[GRASS-user] traveling salesman problem in air
Dear GRASS experts! I encountered an interesting problem and am curious about solutions. A helicopter company has got a file from a client regarding a forest inventory. The file contains 1430 polygons representing areas to be visited. Now we want to calculate the optimal route to visit all polygons. In contrast to a traveling salesman , we don't have a network of routes as the helicopter can fly everywhere. Would it be a solution to have the distance betweeen areas as the cost? I used a tool in MapInfo that connects successive closest points which worked very nice but not optimal. Anyone knows of other solutions? Regards, Martina ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] traveling salesman problem in air
Yes, the centroids should be fine. it actually did not work to run v.net.visibility when I tried but I'll give it another try with the centroids. Thanks! Martina Moritz Lennert skrev: On 15/04/09 09:19, Wolf Bergenheim wrote: On 15.04.2009 10:05, Moritz Lennert wrote: On 15/04/09 08:55, Martina Schäfer wrote: Dear GRASS experts! I encountered an interesting problem and am curious about solutions. A helicopter company has got a file from a client regarding a forest inventory. The file contains 1430 polygons representing areas to be visited. Now we want to calculate the optimal route to visit all polygons. In contrast to a traveling salesman , we don't have a network of routes as the helicopter can fly everywhere. Would it be a solution to have the distance betweeen areas as the cost? I used a tool in MapInfo that connects successive closest points which worked very nice but not optimal. Anyone knows of other solutions? Maybe v.net.visibility to create a network and then v.net.salesman ? Exactly what I was going to suggest. the network created by v.net.visibility will connect all polygon nodes to all visible polygon nodes. The net will then consist of of these points plus the edges that make up the polygons. Depending on the size of the polygons and of the whole area, I imagine that this could be simplified by just using the centroids of the polygons, or ? Moritz ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] problems with i.rectify
Hi , just want to add that when I rectified the next image the same error appeared again - the first band in the group is not rectified as it is not found. I lured the programme now by adding an additional band from a similar image to the group and put it in first place , so that this band is not rectified/found but the three bands of my image are... regards, Martina Martina Schäfer skrev: Hi again! I installed GRASS 6.4 and first I got the same error. Then, I tried with defining a new group and subgroup in the XY mapset (not using the one that is created when importing) and with that it worked!! However, I also tried using wxpython, which looks neat, but there I get the error message that the group does not exist (but it certainly does). Best, Martina Markus Neteler skrev: hi Martina, On Thu, Apr 2, 2009 at 9:28 AM, Martina Schäfer martina.scha...@ebc.uu.se wrote: Hello Markus, thanks for the reply! And thanks for the tip on i.orto.photo, I will read through your article! I've followed the instructions and everything's working fine except that the red band is not included. In the output it says : Rectified input file NN1_2.red will be saved as NN1_2.red 1257 I see a suspicious white space before 1257. Where does it come from? Could it be that it crept in when defining the group? Well, the space was my fault and a typing mistake, it really says NN1_2.red1257, so no error there. ah ok, perfect. In the mapset there is a group/ directory in which the group is defined (ASCII file). The easiest way is to check there/fix if the red channel was defined properly. I looked in the group folder and found a file REF where all bands are properly named. Was that the file you meant? Yes, fine. The group is defined in the XY location. In the projected location it does not exist prior to rectifying. BTW: which GRASS version and which operating system? I'm using GRASS 6.3. downloaded from http://grass.bologna.enea.it/ on Mac OS X 10.5.6 I recall that we fixed some issues later. Could you upgrade to 6.4RC3 instead? http://grass.osgeo.org/download/index.php#g64x If it still fails we may be able to fix it for 6.4.0 final. best Markus ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] problems with i.rectify
Hi again! I installed GRASS 6.4 and first I got the same error. Then, I tried with defining a new group and subgroup in the XY mapset (not using the one that is created when importing) and with that it worked!! However, I also tried using wxpython, which looks neat, but there I get the error message that the group does not exist (but it certainly does). Best, Martina Markus Neteler skrev: hi Martina, On Thu, Apr 2, 2009 at 9:28 AM, Martina Schäfer martina.scha...@ebc.uu.se wrote: Hello Markus, thanks for the reply! And thanks for the tip on i.orto.photo, I will read through your article! I've followed the instructions and everything's working fine except that the red band is not included. In the output it says : Rectified input file NN1_2.red will be saved as NN1_2.red 1257 I see a suspicious white space before 1257. Where does it come from? Could it be that it crept in when defining the group? Well, the space was my fault and a typing mistake, it really says NN1_2.red1257, so no error there. ah ok, perfect. In the mapset there is a group/ directory in which the group is defined (ASCII file). The easiest way is to check there/fix if the red channel was defined properly. I looked in the group folder and found a file REF where all bands are properly named. Was that the file you meant? Yes, fine. The group is defined in the XY location. In the projected location it does not exist prior to rectifying. BTW: which GRASS version and which operating system? I'm using GRASS 6.3. downloaded from http://grass.bologna.enea.it/ on Mac OS X 10.5.6 I recall that we fixed some issues later. Could you upgrade to 6.4RC3 instead? http://grass.osgeo.org/download/index.php#g64x If it still fails we may be able to fix it for 6.4.0 final. best Markus ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] problems with i.rectify
Hello Markus, thanks for the reply! And thanks for the tip on i.orto.photo, I will read through your article! I've followed the instructions and everything's working fine except that the red band is not included. In the output it says : Rectified input file NN1_2.red will be saved as NN1_2.red 1257 I see a suspicious white space before 1257. Where does it come from? Could it be that it crept in when defining the group? Well, the space was my fault and a typing mistake, it really says NN1_2.red1257, so no error there. In the mapset there is a group/ directory in which the group is defined (ASCII file). The easiest way is to check there/fix if the red channel was defined properly. I looked in the group folder and found a file REF where all bands are properly named. Was that the file you meant? The group is defined in the XY location. In the projected location it does not exist prior to rectifying. BTW: which GRASS version and which operating system? I'm using GRASS 6.3. downloaded from http://grass.bologna.enea.it/ on Mac OS X 10.5.6 Best, Martina ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] problems with i.rectify
Hi everybody! I'm a rather new GRASS user and encountered problems using i.rectify to rectify aerial images taken from helicopter. I've followed the instructions and everything's working fine except that the red band is not included. In the output it says : Rectified input file NN1_2.red will be saved as NN1_2.red 1257 unable to find NN1_2.red1257 in permanent. it nevertheless continues with: Rectify NN1_2.redinto NN1_2.red1257... complete the green and blue band are rectified without problems and look fine. Any help is greatly appreciated!! /Martina -- Martina Schfer, PhD GIS och bekmpningsansvarig forskare Biologisk Myggkontroll Uppsala universitet, Inst. f ekologi och evolution; populationsbiologi och naturvrdsbiologi Norbyvgen 18D, 752 36 Uppsala Tel: 018-4712674, 070-4250605 Fax: 018-4716424 http://www.popbiol.ebc.uu.se/ www.mygg.se ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
