Re: SparseArray, DensityGraphics, ContourGraphics, and SurfaceGraphics

*To*: mathgroup at smc.vnet.net*Subject*: [mg54706] Re: SparseArray, DensityGraphics, ContourGraphics, and SurfaceGraphics*From*: Jon Harrop <usenet at jdh30.plus.com>*Date*: Sun, 27 Feb 2005 01:29:54 -0500 (EST)*References*: <cvc84d$qrb$1@smc.vnet.net> <cvk485$dat$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Jens-Peer Kuska wrote: > what has a sparse matrix to do with a density graphics ? RLE. > ArrayPlot[] is only used to visualize the sparse matrix, but > all the memory saving of the sparse matrix are destroyed when you > expand every entry in the matrix (not only the non zero values) to a > 3D Polygon[] with 4 corners in Plot3D[] ... Only if you tesselate uniformly. If you adaptively subdivide then you can retain sparseness. > It seems a good design decision not to support this nonsens ... The OPs question is perfectly valid. The answer, I suspect, is simply that WRI have not yet implemented it. Although not insurmountable, this is not a trivial problem to solve properly. -- Dr Jon D Harrop, Flying Frog Consultancy http://ffconsultancy.com