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SVG Graphics - to be supported by IE9 - Boost GSoC project?
by Paul A. Bristow 16 Apr '10

16 Apr '10

Some may remember that Jake Voytko worked on a SVG graphic plotting package during a 2007 GSoC - dubbed Boost.Plot. In July 2009, I announced that this was available for people to 'try out' - it seems in a usable condition. Although several people made some kind remarks about it, I sensed that the 'killer' feature was using SVG SVG was *NOT supported 'out-of-the-box'* by Microsoft IE (including 8, to my surprise, and disappointment). It now seems that Microsoft have 'seen' the light' and promise that IE 9 will provide good and portable support for SVG. http://blogs.msdn.com/ie/archive/2010/03/18/svg-in-ie9-roadmap.aspx They have finally realised the 'small is beautiful' applies to graphics - especially now that many are being displayed on phones with limited speed links. SVG graphics need a tiny amount of code, especially when compressed, and can be expanded without 'going all pixelly'. Boost.Plot is special in that it is in C++ and it has a Boost license. It allows you to add just a few lines of code to the end of your C++ program to take data from any STL container (all or part) and produce a plot as a Scale Vector Graph (.svg) file. So it is already suited to sending near real-time plots to phones. BUT while Boost.Plot provides zillions of functions to TechniColor your XY plots, it doesn't do much to help produce other displays - even things as simple as pie charts. And the underlying SVG interface functions are perhaps rudimentary. So I wonder if there is any enthusiasm for a Google Summer of Code project for NEXT summer 2011 to get this into a reviewable state? (Sadly I think we have just missed GSoC for this year). Paul PS A few demo plots are attached for your amusement. The latest version is available on SVN https://svn.boost.org/svn/boost/sandbox/SOC/2007/visualization/ Docs are available to build as html and pre-built as pdf (patience - 6 Mbyte!) https://svn.boost.org/svn/boost/sandbox/SOC/2007/visualization/libs/svg_plot /doc/pdf/svg_plot.pdf or http://tinyurl.com/coqlbg (or ask if you want zips instead). --- Paul A. Bristow Prizet Farmhouse Kendal, UK LA8 8AB +44 1539 561830, mobile +44 7714330204 pbristow(a)hetp.u-net.com

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Has anyone successfully used boost with gcc 4.5.0 (mingw) ?
by Mauricio Gomes 16 Apr '10

16 Apr '10

Hi, My code was running fine with gcc 4.4.0, Mingw and boost. I changed to gcc. 4.5.0 and though it compiles okay it crashes when I try to run my tests. Has anyone successfully used boost with gcc 4.5.0 (mingw) ? Thanks, -- Mauricio Gomes

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[program_options] printing options summary
by Stanisław Findeisen 16 Apr '10

16 Apr '10

[This question is about Boost.program_options library.] When I want to print options summary (e.g., for --help) I do this: cout << optionsDesc where optionsDesc is: boost::program_options::options_description optionsDesc; The output is correct, but how to format it? It looks bad: --mode arg [must be set] [........] mode: 'f' to gener ate file, or 'x' to fix file, or 'p' to gen erate ... Option descriptions are too narrow, and some words are broken right in the middle. (There is a big gap here between "mode" and its description because other option names are quite long.) It would be nice to be able to print wider option descriptions or maybe option descriptions *below* option names and somewhat indented (instead of to the right). Are there any formatting options? Thanks! STF

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[Website] The link to the Wiki points to Trac
by Sébastien Dumont 16 Apr '10

16 Apr '10

Hi, On the Boost homepage at http://www.boost.org/, the link to the Wiki on the right instead points to Trac, is it the intended behaviour? Thanks, Sebastien

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[Iostreams] Problem with filtering_istream and gzip_decompressor with 64bit
by peterbarnabus 16 Apr '10

16 Apr '10

Hi, I am trying to use the iostream gzip filters, and have run into some problems using them with 64bit compilers. I am using OSX 10.6 and my code works just fine with apples gcc-4.2 compilers in both 32 and 64 bit mode. However, with gcc4.4 or gcc4.5 compilers, it runs only in 32bit mode and crashes in 64bit mode. Has anyone run into this issue? Is it a problem with how I am using the iostream library? Here is the code to reproduce: $ g++-mp-4.4 -m64 -g -O0 -o test_iostreams.4.4-64 test_iostreams_64.C -I/opt/local/include/boost/ -I/opt/local/include/ -L/opt/local/lib/ -lboost_iostreams-mt If I run the 64bit executable I get this message (for the 32bit it just echo's the file correctly): $ ./test_iostreams.4.4-64 test_iostreams.4.4-64(38367) malloc: *** error for object 0x100164dc0: pointer being freed was not allocated *** set a breakpoint in malloc_error_break to debug ^CAbort trap #include <iostream> #include <fstream> #include <string> #include <sstream> #include <boost/iostreams/filtering_stream.hpp> #include <boost/iostreams/filter/gzip.hpp> #include <boost/iostreams/device/file.hpp> namespace io = boost::iostreams; using namespace std; void test() { string filename("/tmp/g.dot.gz"); istream *ifs = new io::filtering_istream(); ((io::filtering_istream *) ifs)->push(io::gzip_decompressor()); ((io::filtering_istream *) ifs)->push(io::file_source(filename)); string str; while( std::getline((*ifs), str) ) { std::cout << "read line : " << str << std::endl; } } int main(int argc, char **argv) { test(); return 0; }

