { std::ofstream ofs( fileName_.c_str() ); boost::archive::text_oarchive oa( ofs ); oa << *this; } } Ok I was trying eventually to use the portable binary archive, however I suspect that would crash as well. I will try to create a standalone program that shows the crash using the binary archive first. Best regards, Ta, Avi

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Boost Server Downtime Wednesday Morning
by Doug Gregor 25 Nov '09

25 Nov '09

The main Boost server will be down for a short time Wednesday, November 25th (tomorrow!) from 8:00AM Eastern time to 8:30AM Eastern time to replace some memory. This outage will affect most of Boost's services, including the mailing lists, boost.org web server, and Boost Subversion repository (including the sandbox). Sorry for the inconvenience! - Doug

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issues with setting properties on reverse graph
by Mangal 24 Nov '09

24 Nov '09

Trying to set graph properties on reverse graph does not seem to be working. I am using boost 1.40.0 A simple program where we set graph_name to "graph" on a reverse graph does not work int main() { using namespace boost; using std::string; typedef adjacency_list<vecS, vecS, directedS,no_property, property<edge_index_t, int>, property<graph_name_t, string> > graph_t; typedef reverse_graph<graph_t> reverse_graph_t; graph_t g; reverse_graph_t sg = reverse_graph_t(g); std::string Name = "graph"; set_property(sg, graph_name, Name) ; std::cout << "name: " << get_property(sg, graph_name) << std::endl; return 1; } Name comes out to be empty in this case. any ideas??? -- View this message in context: http://old.nabble.com/issues-with-setting-properties-on-reverse-graph-tp263… Sent from the Boost - Users mailing list archive at Nabble.com.

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