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GGL: cartesian_to_spherical_equatorial2 conversion returning nan and not returning false (failed)
by David Doria 25 Sep '12

25 Sep '12

Using this: #include <boost/geometry/geometry.hpp> #include <iostream> int main() { namespace bg = boost::geometry; // bg = 'B'oost 'G'eometry namespace cs = bg::cs; // cs = 'C'oordinate 'S'ystem typedef bg::model::point<long double, 3, cs::cartesian> CartesianType; CartesianType cartesian(-6.89, -1.61, -1.64); // (theta, phi) typedef bg::model::point<long double, 2, cs::spherical<bg::degree> > SphericalType; SphericalType spherical; bg::strategy::transform::from_cartesian_3_to_spherical_equatorial_2<CartesianType, SphericalType> strategy; bg::transform(cartesian, spherical, strategy); std::cout << "cartesian: " << bg::dsv(cartesian) << std::endl << "spherical: " << bg::dsv(spherical) << std::endl; return 0; } I am getting the second coordinate of 'spherical' equal to 'nan'. I stepped through the Boost code, and got to this in strategy_transform.hpp: template <typename P, typename T> inline bool cartesian_to_spherical_equatorial2(T x, T y, T z, P& p) { assert_dimension<P, 2>(); set_from_radian<0>(p, atan2(y, x)); set_from_radian<1>(p, asin(z)); return true; } Here you see asin(z) . asin() requires the argument to be [-1,1] (http://www.cplusplus.com/reference/clibrary/cmath/asin/) However, this should just be the z component of any Cartesian point right? Is there some restriction on the input Cartesian point to cartesian_to_spherical_equatorial2 (and hence the from_cartesian_3_to_spherical_equatorial_2 strategy)? I see a restriction on from_cartesian_3_to_spherical_polar_2: \note If x,y,z point is not lying on unit sphere, transformation will return false but I don't see the same restriction on from_cartesian_3_to_spherical_equatorial_2. Additionally, it doesn't seem to just be a missing comment because the transform() call actually returns true even though this point is not on the unit sphere. If I normalize the point and call the function: CartesianType cartesian(-0.94862, -0.22167, -0.22580); The conversion seems to work successfully, and the call still returns true. Any thoughts? Is this a bug? If not, why is the function not returning false? And better, shouldn't this condition have at least an assertion (i.e. if the norm != 1, then return false or throw)? Thanks, David

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[Fusion] BOOST_FUSION_ADAPT_STRUCT with templated member
by Nevin Liber 25 Sep '12

25 Sep '12

The following piece of code: #include <boost/fusion/include/adapt_struct.hpp> template<int a, int b> struct AB {}; BOOST_FUSION_ADAPT_STRUCT( , Silly, (AB<2,3>, ab)) fails with: main.cpp:8:15: error: macro "BOOST_FUSION_ADAPT_STRUCT" passed 3 arguments, but takes just 2 main.cpp:6:1: error: 'BOOST_FUSION_ADAPT_STRUCT' does not name a type I am assuming this is because the preprocessor splits line 8 into 'AB<2', '3>', 'ab'. How do I work around this? Regards, -- Nevin ":-)" Liber <mailto:nevin@eviloverlord.com> (847) 691-1404

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b2 build problem: fatal error C1189: #error : "This is a GCC specific test case"
by Gunther Laure 25 Sep '12

25 Sep '12

Hi guys! I am getting a build error during build configuration using Visual Studio 2010: ...found 25 targets... ...updating 3 targets... compile-c-c++ C:\Users\glaure\SvnProject\SW_APP\3rdparty\test\boost\bin.v2\libs\regex\build\msvc-10.0\debug\address-model-64\threading-multi\has_icu_test.obj has_icu_test.cpp libs\regex\build\has_icu_test.cpp(12) : fatal error C1083: Cannot open include file: 'unicode/uversion.h': No such file or directory And more important: compile-c-c++ C:\Users\glaure\SvnProject\SW_APP\3rdparty\test\boost\bin.v2\libs\math\config\msvc-10.0\debug\address-model-64\threading-multi\has_gcc_visibility.obj has_gcc_visibility.cpp libs\math\config\has_gcc_visibility.cpp(7) : fatal error C1189: #error : "This is a GCC specific test case". The error is only reproduceable when i am using the --build-dir option of b2. Example: b2.exe -j8 install --build-dir=C:/boost_test --libdir=C:/boost_lib/release address-model=64 --prefix=C:/boost --without-python link=shared threading=multi variant=release Of course boost builds successfully, but the problem is that Visual Studio thinks that the build failed. These checks are not done if you build boost within the source tree. Currently I am using boost 1.50 Bye Gunther