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Spirit and on_error
by Michele Caini 16 Apr '10

16 Apr '10

Hi all, someone can explain to me how to use, if it's possible, on_error error handler? I'd like to throw an exception reporting error data, because I'm using spirit in a Qt-based application, and my idea is to catch exception on upper level to pop-up a messagebox or something like that. I start from documentation example, here: on_error<fail> ( xml , std::cout << val("Error! Expecting ") << _4 // what failed? << val(" here: \"") << construct<std::string>(_3, _2) // iterators to error-pos, end << val("\"") << std::endl ); Trying several possible solution, no one compiles fine. I don't know, really, what I have to do, so please help me!! :-) Thanks in advance, Michele

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[Wiki] Please remove spam on Boost.Build V2/GettingStarted page
by Sébastien Dumont 16 Apr '10

16 Apr '10

Hi, There is some spam on the Boost.Build V2/GettingStarted page in the Boost Wiki (http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl?Boost.Build_…) and I cannot edit it, could someone else please remove it ? It is the three "buy XXX online" links at the bottom of the page, below the link to "Boost.Build V2/MicrosoftVCProjMigration". Thanks, Sebastien

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boost and Compact Framework
by Luigi Seregni 16 Apr '10

16 Apr '10

Hello everybody, I'm developing a wearable gesture recongnition system in which I deal with matrix calculation and signal processing. All software must be developed in C++, so I think that Boost is a good choice for matrix calculation (also for signal processing? for example: FFT, wavelet...). Mainly, I'd like to ask you if Boost libraries are compatible with .NET Compact Framework 3.5. Thanks in advance for your reply. Luigi Seregni

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[date_time] howto determine date format?
by Markus Werle 16 Apr '10

16 Apr '10

Hi! With the code below I try to automagically determine the date format found in input files. I'd expect the code below to find the date format "%d.%m.%Y" for "05.02.2008", but I got surprised by obtaining "%m/%d/%Y". A major pain it is with those dates. Whether my shallow knowledge of locales and imbue or boost::date_time (from boost-1.37.0) is to be blamed is beyond my horizon. I feel like date accepts '.' where I said "expect '/'", so I think this should be changed. I may be wrong. Could you please shed some light on the issue? Thanks, Markus #include <boost/assign/list_of.hpp> #include <boost/date_time/posix_time/posix_time.hpp> #include <boost/date_time/gregorian/gregorian.hpp> #include <boost/date_time/local_time/local_time.hpp> #include <boost/foreach.hpp> #include <boost/algorithm/string.hpp> #include <string> #include <list> inline std::string determine_date_format(std::string const & s) { using namespace boost::assign; using namespace boost::gregorian; std::list<std::string> possible_formats = // TODO: add others here! list_of ("%Y-%m-%d")("%Y/%m/%d")("%m/%d/%Y")("%d.%m.%Y"); bool inform_user = false; BOOST_FOREACH(std::string const & format, possible_formats) { if (inform_user) { std::cout << "Trying format '" << format << "' ..." << std::endl; } try { date_input_facet * input_facet = new date_input_facet(format.c_str()); std::istringstream iss(s); iss.imbue(std::locale(iss.getloc(), input_facet)); date d(not_a_date_time); iss >> d; if (!iss.fail() && (!d.is_not_a_date())) { return format; } std::cout << "WARNING: date format '" << format << "' does not match '" << s << "'." << std::endl; inform_user = true; } catch(...) { } } std::cout << "WARNING: date format not recognized. " << "Please reconfigure your measurement equipment " << "to ISO standard output!" << std::endl; return ""; } int main() { std::string the_date = "05.02.2008"; std::string format = determine_date_format(the_date); std::cout << the_date << " has date-time-format " << format << std::endl; return 0; }

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Monitoring Active Threads in Boost
by Weide Zhang 16 Apr '10

16 Apr '10

Does any one has experience in the monitoring number of currently running active threads ? We used boost thread and allocate around 100 threads. We are interested to know at certain time point, how many threads are actively serving. Thanks a lot for the help, Weide

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