March 2006 - Boost-users - lists.preview.boost.org

Boost::Python core dump
by Dave Steffen 29 Mar '06

29 Mar '06

Hi folks, I've got a Boost::Python compatibility question. Our application is written in python, with a bunch of math stuff written in C++ and access from python via Boost::Python. Having recently rebuilt from scratch, the python code (which formerly worked) now produces an (almost) immediate core dump: ./run_gui.sh: line 3: 25950 Segmentation fault (core dumped) python gui/bntd_gui.py $* GDB is generally unhelpful, but it _looks_ like the problem happens while it's loading shared libraries; that is, the core dump indicates that Python is dying somewhere at the end of the "load shared libraries" stage. Does anybody have any advice? What sorts of things might cause this? Might a mismatch be a compiler-used-for-building-python vs compiler-used-for-building-my-app incompatibility? I'm using python 2.3.3 (built with GCC 3.4.1), and building the C++ code into shared libs with GCC 3.3.1 (not the same!). Any thoughts would be greatly appreciated. Thanks! ---------------------------------------------------------------------- Dave Steffen, Ph.D. Fools ignore complexity. Pragmatists Software Engineer IV suffer it. Some can avoid it. Geniuses Numerica Corporation remove it. ph (970) 419-8343 x27 -- Alan Perlis fax (970) 223-6797 dgsteffen(a)numerica.us

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Re: [Boost-users] [MultiArray] Banded matrix
by Sohail Somani 29 Mar '06

29 Mar '06

Yes, I think this seems to be the case. I read some posts about how multi_array might be extended to support more numerical code. How do you suppose this would be done? > -----Original Message----- > From: Ronald Garcia [mailto:garcia@cs.indiana.edu] > Sent: Wednesday, March 29, 2006 2:10 PM > To: Sohail Somani > Cc: boost-users(a)lists.boost.org > Subject: Re: [MultiArray] Banded matrix > > Hi Sohail, > > You will likely not be able to get this to work correctly. The > multi_array_ref operators rely upon the dense representation of an > array. More likely you will want to use template function that uses > array notation as in: > > template <class Array> > void some_fcn(const Arrray& m); > > ron > > On Mar 29, 2006, at 3:04 PM, Sohail Somani wrote: > > > Well, I'd like to use a banded_matrix *as* a multi_array. > For example: > > > > some_fcn( const multi_array_ref<T,2> & m); > > > > I'd like to pass in an implementation of a multi_array_ref<T,2> > > that is > > optimized to only hold three diagonals of the array (for example). > > > > Should this not be done? :) > > > > Sohail > > > >> -----Original Message----- > >> From: Ronald Garcia [mailto:garcia@cs.indiana.edu] > >> Sent: Wednesday, March 29, 2006 12:01 PM > >> To: Sohail Somani > >> Cc: boost-users(a)lists.boost.org > >> Subject: Re: [MultiArray] Banded matrix > >> > >> Hi Sohail, > >> > >> I'm not clear on what you mean "used as a multi_array_ref". Could > >> you elaborate what you are tryijng to do? > >> > >> ron > >> > >> On Mar 28, 2006, at 1:56 PM, Sohail Somani wrote: > >> > >>> Hi, > >>> > >>> I'd like to continue to use multi array as my array type > >> for numerical > >>> work. I'd like to hear some suggestions on how I could implement a > >>> banded matrix based on multi_array such that it could be used as a > >>> multi_array_ref. The obvious solution is to subclass, have > >> an array of > >>> multi_array<T,1> and overload the indexing operators. > >>> > >>> Are there any gotchas? > >>> > >>> Thanks! > >>> > >>> Sohail > >> > >> > >

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Re: [Boost-users] [MultiArray] Banded matrix
by Sohail Somani 29 Mar '06

29 Mar '06

Well, I'd like to use a banded_matrix *as* a multi_array. For example: some_fcn( const multi_array_ref<T,2> & m); I'd like to pass in an implementation of a multi_array_ref<T,2> that is optimized to only hold three diagonals of the array (for example). Should this not be done? :) Sohail > -----Original Message----- > From: Ronald Garcia [mailto:garcia@cs.indiana.edu] > Sent: Wednesday, March 29, 2006 12:01 PM > To: Sohail Somani > Cc: boost-users(a)lists.boost.org > Subject: Re: [MultiArray] Banded matrix > > Hi Sohail, > > I'm not clear on what you mean "used as a multi_array_ref". Could > you elaborate what you are tryijng to do? > > ron > > On Mar 28, 2006, at 1:56 PM, Sohail Somani wrote: > > > Hi, > > > > I'd like to continue to use multi array as my array type > for numerical > > work. I'd like to hear some suggestions on how I could implement a > > banded matrix based on multi_array such that it could be used as a > > multi_array_ref. The obvious solution is to subclass, have > an array of > > multi_array<T,1> and overload the indexing operators. > > > > Are there any gotchas? > > > > Thanks! > > > > Sohail > >

