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visits member for 3 years, 4 months
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asked Unable to connect to PostGIS databases after Mac OS X Yosemite upgrade
Jul
14
comment Low quality legend symbols in QGIS
Issue seems to be fixed after updating to QGIS v2.4.0.
Jun
30
asked Low quality legend symbols in QGIS
May
8
accepted remove duplicate points based on a specified distance
May
7
revised remove duplicate points based on a specified distance
code update
May
7
revised remove duplicate points based on a specified distance
updated code
May
7
comment remove duplicate points based on a specified distance
@Andy W - the dates are date types, not timestamp types, so orderring by date gives me duplicate events that happened on the same day. i did realize a deficiency in my solution though: if i have 4 points all on the same date, with one pair close together, the other pair close together, but the two pairs are far apart, my query would consider those all duplicates and only select 1 event rather than 2. adding a field with the pair centroid and using that in the distinct on clause would work (code above updated). my solution also only works when there are at most 2 potential sources.
May
6
awarded  Self-Learner
May
5
awarded  Teacher
May
5
answered remove duplicate points based on a specified distance
May
5
revised remove duplicate points based on a specified distance
update about query
May
5
awarded  Student
May
5
comment How to smooth the polygons in a contour map
i've used the v.generalize function in GRASS to do smoothing of contour lines with decent results, although it can take awhile for maps with very dense contours.
May
5
comment How to smooth the polygons in a contour map
how are you generating 'polygon' contours? wouldn't they always be lines, since a contour intersecting the edge of a DEM would never close upon itself?
May
5
awarded  Editor
May
5
revised remove duplicate points based on a specified distance
added possible solution
May
5
comment remove duplicate points based on a specified distance
@whuber - yes, it's not clear what should be considered duplicates in the situation you proposed. i think such a case would be rare in my dataset. actual duplicates tend to be 10s to 100s of meters apart, while truly different points on the same date are likely 1000s of meters apart. thanks for the link to the other solution. i think the st_snapToGrid function might do what i need (query added to question above).
May
4
asked remove duplicate points based on a specified distance
Mar
29
awarded  Scholar
Mar
29
accepted Arcpad Message Box and Keyboard Button Issue