#169 Create a single polygon from multiple contiguous areas

open
nobody
5
2012-05-14
2012-05-13
Andrei_n
No

A new function for the "Create polygon from closed area". If holding the "Shift" key (for example) and clicking over multiple closed areas, the result would be a single polygon merging all the closed areas you selected.

Discussion

  • mentaer
    mentaer
    2012-05-13

    Hei Andrei, I do not understand your wish.
    Can you deliver an image?

    As a note: merging polygon with space in-between isn't an easy thing.. and there probably several solutions possible. However, if there is no space - you would use the "Merge Two Polygons" function from the Tools>Edit Geometry menu.
    If you ask why we support only 2 geometries once at the time it is because something needs to be done with the attributes... and only for 2 polys it is "traceable".

    stefan

     
  • Stefan,
    "Create polygon from closed area" creates a single polygon from a set of noded linestrings. As I understand, Andrei would like to fill several contiguous areas to build one single polygon.

    Merging polygons after is also possible, but this is a second action (not as efficient as what Andrei asks for what he wants). By the way, do you know that I added a "merge polygons" in the context menu which can merge several polygons (of course, some attribute values are lost if features have different values)

     
  • Andrei_n
    Andrei_n
    2012-05-14

    Michael is right. I want to fill multiple contiguous closed areas with a single polygon.

    If you wonder where this function would be useful, I have attached a screen capture to this report. There I have a polygon area with the administrative limits of several (Transylvanian) counties in 1925 (green). I need to update those counties to their 1937 limits and I have used linestrings to mark the detached parts. Now I want a new polygon layer (purple) to contain the 1937 counties.

    Of course I can create several polygons from the closed areas, then merge them using right click->merge selected features, but this path is more time consuming.

     
  • Andrei_n
    Andrei_n
    2012-05-14

    • summary: Create a single polygon from multiple closed areas --> Create a single polygon from multiple contiguous areas