Re: [boost] Is anyone interested in dynamic multi array libarray

From: garcia (garcia_at_[hidden])
Date: 2004-02-10 23:00:34

Greetings,

I am trying to grok what it is you describe, but I am afraid I may be 
missing something.  Could you explain in what ways dynamic_multi_array 
differs from the arrays in the Boost.MultiArray library? 

Thanks,

ron

RGProlog_at_[hidden] wrote:

> Is anyone interested in dynamic_multi_array template library that 
> offers user intuitive convenience of use as well as capacity to hone 
> in upon any specific subset of a multi-dimensional array?  As an 
> example of usage, a dynamic_multi_array object can be constructed and 
> then resized and then reshaped like this:
>
>    size_t arrayShape = { 3, 7,  15};
>
>    dynamic_multi_array<double, 3>  A(arrayShape);
>
>    boost::array<size_t,  3>  anotherArrayShape = {{ 5, 4, 22}};
>
>   A.resize(anotherArrayShape);
>
>    boost::array<size_t,  5>  yetAnotherArrayShape =  {{ 440, 1, 1, 0, 
> 0}} ;
>
>   A.reshape(yetAnotherArrayShape);
>
>    size_t stillAnotherArrayShape[4]  = { 22, 10, 2, 11};
>
>   A.reshape(stillAnotherArrayShape);
>
> The library’s design owes a lot to Andrei Alexandrescu’s ideas. It is 
> based on the data_table helper class template defined as follows:
>
> template<typename X>
>
> class data_table {
>
> …
>
> protected:
>
>     std::vector<X>  data_table_ ;};
>
> template<> <value_type>
>
> class data_table {
>
> …
>
> protected:
>
>     value_type* data_table_ ;};
>
> Then, a sequence of the table class instantiation types is recursively 
> defined and then given a name that is shared in different dimensional 
> contexts as follows:
>
>  
>
> typedef  data_table<value_type>  data_table_01;
>
> …………………………………………….
>
> typedef  data_table< data_table_49 > data_table_50 ;
>
>  
>
> class Int2Type<int> {
>
>     typedef data_table_01 data_table;
>
> }
>
> ……………………………………………
>
> class Int2Type<> <50> {
>
>     typedef data_table_50 data_table;
>
> }
>
> Being a recursive template class, the data_table is implemented in a 
> concise code that is mostly about stating a few recursive rules and 
> implementing some access operators and is totally dimension 
> independent.  This is the central feature of the design since the user 
> level wrapper class template by virtue of exporting a dimension 
> appropriate data_table instantiation that uses its shared name
>
> template <T, size_t i, Allocator>
>
> class dynamic_multi_array {
>
> ……………………………………….
>
> typedef  …. class Int2Type <i>::data_table;
>
> }
>
> is also implemented in a way that hides all the implementation 
> details, is concise and  dimension independent, thus providing user 
> with a great deal of flexibility, syntax safety, and,  in case of a 
> new user, a flat learning curve.  This is a std::vector based design. 
> The dynamic_multi_array template class, the library’s main component, 
> extends, where appropriate, std::vector capacities, replicates its 
> exception safety guarantees and has std::vector as its back end 
> storage device.
>
>    The library’s code, documentation including a short tutorial and a 
> few key tests and will be posted in Dynamic Multi Array Folder on 
> boost Files once the issue of available space will be resolved.
>
>  
>
>  
>
>------------------------------------------------------------------------
>
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