On 05/28/2016 07:12 AM, Kouhei Kaigai wrote:
> Sparse matrix! It is a disadvantaged area for the current array format.
>
> I have two ideas. HPC folks often split a large matrix into multiple
> grid. A grid is typically up to 1024x1024 matrix, for example.
> If a grid is consists of all zero elements, it is obvious we don't need
> to have individual elements on the grid.
> One other idea is compression. If most of matrix is zero, it is an ideal
> data for compression, and it is easy to reconstruct only when calculation.
>
>> Related to this, Tom has mentioned in the past that perhaps we should
>> support abstract use of the [] construct. Currently point finds a way to
>> make use of [], but I think that's actually coded into the grammar.
>>
> Yep, if we consider 2D-array is matrix, no special enhancement is needed
> to use []. However, I'm inclined to have own data structure for matrix
> to present the sparse matrix.
+1 I'm sure this would be useful for PL/R as well.
Joe
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