Dear List

Thanks to all those who replied.  Simon O'Keefe suggested that I should work
on the hard vegetation and then the soft vegetation, which would mean using
two queries (much reducing the burden of doing individual queries on 108
sets of data).  I then decided to adapt an old SQL command that I had in
stock (originally from MI Technical Support) and it worked a treat.  I
checked its accuracy using the cookie-cutter on one of the soft intertidal
substrates and the results were exactly the same.  The command is as
follows:

(Bird Count Zone = Table name, BCZone ID = field; Intertidal Hard Vege =
Table name, Vege Type = field)

Select columns: Bird Count Zone. BC_zone_ID, Intertidal Hard Vege. Vege Type
, sum ( proportionoverlap (Bird Count Zone. obj , Intertidal Hard Vege.
obj ) * area ( obj , "hectare" ) )

>From Tables: Bird Count Zone, Intertidal Hard Vege

Where condition: Bird Count Zone . Obj intersects Intertidal Hard Vege . Obj

Group by: Bird Count Zone. BCZone ID

Order by columns: Bird Count Zone. BCZone ID

Into Table Named: selection

Cheers!

Jacqui Foskett




_______________________________________________________________________
List hosting provided by Directions Magazine | www.directionsmag.com |
To unsubscribe, send e-mail to [EMAIL PROTECTED] and
put "unsubscribe MapInfo-L" in the message body.

Reply via email to