Areas partially filled (180° longitude issue?), calculation off by exactly 1000 sq km

Jake
Jake Global Mapper UserTrusted User
edited July 2012 in Bug Report
GM 13.2 (b071212) Win XP Pro 32

Attached is an example of what I am seeing in some of my areas. The projection is polar stereographic. The areas that straddles the 180th meridian is only partially filled. The area outline seems to be drawn correctly but the area calculation is off by 1000 sq km.

Comments

  • global_mapper
    global_mapper Administrator
    edited July 2012
    The area calculations are going to be done in the view projection system (polar stereographic in this case). The actual area covered by a figure varies depending on the projection you are viewing it in as the shape of the lines between vertices on the ground can be different (often negligibly) unless going long distances. How did you calculate the expected area? Just from the area of a circle?

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.globalmapper.com
  • Jake
    Jake Global Mapper User Trusted User
    edited July 2012
    Actually I just queried the area features (range ringe) and they were all the same size except for one. They should all be approximately the same and they have plenty of vertices to maintain its shape regardless of projection.
  • Jake
    Jake Global Mapper User Trusted User
    edited July 2012
    I think I may have resolved the area size issue. I updated the measure attributes and they are a lot closer. Now the difference is most likely due to scale change in the map projection. The incomplete fill issue still exists.
  • global_mapper
    global_mapper Administrator
    edited July 2012
    I fixed the issue with the missing render as well, so now everything should be ok. I have placed a new build at http://www.globalmapper.com/global_mapper13.zip with the latest changes for you to try. Simply download that file and extract the contents into your existing v13.xx installation folder to give it a try. If you are using the 64-bit v13 version there is a new build at http://www.globalmapper.com/global_mapper13_64bit.zip .

    Let me know if I can be of further assistance.

    Thanks,

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

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