Global Mapper Pro

find intersections of selected area features

amihay_h
amihay_h Global Mapper User
edited January 2013 in Vector Data
Dear sir.
im trying to "find intersections of selected area features" on several polygons SHP's, but i can do so only to not more than 2 polygons.
i need to do that on multiple polygons which not all of them have intersections. and some of the intersection will be more than 3-5 polygons
is there any way i could do it ?
im using the "Global Mapper 11.00 or 11.01"
thanks ...
Amihay

Comments

  • global_mapper
    global_mapper Administrator
    edited February 2012
    Amihay,

    You can directly find the intersection of just 2 polygons, but you can crop any collection of features to a single polygon (i.e. find the intersection of a bunch of features to that polygon) by exporting cropped to that polygon. In v13 there is also a new option to do such a crop directly in the Digitizer Tool.

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.globalmapper.com
  • Flugwerk
    Flugwerk Global Mapper User
    edited January 2013
    Mike,
    I'm trying to do the same in v14. I want to find intersections of all areas between two overlays (shapefiles) with alot of areas/polygons inside. Additionally I want to have all attributes of intersected areas combined in the newly created areas. Areas outside of intersections should not be deleted.
    Any idea how to do this?

    regards, Heinrich
  • global_mapper
    global_mapper Administrator
    edited January 2013
    If you have the latest v14, you can select all of the areas in one layer, then right-click in the Digitizer Tool and choose the crop submenu item to crop loaded features to the selected areas. Then select to crop just the areas and assign to a new layer. This should give you all of the cropped results in a new area. Note you might want the latest build to do this as we have enhanced this since the v14.0 release. I have placed a new build at http://www.bluemarblegeo.com/downloads/global-mapper/global_mapper14.zip with the latest changes for you to try. Simply download that file and extract the contents into your existing v14.xx installation folder to give it a try. If you are using the 64-bit v14 version there is a new build at http://www.bluemarblegeo.com/downloads/global-mapper/global_mapper14_64bit.zip .

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.bluemarblegeo.com/
  • Flugwerk
    Flugwerk Global Mapper User
    edited January 2013
    Mike,
    Thank you for your help but this cropping feature is somehow mysterious to me. How can I select which layer ist the cropping one and which layer is cropped to? Whatever I click, select or do, everytime I get the same result.
    In a first step I store the result of cropping into a new layer. In a second step I want to crop inversed to get the remaining cropped (cut out) areas as a result. Its hard to explain, maybe you can imagine the picture.

    Regards, Heinrich
  • global_mapper
    global_mapper Administrator
    edited January 2013
    The cropping is done to whatever area(s) that you have selected. So if you want to crop to a particular layer of areas, first right-click on that layer in the Control Center and select the option to select all of the features with the Digitizer Tool. You can then do the crop and everything else will be cropped to those selected areas from that layer.

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.bluemarblegeo.com/
  • Flugwerk
    Flugwerk Global Mapper User
    edited January 2013
    Mike,
    I attached a sketch showing my problem:
    I have two layers, Blue and Red. In step 1 cropping works fine - I get the resulting blue areas.
    In the second step I want to get the remaining blue areas but I'm not able to do so. I tried to crop in every direction but everytime I get the result as shown in step 1.

    How can I get the result from step 2?

    Regards, Heinrich


    cropping.jpg
  • global_mapper
    global_mapper Administrator
    edited January 2013
    There is an option on the crop dialog to keep the data outside rather than inside. Just check that and you will get the blue areas, in affect cutting away the red areas.

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.bluemarblegeo.com/
  • Flugwerk
    Flugwerk Global Mapper User
    edited January 2013
    Mike,
    I already tried this but then I get multiple copies of the blue polygons, one for every intersection with a red polygon.

    Regards, Heinrich
  • global_mapper
    global_mapper Administrator
    edited January 2013
    Are you using the latest build of Global Mapper v14 (should say v14.1 in the title bar)? We made improvements to this to try and handle crops to multiple areas at once after the last official v14 release. I have placed a new build at http://www.bluemarblegeo.com/downloads/global-mapper/global_mapper14.zip with the latest changes for you to try. Simply download that file and extract the contents into your existing v14.xx installation folder to give it a try. If you are using the 64-bit v14 version there is a new build at http://www.bluemarblegeo.com/downloads/global-mapper/global_mapper14_64bit.zip .

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.bluemarblegeo.com/
  • Flugwerk
    Flugwerk Global Mapper User
    edited January 2013
    Mike,
    I tried with the version from your last post and it still doesn't work. Maybe you can try it yourself. Keeping the outside data doesn't work, it produces multiple copy of areas.

    Regards, Heinrich
  • Flugwerk
    Flugwerk Global Mapper User
    edited January 2013
    Mike,

    I attached a sketch again to show what's happening. Instead of producing the shape as supposed shown in Fig.1 it produces 2 stacked shapes as in Fig.2

    Regards, Heinrich

    cropping1.jpg
  • global_mapper
    global_mapper Administrator
    edited January 2013
    I have updated the subtraction process so that the duplicates aren't created when multiple crop areas overlap the areas being cropped. I have placed a new build at http://www.bluemarblegeo.com/downloads/global-mapper/global_mapper14.zip with the latest changes for you to try. Simply download that file and extract the contents into your existing v14.xx installation folder to give it a try. If you are using the 64-bit v14 version there is a new build at http://www.bluemarblegeo.com/downloads/global-mapper/global_mapper14_64bit.zip .

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.bluemarblegeo.com/
  • Flugwerk
    Flugwerk Global Mapper User
    edited January 2013
    Mike,
    Thank you for the quick help. I tried the new version but I get this error message:

    "One ore more of the areas being cropped is invalid and cannot be cropped"

    Are there any restrictions for the areas being cropped? I have big layers with lots of ares, some with holes.

    Regards, Heinrich
  • global_mapper
    global_mapper Administrator
    edited January 2013
    Heinrich,

    Holes are fine, but the areas do have to be valid geometries (i.e. no self-intersections, no overlapping holes, no holes outside parent). Typically self-intersecting areas are the most common invalid geometry.

    We are planning on adding a feature to automatically detect and fix self-intersecting polygons so that they can be cropped, but for now they have to be valid up front.

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.bluemarblegeo.com/
  • Flugwerk
    Flugwerk Global Mapper User
    edited January 2013
    Mike,
    I cannot check this huge amount of data for intersections by hand, do you have any idea when this functionallity will be implemented in Globalmapper? Or can you recommend any tool for checking and auto-correcting my shapefiles?

    Regards, Heinrich
  • global_mapper
    global_mapper Administrator
    edited January 2013
    Heinrich,

    Hopefully we will have it in Global Mapper in the next few months. The code for finding the invalid polygons already exists internally, we just have to expose it and add the automatic fixing of problems.

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.bluemarblegeo.com/
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