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Boost.Serialization and ordering of multimap elements with the same key
by Jeremiah Willcock 25 Sep '12

25 Sep '12

At least in C++11, std::multimap is required to be stable for elements with the same key. However, serializing and then deserializing a multimap with Boost.Serialization can change the order of elements with the same key to be different than their order in the input multimap. Would it be possible to change multimap deserialization (since serialization appears to preserve the order already) to ensure that the output multimap exactly matches the input one? Thank you. -- Jeremiah Willcock

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boost::graph find the cycle
by tolik levchik 24 Sep '12

24 Sep '12

The following code http://ideone.com/MbvUI outputs 'false', why?

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compilation problems on spirit::karma
by Erik Thiele 24 Sep '12

24 Sep '12

Hello in the attachment there is a single c++ file. on debian squeeze with g++ (Debian 4.4.5-8) 4.4.5 it compiles. debian standard libboost1.42-dev is installed. if you run the program: erik@ludwig:~/allesfresser/karma_problem$ ./a.out ruleSetModal(subCall(projectMemberIdentifier(siemensAltNumber=100, fanucNumber=0, name=)) erik@ludwig:~/allesfresser/karma_problem$ that's the required behaviour. now on new system with g++ (Debian 4.7.1-7) 4.7.1, and libboost1.49-dev, it does not compile. a short excerpt of the enormously long chain of error message: problem.cpp:254:5: required from ‘astGenerate<OutputIterator>::astGenerate() [with OutputIterator = std::back_insert_iterator<std::basic_string<char> >]’ problem.cpp:307:56: required from here /usr/include/boost/spirit/home/support/attributes.hpp:519:28: error: cannot convert ‘const boost::variant<astProjectMemberIdentifier, astErikNcBohrPlanSenk>’ to ‘boost::spirit::traits::attribute_size<boost::optional<boost::variant<astProjectMemberIdentifier, astErikNcBohrPlanSenk> >, void>::type {aka unsigned int}’ in return if you remove the rule in line 254 (ruleSetModal = "ruleSetModal(" << -ruleSubCall << ')';), then the program will compile. but it will output nothing of course. i need this line. it worked all the times and now after update it does not work. honestly i do not understand the long chain of error message. i checked with boost 1_51_1 with the same not working result. also with clang++ compiler it does not work with the same error message. maybe someone on the list can enlighten me why this does not compile anymore. Thanks Erik

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[graph][heap][coroutine] interruptable dijkstra shortest path function
by Alex Hagen-Zanker 23 Sep '12

