Greetings All: Do SHP files contain projection information, and especially, can they contain a "bounds clause"??
I think I've found a problem in the way the Universal Translator handles a special projection that applies only to the state of Michigan. Below is MapInfo TechSupport's 1st response (canned I think). Per their suggestions: I checked the KnowledgeBase and it doesn't contain anything pertinent. And, per their suggestion, I'm posting all this on MapInfo-L for whatever words of wisdom you all may have. I'm also responding with our Serial # as they requested. My message to TechSupport explaining the problem is below their canned response. I can send the 2 files that were attached to the original message to anyone wanting to play with this problem. Any help would be appreciated. .....thanks .....Bob >>> <[EMAIL PROTECTED]> 2/12/03 5:51:00 PM >>> Robert, Please include your registered product serial number so we can assist you further.Otherwise, you can access our full knowledgebase on all the MapInfo Products at: http://testdrive.mapinfo.com/kbase_by_product.You can also post your question to the MapInfo-L discussion area.This discussion area is not moderated by MapInfo employees and is a user/community based discussion area. More information on this discussion area can be obtained at the MapInfo Test Drive Center: http://mapinfo.com/support/technical_support/lists.cfm. Dave S. MapInfo Technical Support (518) 285-7283 [EMAIL PROTECTED] MapInfo Products Knowledgebase: http://testdrive.mapinfo.com/kbase_by_product "Robert Karr" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Subject: Universal Translator & Michigan Geo Ref projection 02/12/2003 04:22 PM Greetings: I'm beginning to believe, but not sure, that the Universal Translator is not functioning correctly for a projection that is specific to just the state of Michigan. The parameters for the MichGeoRef projection are: ***************** "Michigan GeoRef", 7, 74, 7, -86, 45.3091666666, 337.25556, .99960, 2546731.496, -4354009.816 ***************** With these parameters entered in the MapInfoW.prj file, we can translate a SHP file supposedly successfully but find the western part of the state is "truncated", actually, compressed into a vertical line. The rest of the displayed map data seems to be exactly where it should be and fits very nicely with other layers Using a MBX called "CoordSys Bounds Manager (Version 1.4)", we can see the Table CoordSys Name and Clause as extracted from the .TAB file. The CoordSys name, "Michigan GeoRef (1983, meters)\", can be seen as expected, but the Clause parameters , "CoordSys Earth Projection , 7, 33, "m", -86, 45.3091666666, 337.25556, .99960, 2546731.496, -4354009.816 B.......", are slightly different., and I can see what I think is the start of Bounds statement but the window is too short to display all of it. The "33" datum is the "Geodetic Reference System" based on ellipsoid GRS 80. I'm guessing it is some sort of "generic" worldwide datum. Certainly not the same as the NAD83 that should be there in the form of a "74", even though both are on based on GRS80. I'm not sure the "m" used is significantly any different than the "7" used to specify the units. The MBX also has a function that draws the outline of the bounds of TAB files. When used with the resulting TAB file translated from the SHP file that is attached, a rectangle something like a UTM zone is drawn roughly pole to pole, 13,500 miles wide, and cuts through the western part of Michigan exactly where the displayed map data ends. The more I play with this, the more I'm convinced the problem is the Universal Translator itself, not the parameters we're feeding it. The change of datum may be part of the problem, but probably not. I think the only problem that might create has to do with fineness of resolution being worldwide instead of regional. I'd like to see what the rest of that Bounds statement says, but I don't know how to view the coordsys info in a TAB file other than to use the CoordSys Bounds Manager MBX. I'm beginning to think the Universal Translator is adding a bounds clause that is causing the "truncating". I added a bounds statement to the MichGeoRef entry in my .PRJ file: "--- Michigan GeoRef Coordinate Systems (1983, meters) ---" "Michigan GeoRef (1983, meters)\", 2007, 74, 7, -86, 45.3091666666, 337.25556, 0.99960, 2546731.496, -4354009.816, 0, 0, 1000000, 1000000 Attached are 2 files: One is .TAB file of Michigan Counties in Michigan State Plane NAD27; the other is a SHP file of community college service areas in Michigan drawn in MichGeoRef. I can copy the county map, save it as MichGeoRef and display it correctly without problem, but translating the SHP file produces the "truncating" effect. So far, it seems when trying to translate any SHP file with map data in that part of the state created in MichGeoRef produces the same result. Can you give us some help clarifying what's happening, and/or fix it?? ....thanks ....Bob Robert Karr Phone: 517-373-3028 GIS Operator FAX: 517-373-0171 Science and Technology Division Legislative Service Bureau Michigan State Legislature 124 West Allegan Street, 4th Floor pob 30036 Lansing, MI 48909-7536 USA --------------------------------------------------------------------- List hosting provided by Directions Magazine | www.directionsmag.com | To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] Message number: 5512
