Is this the Oracle defn also? I had always interpreted DWithin to
mean "within distance of", so that
DWIthin(A,B,100) was functionally equivalent to Distance(A,B) < 100
P
On 27-May-07, at 2:23 PM, Kralidis,Tom [Burlington] wrote:
Further info from Peter Vretanos (FES 1.0.0 spec editor):
"According to the BNF in the Cat 1.0 specification DWithin tests to
see
whether geometry A is completely within a certain distance of geometry
B.
I interpret this to mean a "buffer" query. That is you create a
buffer
around A at the specified distance and then do a WITHIN (as defined in
SFSQL) between this new buffer-expanded geometry (A') and the test
geometry B. If B is completely within A' then the operator
evaluates to
true
BEYOND is the opposite of DWITHIN. If B is completely outside of A'
then the operator evaluates to true."
Cheers
..Tom
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