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Re: st: New version of -spmap- available from SSC


From   Maurizio Pisati <maurizio.pisati@unimib.it>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: New version of -spmap- available from SSC
Date   Sat, 15 Mar 2008 07:35:15 +0100

Dear Volodymyr,
computing power apart, the speed basically depends on the number and complexity of spatial objects you ask -spmap- to draw. In your specific case, drawing 670 polygons is a relatively time-consuming task, especially if each polygon is represented in a very detailed manner, i.e., is made up of a lot of nodes. In such cases, speed can be substantially increased if you use a "simplified" version of your map, namely one in which the constituent polygons are - so to speak - "smoothed" (for instance, by applying the Douglas-Peucker line simplification algorithm or one of its variants).
Best,
Maurizio



Reference
Douglas, D.H. and T.K. Peucker. 1973. "Algorithms for the reduction of the number of points-required to represent a line or its caricature", The Canadian
Cartographer 10: 112122.





At 01.07 15/03/2008, you wrote:

Thank you for a great program!

I have used it since last Summer to map 670 regions in Ukraine. It was
my impression that it works a bit slow. What does the speed depend on?

Volodymyr.


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