RE: [Maptitude] Distance to the 1st and 2nd nearest road

[Hoskins, Richard E. \(DOH\)]

this makes sense - thanks for your getting me started ... !   D From: Maptitude@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Peter H. Van Demark Sent: Wednesday, June 28, 2006 11:46 AM To: Maptitude@yahoogroups.com Subject: Re: [Maptitude] Distance to the 1st and 2nd nearest road Richard: >One can use the tag feature to get the distance to the nearest road from a >point, but is there a way to get the distance to the 2nd nearest road? There are two similar GISDK functions: - LocateNearestRecord() finds the map feature that is nearest a point location and returns its record handle. - LocateNearestRecords() finds the map features, within a search distance and sorted by increasing distance, that are nearest a point location and returns their record handles. So, you could use the second function and: - The new ArrayElementToString() or A2S() function to pick off the second record handle and use it to get - The line ID with the RecordHandleToID() or RH2ID() function, then get - The coordinates in the line with the GetLine() function, and then get - The distance from the point location to the line with the GetLineDistance() function You will need to do this with a GISDK macro, because LocateNearestRecords() locates records in the working layer (the line layer), and you want to put the distance into a field in the point layer. If pnt_loc is the coordinate for the point location and search_dist is the search distance, this should give you the distance to the second-nearest line: arr = GetLineDistance(pnt_loc, GetLine(RH2ID(A2S(LocateNearestRecords(pnt_loc, search_dist, ), 2)))) The first element of arr is the distance. Your hoemwork is to add the management of looping over the points, switching the working layer to the line layer to get the distance, and switching back to write the distance into the point record. Peter ---------------------------------------------------------- Peter H. Van Demark Director of GIS Products and Training Phone: 617-527-4700 Caliper Corporation Fax: 617-527-5113 1172 Beacon Street E-mail: [EMAIL PROTECTED]com Newton MA 02461-9926 Web site: http://www.caliper.com __._,_.___ SPONSORED LINKS Geographic information systems Geography game Geography YAHOO! GROUPS LINKS  Visit your group "Maptitude" on the web.    To unsubscribe from this group, send an email to:  [EMAIL PROTECTED]    Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. __,_._,___