Thanks to Eric, Mikhail and Jason for their suggestions.
Suggestions included:
- creating a unique ID for each table based upon centriodX
and centroidY and linking based on the result.
- linking based on rowid (be careful, does not always work!!!).
- using an SQL query to select points, calculate distances, group
results and select the first point in each resulting group.
Eric's suggestion steals the show for speed and simplicity:
Save a copy of your point table with columns for the lat
and long coordinates and type the following into the MapBasic
window ("yourtable" will be your table name, "xcoord" and
"ycoord" are whatever you called your lat and long fields and
"radius" is your desired buffer radius. Be sure to remember
to set your distance units properly):
update yourtable set obj = createcircle(xcoord, ycoord, radius)
The result is a table of circular buffers where each buffer retains
all the attribute data from its source point - exactly what I was
looking for! Ain't this list great?!!
Rob Batenburg
Pacific Agri-Food Research Centre
Agassiz, British Columbia, Canada.
[EMAIL PROTECTED]
>>> "Rob Batenburg <[EMAIL PROTECTED]> 03/15 11:10 am >>>
> I have a table containing trap locations (traps) and a table of
> 200 metre buffers (buffs), one for each point in the traps table.
> I would like to assign each buffer an ID that is equivalent to
> the ID of the trap from which it was created. Unfortunately,
> the critters to be trapped are plentiful and the number of traps
> is substantial. The buffers overlap and each buffer contains0
> more than one trap, thus a simple "buffer contains trap" join
> will not work ... <snip> ... Is there a way to force MI to transfer
> attributes of the source table (traps) to the output table (buffs)
> when calculating buffers?
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