2

I am trying to upload a set of polygons to an online map interface and I keep coming across the error that there are duplicate vertices. What does this mean? Below are the coordinates for all vertices - none of them are duplicates. Are the coordinates being read in such a way that the map interface identifies them as duplicates?

In QGIS 3.01 there is a tool called "Remove Duplicate Vertices" - would this fix the problem? What exactly is that program doing?

{
        "type" : "MultiPolygon",
        "coordinates" : [ 
            [ 
                [ 
                    [ 
                        -70.0701131646022, 
                        41.3018717290655
                    ], 
                    [ 
                        -70.0695692509758, 
                        41.3017748127887
                    ], 
                    [ 
                        -70.0694138945647, 
                        41.3019469427903
                    ], 
                    [ 
                        -70.0699260732008, 
                        41.3023729296374
                    ], 
                    [ 
                        -70.0711995865773, 
                        41.3024193924651
                    ], 
                    [ 
                        -70.0711188261137, 
                        41.3019703207653
                    ], 
                    [ 
                        -70.0705569161245, 
                        41.3019808729848
                    ], 
                    [ 
                        -70.0702193526153, 
                        41.302327284902
                    ], 
                    [ 
                        -70.0695003876873, 
                        41.302007602561
                    ], 
                    [ 
                        -70.0695771899608, 
                        41.3018127948566
                    ], 
                    [ 
                        -70.0700379374792, 
                        41.3018967257557
                    ], 
                    [ 
                        -70.0701639937583, 
                        41.3018213369312
                    ], 
                    [ 
                        -70.06973894872, 
                        41.3014277964702
                    ], 
                    [ 
                        -70.0709060142191, 
                        41.3011933232562
                    ], 
                    [ 
                        -70.0737300988847, 
                        41.3012783209664
                    ], 
                    [ 
                        -70.0771252198893, 
                        41.3002234628503
                    ], 
                    [ 
                        -70.0779060689831, 
                        41.3008255161259
                    ], 
                    [ 
                        -70.0732960038241, 
                        41.3027561707173
                    ], 
                    [ 
                        -70.0707831225804, 
                        41.3032116865641
                    ], 
                    [ 
                        -70.0649346272725, 
                        41.3064585560801
                    ], 
                    [ 
                        -70.0642214360789, 
                        41.305952237009
                    ], 
                    [ 
                        -70.0659680798512, 
                        41.3012176637636
                    ], 
                    [ 
                        -70.0665796974536, 
                        41.3011195188198
                    ], 
                    [ 
                        -70.0681199286715, 
                        41.3016240245165
                    ], 
                    [ 
                        -70.069294825242, 
                        41.3014451094747
                    ], 
                    [ 
                        -70.0701131646022, 
                        41.3018717290655
                    ]
                ]
            ], 
            [ 
                [ 
                    [ 
                        -70.0650414062583, 
                        41.3065474919442
                    ], 
                    [ 
                        -70.0708438634056, 
                        41.3033146613653
                    ], 
                    [ 
                        -70.0710448056788, 
                        41.3039599412883
                    ], 
                    [ 
                        -70.0654671971062, 
                        41.3072402476146
                    ], 
                    [ 
                        -70.0565381111194, 
                        41.3136569383435
                    ], 
                    [ 
                        -70.0555079431789, 
                        41.3127228062139
                    ], 
                    [ 
                        -70.0626923875053, 
                        41.3083213513054
                    ], 
                    [ 
                        -70.0650414062583, 
                        41.3065474919442
                    ]
                ]
            ], 
            [ 
                [ 
                    [ 
                        -70.062412836902, 
                        41.3083503910663
                    ], 
                    [ 
                        -70.0584956802755, 
                        41.3107461409579
                    ], 
                    [ 
                        -70.0558528833142, 
                        41.3082981275069
                    ], 
                    [ 
                        -70.0554761116255, 
                        41.3071685923142
                    ], 
                    [ 
                        -70.056311112425, 
                        41.3079531250911
                    ], 
                    [ 
                        -70.0574841709639, 
                        41.3084705704457
                    ], 
                    [ 
                        -70.0598839690538, 
                        41.3086366712089
                    ], 
                    [ 
                        -70.0620005953469, 
                        41.307880089493
                    ], 
                    [ 
                        -70.062412836902, 
                        41.3083503910663
                    ]
                ]
            ], 
            [ 
                [ 
                    [ 
                        -70.0812183874257, 
                        41.2986925625239
                    ], 
                    [ 
                        -70.0822656353255, 
                        41.2984004397372
                    ], 
                    [ 
                        -70.0831476314588, 
                        41.2988393332178
                    ], 
                    [ 
                        -70.0826437458626, 
                        41.2994561762623
                    ], 
                    [ 
                        -70.0733523489924, 
                        41.3028359494404
                    ], 
                    [ 
                        -70.0782883991418, 
                        41.3007955083111
                    ], 
                    [ 
                        -70.0812183874257, 
                        41.2986925625239
                    ]
                ]
            ], 
            [ 
                [ 
                    [ 
                        -70.0790217174606, 
                        41.2980439315427
                    ], 
                    [ 
                        -70.0808194860124, 
                        41.2988263197269
                    ], 
                    [ 
                        -70.0781984672347, 
                        41.3007026790876
                    ], 
                    [ 
                        -70.0773421834121, 
                        41.3000879999602
                    ], 
                    [ 
                        -70.0790217174606, 
                        41.2980439315427
                    ]
                ]
            ], 
            [ 
                [ 
                    [ 
                        -70.0794959073143, 
                        41.2970966884074
                    ], 
                    [ 
                        -70.079510321156, 
                        41.2970481985422
                    ], 
                    [ 
                        -70.0821087382947, 
                        41.298322487249
                    ], 
                    [ 
                        -70.081173589866, 
                        41.2985844645755
                    ], 
                    [ 
                        -70.079208222021, 
                        41.2976915572271
                    ], 
                    [ 
                        -70.0794959073143, 
                        41.2970966884074
                    ]
                ]
            ], 
            [ 
                [ 
                    [ 
                        -70.062834179621, 
                        41.3073250775624
                    ], 
                    [ 
                        -70.0631943592857, 
                        41.3070080194244
                    ], 
                    [ 
                        -70.0637259373095, 
                        41.3073905381303
                    ], 
                    [ 
                        -70.0627092782336, 
                        41.3081766646363
                    ], 
                    [ 
                        -70.0623089479922, 
                        41.3076941224421
                    ], 
                    [ 
                        -70.062834179621, 
                        41.3073250775624
                    ]
                ]
            ]
        ]
    }
  • Welcome to gis.stackexchange! Please edit the title of your question to include enough information for future visitors to be able to find this thread when looking for the same problem. – underdark May 1 '18 at 20:13
  • Note that your coordinates are asserting a precision measured in Angstroms, so even if there weren't duplicates, the differences might only matter if you were mapping logic gates in a CPU die. – Vince May 2 '18 at 3:39
5

Here are the duplicates. Hope this helps. Maybe try that tool also? Have not seen this error before, but it just seems that the error is being generated due to spatially coincident points.

Dupe pts

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