I don't program, but I have dealt with this need before, the difference was
that it was zoning districts, not neighborhoods, but its the same problem.
What I ended up doing was creating a thematic map so I could see all the
zones, then drew the regions down the center of the streets.  If you check
the voids where streets are, are they all precise, consistent? probably not,
making a routine even harder to write.  Making one region programmatically
is compounded by making sure adjacent regions are topologically correct.
Depending on the number of neighborhoods, it would probably be done faster
freehand then programmatically.  I found that as I built more regions the
work became faster, as I started to snap to adjacent regions, minimizing
zooming in and out.  I "freehanded" down the street centers, and only
spotted a node when the street changed directions enough to warrant it.
Another Idea that occurred to me is to use a street centerline table, select
segments that form the neighborhoods, copy/paste to another table, combine
and change to regions, but if the street segments don't end at
intersections, adjusting the street polylines would be more work than its
work, I suspect.

William "Woody" Woodruff
Zoning Administrator
Charter Township of Union, Isabella County, Michigan
2010 S Lincoln Rd, Mt. Pleasant, MI  48858
(989) 772 4600 EXT 41
Visit our web site at http://www.geocities.com/ctuzoning/index.htm


-----Original Message-----
From: Juanse [mailto:[EMAIL PROTECTED]]
Sent: Saturday, January 25, 2003 9:05 AM
To: MapInfo
Subject: MI-L block to neighbourhood


Hi everyone

I am working for this municipal client and need to combine street blocks
(polygons) to form the neighbourhood polygon but with the aditional trick
that the "empty spaces" between the block (equivalent to the street public
land) desapear so as to form a continuos polygons �does it sound coherent?.

If I do the "object/set target/combine" operation offer by mapinfo I end up
with one polygon that is formed by the block polygons with nothing in the
empty space between the block.

Any ideas on how to do this as automatically as possible?. Yes I do have a
field in the block table that stores the neighborhood attribute for
performing the select.

[] []
[] []
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|__|

Juanse
temuko-Chile



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