----- Original Message -----
Sent: Friday, January 05, 2001 5:16
PM
Subject: MI-L Combining Similar Polygons
selectively.
Hello again, all....
My
problem has yet to be solved, to I will present it to you again with some of
the background replies. Let me update my previous stats. I have 23
different fields in my table. The map is broken down to reflect at least
10 of these fields. I would like to be able to combine all polygons that
have all 10 of those fields in common. However, if only 9 are matching,
but 1 is different, I don't want those polygons combined. The problem
with using the "Combine Objects Using Column" command is that it only looks at
one field and ignores the other 9 and in the process I lose the rest of my
map. Is there a program/process by which I could combine all the
polygons where all 10 of those fields (or any number of my choosing) match,
but not combine the polygons where at least 1 of those fields do not
match? Thank you all for your help.
-Evan ([EMAIL PROTECTED])
<begin quote 'reply string'>
Ok,
That works if the only thing I have as part of
each county are the flood zones and maps. Unfortunately, the counties
also have the cities boundaries showing as well. How can can get rid of
the old map lines, while keeping the new maps lines AND the city
boundaries? It is not easy to re-create the city boundaries because many
of them are extremely complex. My table has 23 different fields in
it. 21 of them have set values that are different from polygon to
polygon. Is there a way I can combine only the polygons that have all 21
of those neccessary fields matching? Not just combining using 1 field,
but all of them at the same time? I don't want to combine different
cities into one, i want them to stay separate. Any process/program for
doing that?
-Evan
([EMAIL PROTECTED])
-----Original Message-----
From: Will Mitchell [SMTP:[EMAIL PROTECTED]]
Sent: Wednesday, January 03, 2001 12:23 PM
To: Macdougall, Evan 1065;
[EMAIL PROTECTED]
Subject: RE: MI-L Combining matching
polygons
Hi Evan,
From your description it sounds like you can
use the TABLE Menu Command > "Combine Objects Using Column".
This
will create the merged polygons that you need either as new objects in your
same table or into a new table. I find it easier to just let them be
added to the existing table, then you can save them out as a new file and
revert the base table...this way you don't have to set up a blank table with a
matching field structure ahead of time to dump into.
Good
luck.
Will Mitchell
Mitchell Geographics, Inc.
496 Congress
Street
Portland, ME 04101
www.mitchellgeo.com
ph 207.879.7769
fx
207.253.5756
-----Original Message-----
From:
[EMAIL PROTECTED] [ <mailto:[EMAIL PROTECTED]>]On Behalf Of Macdougall, Evan 1065
Sent: Wednesday, January 03, 2001
2:55 PM
To: '[EMAIL PROTECTED]'
Subject: MI-L
Combining matching polygons
Hello
all,
I have a perplexing problem that maybe there
is a solution to. If you can help me, let me know.
Here's
my problem: I am working with FEMA flood maps for various counties for
the U.S. Each county is broken down into a variable number of
different maps, each showing 3, 4 or more different flood zones.
However, sometimes, the maps change shapes and sizes. So, say a county
that once was broken up into a 4x4 grid is revised by FEMA and is now broken
up into a 7x7 grid. I can use gridmaker to make grids to match the net
map designs, that is not a problem. However, the old map boundaries
are still there and i now have side-by-side polygons with the same
information sitting next to each other, all over the map. Is there
there a program/process that will compress the graphical data by combining
adjacent polygons which have matching data? So, is there a way that I
can remove the old map boundaries after cutting in the new ones without
having to go map-by-map, polygon-by-polygon to combine the ones with
matching info myself? Any help would be very much appreciated
(very very much).
-Evan
([EMAIL PROTECTED])
<end quote 'reply string'>
