Re: [Boost-users] multi_array with large dimensions crashes

Subject: Re: [Boost-users] multi_array with large dimensions crashes
From: Pierre-Andre Noel (noel.pierre.andre_at_[hidden])
Date: 2011-08-24 11:39:16

> Is this line correct it get compile errors at this line

>> array_ref_type::size_type xDim(500), yDim(300), zDim(400);

It seems ok to me, and compiles on gcc. However, I am not familiar with
other compilers...

Maybe try to replace it with:

typedef array_ref_type::size_type size_type;
size_type xDim(500);
size_type yDim(300);
size_type zDim(400);

or, if it still does not work:

typedef unsigned int size_type;
size_type xDim = 500;
size_type yDim = 300;
size_type zDim = 400;

Pierre-André

On Wed, Aug 24, 2011 at 11:18 AM, Jothy <jothybasu_at_[hidden]> wrote:

> Thanks very much Pierre.
>
> Is this line correct it get compile errors at this line
>
> array_ref_type::size_type xDim(500), yDim(300), zDim(400);
>
> should it be like int(300) or float(300), some thing lie that
>
> Jothy
>
>
> On Wed, Aug 24, 2011 at 3:51 PM, Pierre-Andre Noel <
> noel.pierre.andre_at_[hidden]> wrote:
>
>> >> I am not familiar with multi_array, but it seems that you are creating
>> a >1GB object on the stack. This will almost always crash. Try creating it
>> on the heap instead. Be prepared for std::bad_alloc.
>>
>> > But how to do this? I am new to c++.
>>
>> I suggest you to either 1. read on the operators "new" and "delete" or 2.
>> use a std::vector to allocate the memory then use a boost::multi_array_ref
>> to refer to it. Here's an example:
>>
>> #include <vector>
>> #include <boost/multi_array.hpp>
>>
>> int main()
>> {
>>   typedef float data_type;
>>   typedef std::vector<data_type> array_storage_type;
>>   typedef boost::multi_array_ref<data_type,3> array_ref_type;
>>
>>   array_ref_type::size_type xDim(500), yDim(300), zDim(400);
>>   array_storage_type Storage(xDim*yDim*zDim);
>>   array_ref_type Array(&Storage.front(),boost::extents[xDim][yDim][zDim]);
>>   // You may now use Array as usual.
>> }
>>
>> Hope it helps,
>>
>> Pierre-André Noël
>>
>>
>> On Wed, Aug 24, 2011 at 5:20 AM, Jothy <jothybasu_at_[hidden]> wrote:
>>
>>> Thanks for pointing this out.
>>>
>>> But how to do this? I am new to c++.
>>>
>>> Jothy
>>>
>>>
>>> On Tue, Aug 23, 2011 at 10:42 PM, Juraj Ivančić <juraj.ivancic_at_[hidden]
>>> > wrote:
>>>
>>>> On 23.8.2011. 12:18, Jothy wrote:
>>>>
>>>>> Hi all,
>>>>>
>>>>> I have just started to use boost libs. I am trying to create a large
>>>>> float array (mandatory for my purpose). it works fine till certain
>>>>> limit, but crashes above that. I think it about allocating memory in
>>>>> the
>>>>> stack.
>>>>>
>>>>> My code is like this
>>>>>
>>>>> typedefboost::multi_array<**float,3>array_type;
>>>>> typedefarray_type::indexindex;
>>>>> array_typeArray(boost::**extents[xDim][yDim][zDim]);//**500,300,400
>>>>> for instance
>>>>>
>>>>>
>>>>> Can some one help me to resolve this?
>>>>>
>>>>
>>>> I am not familiar with multi_array, but it seems that you are creating a
>>>> >1GB object on the stack. This will almost always crash. Try creating it on
>>>> the heap instead. Be prepared for std::bad_alloc.
>>>>
>>>> HTH
>>>>
>>>>
>>>> ______________________________**_________________
>>>> Boost-users mailing list
>>>> Boost-users_at_[hidden]
>>>> http://lists.boost.org/**mailman/listinfo.cgi/boost-**users
>

>>>>
>>>
>>>
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>>
>>
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>
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