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Removing an internal line from Polygon

  • 1.  Removing an internal line from Polygon

    Posted 23 days ago
    Edited by Richard Sherman 23 days ago
    Dear All,

    I'm using Mapinfo Pro 17.4.

    I would like to know how to remove an internal line within a polygon. However, I am not sure if this is possible? As in to leave the polygon with just the remaining sides showing - as in the below image?


    Thanks

    Richard

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    Richard Sherman
    United Kingdom
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  • 2.  RE: Removing an internal line from Polygon

    Posted 23 days ago
    Hi Richard

    You can add each of the two polygons twice to the map.

    One set of the two layers, the under set, you set the fill style and use an "invisible" line style.
    For the other set, the upper set, you only set a very thick line style.

    In my example below, I have grouped using the Layer Group to clarify the idea.
    You can use different colors for line style and for fill style if you want.

    I have only chosen different fill colors.


    ------------------------------
    Peter Horsbøll Møller
    Principal Presales Consultant | Distinguished Engineer
    Precisely | Trust in Data
    ------------------------------



  • 3.  RE: Removing an internal line from Polygon

    Posted 22 days ago
    Hi Peter,

    Thanks v much for this.

    I don't understand about adding the 2 polygons to the map twice though? As in just copying the polygons to a new layer? So have 4 layers instead of 2?

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    Richard Sherman
    United Kingdom
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  • 4.  RE: Removing an internal line from Polygon

    Posted 22 days ago
    Hi Richard

    In my example, I have manually selected one of the polygons and added the selection to the map.
    Then I manually selected the other polygon and added the new selection to the map again.

    When I add the selection to the map, the selection gets a "sticky" query name like Query1, Query2, or similar.

    I'm just creating selections. I'm not copying the polygons to new layers/tables. I hope you can see this from the Layer List on the left in the image above.

    ------------------------------
    Peter Horsbøll Møller
    Principal Presales Consultant | Distinguished Engineer
    Precisely | Trust in Data
    ------------------------------



  • 5.  RE: Removing an internal line from Polygon

    Posted 22 days ago
    Hi Peter,

    I see yes, I have managed to do that now, doing a Query but unfortunately I can't seem to get it how I want it to look as what I am after is the internal line showing but that internal line is a boundary of another layer so - is that possible to still show or not?

    Thanks.

    ------------------------------
    Richard Sherman
    United Kingdom
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  • 6.  RE: Removing an internal line from Polygon

    Posted 22 days ago
    Can you share a screenshot of your map and the layer list?

    I need to get a view of what you are trying to do with what layers. If you can turn off the layers in the layer list that aren't important for this that would also be helpful. And give the layers different colors via Style Override so that we easily can see how the layers are shown.

    ------------------------------
    Peter Horsbøll Møller
    Principal Presales Consultant | Distinguished Engineer
    Precisely | Trust in Data
    ------------------------------



  • 7.  RE: Removing an internal line from Polygon

    Posted 20 days ago
    Hi Peter,

    Ok, I've done a screenshot as below: Therefore, to keep the existing Black 'SD_1' line but remove the 'Query 4 and Query 5' lines that cross the SD1 middle boundary line.



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    Richard Sherman
    United Kingdom
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  • 8.  RE: Removing an internal line from Polygon

    Posted 17 days ago
    Hi Richard,

    If you want to remove the black line that touches the red and yellow polygons, you probably want to select the yellow and red polygons and "combine objects". Once that layer is created, you can overlay that on the larger green polygon. If you want the separate colors for those polygons, then you can bring in just one of those polygons and layer it on top of that new, combined polygon with the border lines removed (like Peter mentioned earlier).

    When you combine the two polygons, you may notice some bits and pieces of that black line. I've found in order to clear that up, you can disaggregate that polygon and uncheck the "retain holes in regions", then combine them again. Or you can clean the new polygon to get rid of the remaining black line residue.

    Hope this helps.​

    ------------------------------
    Chris Clukey
    Senior Planning Analyst
    Mount Carmel Health System
    Columbus, Ohio USA
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  • 9.  RE: Removing an internal line from Polygon

    Posted 17 days ago
    Hi Chris,

    Many thanks for your reply.

    However, I wanted to keep the black line, and remove the underlying blue and red lines that intersect the black one. Ah yes I have tried combing both polygons but unfortunately I couldn't find a way of just keeping the black line.

    ------------------------------
    Richard Sherman
    United Kingdom
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  • 10.  RE: Removing an internal line from Polygon

    Posted 17 days ago
    If you don't care if the boundary lines are the same, you could just make the black boundary line thicker or the red/blue lines thinner.

    Are the blue/red polygons based on the same geographic boundaries as the black, or are the blue/red polygons freehand? I'm wondering why there as much overlap between all three colors.

    ------------------------------
    Chris Clukey
    Senior Planning Analyst
    Mount Carmel Health System
    Columbus, Ohio USA
    ------------------------------