David, One thing is that the MAP file also contains the spatial index, and so not only the number of nodes in your polygons, but also their location is relevant when looking at the size of the MAP file. Maybe MapInfo optimizes the spatial index when you pack the table/save copy as etc. and when optimizing the index it m ight get bigger on the disk, but hopefully this will also result in a faster access to the objects in the table.
Just my idea, Peter Horsb�ll M�ller GIS Developer Geographical Information & IT COWI A/S Odensevej 95 DK-5260 Odense S. Denmark Tel +45 6311 4900 Direct +45 6311 4908 Mob +45 5156 1045 Fax +45 6311 4949 E-mail [EMAIL PROTECTED] http://www.cowi.dk/gis -----Original Message----- From: Eagle, David A [mailto:[EMAIL PROTECTED] Sent: Wednesday, April 06, 2005 6:33 PM To: [email protected] Subject: MI-L Line generalisation All, There are some strange goings on inside my computer that I find hard to understand...can anyone help. In the course of my daily grind I have found it necessary to generalise a dataset of polylines that represents a road network. This particular dataset is quite heavy and at the scale I am printing it the detail is not important. So I am using the Object > Snap/Thin tool in MapInfo to thin down the number of nodes in the network. That done my network is generalised, so I save the table, pack it, close it and have a look at the file size in explorer.... ...would you believe that despite removing detail from the MAP file by generalising the network the *.map file is marginally bigger than the original?! Can anyone explain this one for me, it seems a little backward? I have tried this with several different networks of differing detail and geographical spread with the same result. Also, in the process of this task I have noticed that using the 'Save copy as' feature also creates a set of files where the *.map file is bigger than the original...despite it being a COPY? If someone could shed some light on these weird occurrences, my Wednesday afternoon would not have been in vain! Many thanks, Dave This email and any attached files are confidential and copyright protected. If you are not the addressee, any dissemination of this communication is strictly prohibited. Unless otherwise expressly agreed in writing, nothing stated in this communication shall be legally binding. --------------------------------------------------------------------- List hosting provided by Directions Magazine | www.directionsmag.com | To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] Message number: 15969
