Hi, Matthias Scholz wrote:
> Hi Uwe, > yes there is a small trick, if we talk about the same problem. > 1) go to Customize -> Options -> Snap/Grid -> Snap to vertices and select the > right snapping tolerance for your needs. > 2) draw the draw the linestring > 3) through the snap funktion you can easy draw the last point on the first > one :-) It is not that easy. The newly added vertices which belong to the red drawing line are not snap-able before the geometry is finalized. I usually digitize a separate point feature first for snapping and delete it later, or draw a polygon and convert it into line afterwards. I do not even think that it is a bug to not to snap into the vertices which belong to the drawing. Only occasion when it would be useful is precisely this case and it might indeed be good if the first vertex of the linestring that is under construction would be snap-able. However, the vertices in the middle of the drawing line should not be, IMHO. > In theory (OGC SimpleFeature) a closed Linestring is a Linestring with the > same start- and endpoint. If you have done this with the snapping function OJ > handels this two point as one point during a movement. And a Linearring is a > special case of a Linearring. You can read this in the JTS documentation: > http://tsusiatsoftware.net/jts/javadoc/com/vividsolutions/jts/geom/LineString.html > http://tsusiatsoftware.net/jts/javadoc/com/vividsolutions/jts/geom/LineString.html > Or take a look in the OGC document > https://portal.opengeospatial.org/files/?artifact_id=829 on page 2-1 figure > 2.1 and chapter 2.1.6 at page 2-5. Here you can read that a closed Linestring > a Linearring is. > With both (closed) geometries you cannot made a area computation! This is in > OJ only with a Polygon possible. Don't know why.... It is still just a line even it makes a loop and lines do not have area, just length. > Regards > Matthias Hi Uwe, 1) draw a polygon 2) select the item 3) right click ->Convert select geometies/layers to->LinearRing (or Linestring) Peppe 2015-04-08 15:21 GMT+02:00 Uwe Dalluege <uwe.dallu...@hcu-hamburg.de>: Hi, how can I draw a closed LineString (LinearRing)? When I try to catch the first point of the LineString with the last point of the same LineString OpenJUMP does not catch the first point. Is there a trick? Regards Uwe ------------------------------------------------------------------------------ BPM Camp - Free Virtual Workshop May 6th at 10am PDT/1PM EDT Develop your own process in accordance with the BPMN 2 standard Learn Process modeling best practices with Bonita BPM through live exercises http://www.bonitasoft.com/be-part-of-it/events/bpm-camp-virtual- event?utm_ source=Sourceforge_BPM_Camp_5_6_15&utm_medium=email&utm_campaign=VA_SF _______________________________________________ Jump-pilot-devel mailing list Jump-pilot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel ------------------------------------------------------------------------------ BPM Camp - Free Virtual Workshop May 6th at 10am PDT/1PM EDT Develop your own process in accordance with the BPMN 2 standard Learn Process modeling best practices with Bonita BPM through live exercises http://www.bonitasoft.com/be-part-of-it/events/bpm-camp-virtual- event?utm_ source=Sourceforge_BPM_Camp_5_6_15&utm_medium=email&utm_campaign=VA_SF _______________________________________________ Jump-pilot-devel mailing list Jump-pilot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel ------------------------------------------------------------------------------ BPM Camp - Free Virtual Workshop May 6th at 10am PDT/1PM EDT Develop your own process in accordance with the BPMN 2 standard Learn Process modeling best practices with Bonita BPM through live exercises http://www.bonitasoft.com/be-part-of-it/events/bpm-camp-virtual- event?utm_ source=Sourceforge_BPM_Camp_5_6_15&utm_medium=email&utm_campaign=VA_SF _______________________________________________ Jump-pilot-devel mailing list Jump-pilot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel
