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 -- Crunchy Data - http://crunchydata.com PostgreSQL Support for Secure Enterprises Consulting, Training, & Open Source Development
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