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modify concave hull creation similar to "combine areas" function

JSL
JSL Global Mapper UserTrusted User
in Suggestion Box
I have a layer with groups of points that are separated from each other.  It would be great if there was an option on the "create coverage area (concave hull)" function that would allow allow me to create individual hulls by a particular characteristic, like say color, or a country label.  It would be similar to the "combine areas" feature that allows you to only combine areas depending on what option you choose, like those that have the same feature name.

RIght now, the function creates a hull around all the points in the layer, regardless of how separated they are.  I know I could create individual layers and perform the function on each layer, but there are a lot of points, and that would be a lot of clicking.

Thanks for any help...

Answers

  • 946
    946 Global Mapper User Trusted User
    Hi,
    If I understood well,i guess you coud create lines from points using a maximum distance (assuming the distance between groups is bigger than the distances between the points of each group)and after create areas from lines, 
  • JSL
    JSL Global Mapper User Trusted User
    The problem is that the "create lines" function works like the "create concrete hull" function, where it creates lines from all the selected points, regardless of layer.  I need it to perform the function on all the points, but selectively by a certain attribute, so, for example, all blue points would be one hull, etc.
  • bmg_bob
    bmg_bob Global Mapper Programmer
    Hello,

    Just to make sure I understand:

    You are talking about the Digitizer function Create Area/Polygon Features |  Create Coverage Area (Concave Hull) for Selected Feature(s)... and you want to create a concave hull for groups of attributes that have the same value for a specified attribute name (instead of for the selected features).  Is this correct?

    Presumably, this would apply to the Control Center's BBOX/COVERAGE function also.

    Cheers,
    Bob
  • JSL
    JSL Global Mapper User Trusted User
    That would be fantastic.  Currently you can combine areas by a specific attribute, it would be great to be able to do the same with the functions you described.
  • bmg_bob
    bmg_bob Global Mapper Programmer
    Hello,

    I have added feature request #19735 to our task list so we can evaluate including the ability to create concave hulls for groups of features that share an attribute value in a future version of Global Mapper.  We will post a message on this thread when the status of the feature request changes.

    Cheers,
    Bob

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