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  • 1.  Smaller polygons within polygon

    Posted 09-28-2022 15:53
    Edited by Fanny Chan 09-28-2022 15:54
    Is there a function I can use that can help me merge these smaller polygons to the polygon they contain within?

    I've used something like Union in ArcGIS, but I'm trying to find a solution on MapInfo that would do the same? Since there are many of these scattered throughout the tab file, I don't want want to manually combine selected objects.

    Also, theres no similar ID I can use to merge them either, so it would have to be something like a spatial join.



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    Fanny Chan

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  • 2.  RE: Smaller polygons within polygon

    Employee
    Posted 09-29-2022 03:09
    Hi Fanny

    Are the smaller polygons fully contained in the bigger polygons?
    Do you need to combine them or could you just delete them?

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    Peter Horsbøll Møller
    Principal Presales Consultant | Distinguished Engineer
    Precisely | Trust in Data
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  • 3.  RE: Smaller polygons within polygon

    Posted 09-29-2022 10:23
    I would like to delete them since they are empty.

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    Fanny Chan
    Knowledge Community Shared Account
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  • 4.  RE: Smaller polygons within polygon

    Employee
    Posted 09-30-2022 03:43
    I wonder if you can select them all by size. They all look way smaller than the polygons they lie inside.

    Can you try to run a query like this from the Simple Select dialog

    Select your table from the Select Records from Table list and paste this condition into the that Satisfy: field: Area(obj, "sq m") < 1000

    You might have to change the size (1000) to a value that matches the sizes of your small polygons.

    You can also use the SQL Window if you prefer:
    Select *
    From Polygons
    Where Area(Obj, "sq m") < 1000
    Into Selection

    Replace Polygons with the name of your table


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    Peter Horsbøll Møller
    Principal Presales Consultant | Distinguished Engineer
    Precisely | Trust in Data
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  • 5.  RE: Smaller polygons within polygon

    Posted 09-30-2022 04:18
    Hi Fanny and Peter,

    If they are "empty", perhaps they can be selected by attribute?

    However, they look like text object to me.  In that case, they can be selected via the following SQL (using the MapBasic or SQL Window):

    Select *
    From Polygons
    Where str$(obj)="text"
    Into Selection

    Then delete the selection.

    If they are not text objects they might be labels?  Try turning labels off for that layer.

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    James Nolet
    Dooley Mitchell & Morrison Pty Ltd
    Mentone, VIC, Australia
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