Basic Question for the "Expression Builder"

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  • Start date Start date
G

Guest

I have two tables loaded into a "Select Query". One table contains
coordinates for a "subject", the other table contains coordinates for many
"sites". i have an expression that returns the distance of each of the
"sites" from the "subject". Now i have a "subject" which happens to be a
polygon and contains multiple coordinates for each point in the polygon.
This has rendered my expression useless.

I would like to use my expression to retrieve the distance of each "subject"
coord from each "sites" coord.

Here is what i used when "subject" had one set of coordinates:

Expr1:
((([subject.x]-[sites.x])*69.09332)^2+(([subject.y]-[sites.y)*69.09332)^2)^0.5

I have no idea how to express that i would like to calculate the distance of
row 1 of "subject" coords from row 1 of "sites" coords, then move to row 2 of
"subject" coords calculate distance from row 1 of "sites" coords and repeat
until it reaches the end of "subject". Then start again comparing row 1 of
"subject" coords with row 2 of "sites" coords, and row 2 of "subject" coords
with row 2 of "sites coordinates, and so on.

Any Help or suggestion is so appreciated.
Thanks in advance
 
If there is no relation between the Subject table and the Site table,
then when you add a coordinate field from Subject and a coordinate field
from Site, your query should have a row for every combination like you want.
Then your expression would be computed for every combination? If you simply
want the results sorted by Subject coordinate that should be
straightforward?

Doug M
 
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