23 Sep '12

Hi, A few months ago I posted here to gauge interest for an interruptable and resumable version of the dijkstra_shortest_path algorithm. The initial response was positive, but Jeremiah considered the proposed solution lacking compared to an algorithm object model that inverts the control over the algorithm, Additional to my original solution, I now have two implementations of the algorithm object model. 1. Visitor based interruption. This is my original approach. It separates the algorithm into an init and main function. The main function asks the visitor if it should be halted afer each iteration. After halting, the main function can be used to resume the calculation. auto dijkstra = make_dijkstra_object(graph, named_parameters); dijkstra.init_from_sources(sources); dijkstra.expand( interruptor); dijkstra.expand( other_interruptor); auto distance_map = dijkstra.get<vertex_distance_t>(); auto color_map = dijkstra.get<vertex_color_t>(); 2. Algorithm object implementation. This was suggested by Jeremiah. The algorithm object iterates from control point to control point in the algorithm. Giving at each stop access to the intermediate results of the algorithm. The two implementations are a) Using the [Coroutine] library that is currently under review to step in and out of the function. b) Fragmenting the function into many subfunctions that are chained together and the other works by fragmenting the original algorithm into a number of small interlinked functions starting at one control point and returning at the next. The interface of a and b is exactly the same and it works like this: auto dijkstra = make_dijkstra_object(graph, sources, named_parameters); while(dijkstra.next() ) { control_point cp = dijkstra.get_control_point(); vertex u = dijkstra.get_u(); auto distance_map = dijkstra.get<vertex_distance_t>(); if(cp == cp_finish_vertex && get(distance_map, u) > 42) { cout << "far enough" << endl; break; } } auto distance_map = dijkstra.get<vertex_distance_t>(); The algorithm object offers most flexibility for interweaving multiple searches. The visitor based solution on the other hand is more efficient. The latter has no loss in performance compared to the existing dijkstra functions. The coroutine algorithm object was extremely easy to implement but it is not very efficient. Does anybody have a suggestion how that can improve? Besides these interruptable and resumable shortest path searches, there are a few more advantages to the implementation. a. All dijkstra parameters are bundled in a light-weight dijkstra_state object that is returned by algorithms, giving direct access to all results of the algorithm, for instance: auto dijkstra_state = dijkstra_shortest_paths(graph, sources, no_named_parameters() ); auto distance_map = dijkstra_state.get<vertex_distance_t>(); b. Named parameters (old style) are also used for the priority queue and the color map c. Boost.Heap mutable queues can be used with Boost.Graph via the named parameter interface. It doesn't help performance now, but may be a good base for experimentation. d. Separation of the dijkstra shortest path algorithm in init and main function makes it easier to provide custom initialization. For instance: multiple sources or only re-initializing changed vertices Can anybody use this? The latest version is here: http://people.pwf.cam.ac.uk/ahh34/dijkstra.zip Kind regards, Alex p.s. below are timings for a large graph: bimba_6M.obj... 2090 ms. Boost Graph Library 2121 ms. With interruption visitor 5601 ms. With Coroutine(*) 2621 ms. With fragmented functions (*) 2840 ms. With Boost.Heap (*) halting at all control points of the dijkstra visitor

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transform_iterator and c++11 lambda expression
by MM 22 Sep '12

22 Sep '12

hello it would be great to be pass transform_iterator( my_iterator, []( reference ) { return /// something } ); directly to STL algorithms. Currently, one needs to define separately the unarfy function as far as i could see MM

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[Interprocess] Different shared memory locations in Windows
by Aaron_Wright＠selinc.com 21 Sep '12

21 Sep '12

I'm attempting to share memory between two services on a Windows Server 2008 Core box. One service is postgres running as a user created just for that purpose, and the other service is my application running as the Local System user. The issue I'm seeing is that it seems that the two services do not agree on the location of the shared memory files. The postgres service is looking at "C:\Users\<user>\AppData\Local\Temp\boost_interprocess", while my application is looking at "C:\Windows\TEMP". Diving into the code I found that it first tries to use the value of a registry key, "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders\Common AppData", however this key doesn't exist in Windows Server 2008 R2 Core, presumably because there is no explorer.exe running on the box, and thus, no shell folders under it. When that fails, the code attempts to use the TMP environment variable, however that is dependent upon the environment that the user has setup, so the TMP variable is not guaranteed to be the same across users. Indeed in my case the TMP variable for the Local System user was "C:\Windows\TEMP", while the TMP variable for the other user was in its user folder. I'm not sure what the correct answer here is, but I have some ideas: -- The "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders\Common AppData" registry key seems to exist for Windows XP, Windows Server 2008 R2 Core, and Windows 7. And according to TechNet, "The entries that appear in user User Shell Folders take precedence over those in Shell Folders." So maybe that registry key should be used instead. -- Use the ALLUSERESPROFILE variable, which is "C:\Documents and Settings\All Users" on Windows XP, and "C:\ProgramData" on Windows Server 2008 R2 Core and Windows 7. The TMP variable seems to be different for every user. -- Provide a way to tell the library what directory to use. (This doesn't exist does it?) Or hint at what library to use. -- Can/Should the code assert when the folder chosen contains a user name. Might be impracticable, but sure helpful. --- Aaron Wright

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Re: [Boost-users] chaining functions input output
by MM 21 Sep '12

21 Sep '12

great, this is not blocking in my case, as I have written a 3rd function that merges the implementation of the 2 functions that are provided to me with matching results, and therefore avoiding the need for intermediate storage. I can move to your solution in a few months there are 10million entries so it's worth the trouble thanks

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