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[MultiArray] Banded matrix
by Sohail Somani 29 Mar '06

29 Mar '06

Hi, I'd like to continue to use multi array as my array type for numerical work. I'd like to hear some suggestions on how I could implement a banded matrix based on multi_array such that it could be used as a multi_array_ref. The obvious solution is to subclass, have an array of multi_array<T,1> and overload the indexing operators. Are there any gotchas? Thanks! Sohail

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[program-options] windows/dos_style
by Andy 29 Mar '06

29 Mar '06

I am just starting to create a program on windows with command line options. I want it act like most dos based programs do. I have been looking at the enum style_t in cmdline.hpp. It provides a unix_style but there is no dos_style or windows_style. What would a dos_style/windows_style look like? Thanks, Andy

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[date_time] local_time compiler issue
by Prasad Ramanan 29 Mar '06

29 Mar '06

Hi, I get a compiler error when trying to compile the following simple program that includes the boost local_time header file: #include <iostream> #include <fstream> #include <string> #include "boost/date_time/local_time/local_time.hpp" using namespace std; void main() {} The error is: 'syntax error: '<' in the file boost\date_time\tz_db_base.hpp at the following line: 'typedef time_zone_names<charT> time_zone_names;' (this is line 149 of this file) I am using boost version 1.32, and I am using the c++ compiler from Microsoft Visual C++ .NET Version 7.1.3088. Does anyone know what is going on here? I have used boost::gregorian and boost::posix_time before successfully. Thanks for your help, Prasad

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Dynamically creating classed by name?
by Rob Caldecott 29 Mar '06

29 Mar '06

Is there any way that, using Boost, you can dynamically create classes by name, similar to the MFC RUNTIME_CLASS macros? I was hoping that the boost::serialize libs might be able to help with this. For example, I want to be able to do something like: CMyClass* pClass = CREATE_CLASS_BY_NAME("CMyClass"); Can Boost help me to achieve this?

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helppppppppp me please
by Karim Bakir 29 Mar '06

29 Mar '06

Hi, I develop in VC++, I use boost library, I have a problem , I use Multi array It runs very well however I can't to include a boost array as a parameter in a function , the compilation is Ok but at the execution it does nothing. Too I can't declare a private member as boost multi array. With boost I can only return a boost multi array , that is OK . Declare member variabla as a boost multiarray it said extents unexpected for example: class Myclass { public : void maFonction(boost::multi_array<double, 2> res); private : int dim1; int dim2; typedef boost::multi_array<double, 2> boostResultatNearby(boost::extents[dim1][dim2][dim3]) } Can you help me please thanks --------------------------------- Nouveau : téléphonez moins cher avec Yahoo! Messenger ! Découvez les tarifs exceptionnels pour appeler la France et l'international.Téléchargez la version beta.

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[Numeric Conversion] numeric_cast and UDTs
by Scott Meyers 29 Mar '06

29 Mar '06

From a cursory look through the library doc, it appears that it's possible to create a UDT such that numeric_cast will work with it. For example, class int24 { ... }; // for 24-bit ints; must also specialize // std::numeric_limits, create a range // checking policy, etc. int i; ... int24 myInt = numeric_cast<int24>(i); // throws if i's value won't // fit in an int24 short s = numeric_cast<short>(myInt); // throws if myInt's value won't // fit in a short Can somebody who knows this library please tell me if my understanding is correct -- that numeric_cast can be made to work with integral UDTs? Thanks, Scott

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Building boost using the VS2005 ARM cross-compiler?
by Alex Korban 29 Mar '06

29 Mar '06

Hi Has anyone attempted to build boost using the VS2005 ARM cross-compiler? Are all the necessary libraries available in this version of Visual Studio (I know they weren't in EVC4)? How would I go about actually building boost? My understanding is that I need to modify the jam files to use the cross-compiler. Perhaps somebody has already done it? Any help would be greatly appreciated. -- Best regards Alex Korban.

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