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authorBruce Momjian <bruce@momjian.us>2004-06-02 21:34:49 +0000
committerBruce Momjian <bruce@momjian.us>2004-06-02 21:34:49 +0000
commit70f5a87ecc4cfa8810fb27ad55fa4904dcb40a6a (patch)
tree67d62e575b05ccedf5fffff9aed8a4b4007335e3 /src/bin/scripts/createlang.c
parente8d9d68ca4866c775b5d1170581ac9e1ade3abd8 (diff)
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Small patch that adds some documentation for the area() function.
Specifically, point out that intersecting points in a path will yield (most likely), unexpected results. Visually these are identical paths, but mathematically they're not the same. Ex: area | plan ------ +----------------------------------------------------------------------- ------------------- -0 | ((0,0),(0,1),(2,1),(2,2),(1,2),(1,0),(0,0)) 2 | ((0,0),(0,1),(1,1),(1,2),(2,2),(2,1),(1,1),(1,0),(0,0)) The current algorithm for area(PATH) is very quick, but only handles non-intersecting paths. I'm going to work on two other functions for the PATH data type that determines if a PATH is intersecting or not, and a function that returns the area() for an intersecting PATH. The intersecting area() function will be considerably slower (I think it's going to be O(n!) or worse instead of the current O(n), but that comes with the territory). Sean Chittenden
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