Listers, I got a couple of responses to my post a while ago and Russells was 'fit-for-purpose', spot on. Thanks Russell, sorry about the tardy reply, this one got away from me!
Rgds, Dave -----Original Message----- From: Lawley, Russell S [mailto:[EMAIL PROTECTED] Sent: 12 June 2003 12:31 To: 'Eagle, David A' Subject: RE: MI-L Overlapping Polylines David the following should work...(not tested on your data but works on similar stuff i am doing) if your table DOESNT already have a unique id for each object add an integer column to the table called roadID and update it with the keyword 'rowid' to get a unique value) . now make a copy of the table call it tableB and open it now run the following query Select roadtab.roadID, sum ( ObjectLen ( intersectnodes ( tableB.obj, roadtab. obj , 7 ) , "m" ) ) from roadtab, tableB where roadtab.obj intersects tableB. obj and roadtab.roadID <> tableB.RoadID group by roadtab.roadid into allroadsoverlapvals now run the following Select * from roadtab where not roadID in ( select col1 from allroadsoverlapvals where col2 > 0 ) into roadswithoverlaps map the result et voila! if you want to make a table just showing the overlap objects then you need a little MBX to trawl thru thetable creating tehmap object for each overlap hth R -----Original Message----- From: Eagle, David A [mailto:[EMAIL PROTECTED] Sent: Thursday, June 12, 2003 12:02 PM To: MapInfo-L ([EMAIL PROTECTED]) Cc: Hall, Barry E Subject: MI-L Overlapping Polylines Listers, I have a layer of polylines representing a road network. At a junction/intersection a new polyline starts from the end point of the last. However, in a very small number of cases some of the links have sections that overlap i.e. Polyline 1 (3 nodes, 2 sections) and Polyline 2 (3 nodes, 2 sections) exist but Polyline 2 has node 1 on node 2 of polyline 1 and node 2 on node 3 of polyline 1, such that link 2 of polyline 1 and link 1 of polyline 2 overlap. Do you follow? ;o) I need to highlight all of these anomalies can anyone help or offer up a tool to automate this I can't seem to find one that does the job? Much appreciated! Rgds, Dave ---------------------------------------------- David A. Eagle GIS Consultant Atkins Design Environment & Engineering Cornerstone House Stafford Park 13, Telford Shropshire, TF3 3AZ England Tel: +44 (0)1952 21 3268 * Fax: +44 (0)1952 20 0981 * Email: [EMAIL PROTECTED] * Web: www.atkinsglobal.com <www.atkinsglobal.com> * 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: 7247 ********************************************************************* This e-mail message, and any files transmitted with it, are confidential and intended solely for the use of the addressee. If this message was not addressed to you, you have received it in error and any copying, distribution or other use of any part of it is strictly prohibited. Any views or opinions presented are solely those of the sender and do not necessarily represent those of the British Geological Survey. The security of e-mail communication cannot be guaranteed and the BGS accepts no liability for claims arising as a result of the use of this medium to transmit from or to the BGS. The BGS cannot accept any responsibility for viruses, so please scan all attachments. http://www.bgs.ac.uk ********************************************************************* 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: 7619
