Maptitude - http://research.umbc.edu/~roswell/maptitude.html I may have mislead Kevin in my understanding of how hi-res county boundaries lead to interior holes and bisected counties. I think the problem arises not because water blocks need to be removed, but because they aren't there to begin with. The hi res layer has holes without attributes. You can check this by opening the county hi-res file (it opens centered in Kansas) and check out the lake area in Russell county with the "Info" tool. It's empty, but the remainder of Russell County has appropriate data descriptors. Perhaps the answer is to have a medium resolution county file like we have for states. I'm not even sure how a utility would work conceptually with the given data structure underlying the map. Some other observations on the issue. 1. We always have access to the water blocks layer if we need to show major water bodies in a map, so we can "cover up" the holes for some displays. 2. Sometimes we need a "strong" display of county (or MCD) boundary, but then we get an irregular coverage when trying to hide the holes, as in #1. 3. Sometimes using invisible county boundary lines with filled county areas showing different county outlines by using thematic display (manually setting colors for non-obtrusiveness) can still show county areas but this is limited to just a few counties or MCDs because of the manual labor involved. 4. Sometimes we want to show some water areas but not others, usually showing shoreline areas but not interior lakes and rivers. It's difficult to see how a utility feature could solve this since the underlying census geography doesn't make the distinction in water block coding. 5. When I've just really needed to make the map look right, I've been forced to a deadfully time consuming manual recode of blocks (after running ImportTiger including all water blocks)where I've created pseudo-counties at the shoreline (like along New York's Lake Ontario area), but that gets very difficult for other areas when you start looking at offshore islands, barrier islands, etc. and it isn't worth the time unless it's an important client paying for a major project. David Buckley >From: kbyrnes <[EMAIL PROTECTED]> >Reply-To: Maptitude <[EMAIL PROTECTED]> >To: Maptitude <[EMAIL PROTECTED]> >Subject: [Maptitude] Maptitude Enhancement Request >Date: Mon, 04 Dec 2000 20:19:08 -0500 > >Maptitude - http://research.umbc.edu/~roswell/maptitude.html > >I appreciate David's explanation of the source of the problem of water >blocks. The high >resolution polygon files distributed by Caliper include water blocks (which >include >rivers). When building extracted polygon geographies from the national >data files, it is >frustrating to get counties (or other areas) bisected by rivers and >pock-marked by all >the internal water blocks which may exist. It would be extremely helpful >if Caliper >introduced a utility routine which could expedite merging these features >(e.g. by a >modified polygon overlay process which would, in effect, erase all internal >water block >features) so that area polygons selected and exported to unique files are >whole and >intact. I've used the tedious manual map editing procedures and have had >problems with >system crashes when trying to "remove" internal water blocks. >Kevin Byrnes >Va. Dept. for the Aging > >David Buckley wrote: > > > Maptitude - http://research.umbc.edu/~roswell/maptitude.html > > > > I agree. Great Mapplication! Same with MassStat. > > > > It does, however, lead me to a "wish list" item which I have discussed >with > > Caliper tech staff but thought I'd air here for a list response. > > > > The way hi res county maps appear, with the county outlines distorted by > > larger bodies of water and their outlines, sometimes even interior lakes > > with "holes", really looks distracting. It's real obvious with the > > national election map at smaller area views, and the MassStat site seems >to > > have the same problem with MCDs. > > > > I know why it happens: the Import Tiger function and the choices of > > importing with and without water blocks, avoidable only by GISDK >scripting > > (to keep all the water blocks) using raw Tiger files. For me that ends >up > > only being a minor irritation because I use lots of Tiger block file >maps, > > but for regular users (or those not using DK) it can be a real pain. > > Thematic maps really get chunky with big holes and counties get >arbitrarily > > separated if dissected by a water body -- and that confuses the county > > border identification. > > > > I also am aware of the alternative by including (by default) water >blocks. > > States like New York have county boundaries that extend into >surrouonding > > water bodies like Lakes Erie and Ontario, and Long Island Sound and the > > Atlantic, equally distorting the common sense "image" of the state and >its > > counties. > > > > Isn't there any alternative? > > > > David Buckley > > >_____________________________________________________________________________________ > > Get more from the Web. 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