PolyLabel still places center point outside some irregular geometry

[codingwithoutbugs]

This little bit of code is quite useful. Thanks for writing it. I found a few cases where the irregular geometries of feature still confuse the code and place the "center point" outside of the geometry. I'm tracking down the reason as best I can and will submit whatever I find. If one of you guys has a quicker route to fixing this than myself I'd gladly take that as well.

I'll attach the GEOJSON that can be used to reproduce the error.

{"name":"dbo.ICOOR","type":"FeatureCollection" ,"features":[ { "type":"Feature","geometry":{"type":"Polygon","coordinates":[[[-123.273625,49.3610850000001],[-123.274258,49.3612660000001],[-123.274735,49.3615070000001],[-123.275153,49.3618200000001],[-123.275551,49.3621840000001],[-123.275737,49.3624590000001],[-123.275855,49.3627650000001],[-123.275861,49.363161],[-123.275747,49.36373],[-123.275616,49.3642110000001],[-123.275515,49.3645940000001],[-123.275492,49.3652970000001],[-123.275571,49.365664],[-123.275692,49.365957],[-123.275861,49.3662830000001],[-123.275912,49.3665710000001],[-123.275873,49.366651],[-123.275788,49.366861],[-123.275402,49.3678840000001],[-123.274969,49.36884],[-123.274615,49.3694620000001],[-123.274245,49.369894],[-123.273793,49.3703180000001],[-123.273244,49.370706],[-123.272172,49.3712310000001],[-123.271774,49.3714650000001],[-123.270416,49.37244],[-123.269881,49.372918],[-123.269704,49.373143],[-123.269568,49.373548],[-123.269857,49.374645],[-123.269254,49.3769780000001],[-123.268865,49.37735],[-123.268584,49.3775890000001],[-123.268146,49.3780580000001],[-123.266609,49.3792130000001],[-123.266404,49.3795280000001],[-123.266175,49.38041],[-123.265683,49.381131],[-123.265409,49.3813930000001],[-123.265189,49.381537],[-123.264846,49.3817000000001],[-123.26402,49.381945],[-123.263704,49.3821070000001],[-123.263567,49.3822060000001],[-123.263004,49.382594],[-123.262497,49.3830090000001],[-123.260943,49.3836880000001],[-123.260792,49.383787],[-123.260148,49.38449],[-123.258927,49.3853740000001],[-123.256158,49.3881960000001],[-123.255899,49.388673],[-123.255725,49.3896810000001],[-123.255442,49.3909140000001],[-123.254923,49.3918590000001],[-123.25454,49.392391],[-123.254239,49.392724],[-123.253676,49.393175],[-123.251794,49.3944300000001],[-123.25141,49.3947370000001],[-123.250274,49.3958620000001],[-123.249319,49.3967850000001],[-123.248542,49.3975500000001],[-123.247974,49.398107],[-123.247079,49.399123],[-123.246589,49.3994760000001],[-123.246152,49.399776],[-123.245835,49.4000160000001],[-123.245701,49.4001950000001],[-123.244317,49.40112],[-123.243809,49.401526],[-123.243411,49.4019500000001],[-123.242975,49.4024890000001],[-123.242682,49.4028960000001],[-123.242316,49.403486],[-123.242146,49.403828],[-123.242058,49.404096],[-123.242061,49.4044870000001],[-123.242172,49.405069],[-123.242238,49.405353],[-123.242264,49.4056130000001],[-123.242234,49.4058910000001],[-123.241764,49.4068940000001],[-123.241679,49.407319],[-123.241601,49.407744],[-123.241536,49.408215],[-123.244232,49.408173],[-123.270444999,49.404594],[-123.288034999,49.3848850000001],[-123.29908,49.375297],[-123.292535,49.359316],[-123.278626,49.3433360000001],[-123.277399,49.332682],[-123.262672,49.325225],[-123.23281,49.33428],[-123.200085,49.3308180000001],[-123.168373999,49.3238880000001],[-123.168541,49.3252180000001],[-123.168093,49.327971],[-123.168086,49.3288900000001],[-123.168071,49.3299030000001],[-123.168059999,49.3306890000001],[-123.168061999,49.331625],[-123.168042999,49.3325980000001],[-123.168028,49.333602],[-123.168017,49.3341960000001],[-123.168012,49.3346320000001],[-123.168019999,49.3355250000001],[-123.167994,49.3364250000001],[-123.167985,49.337278],[-123.168019999,49.3382270000001],[-123.168000999,49.338779],[-123.168003999,49.3391280000001],[-123.167997,49.340024],[-123.167974,49.3409340010001],[-123.167980999,49.341038],[-123.16799,49.3418370000001],[-123.167951,49.3419180000001],[-123.167921999,49.3420180000001],[-123.167897,49.3421890000001],[-123.167872,49.342403],[-123.167857,49.34272],[-123.167846999,49.343146],[-123.167832,49.3436790000001],[-123.167825999,49.3439060000001],[-123.167823,49.344071],[-123.169233,49.3439450000001],[-123.170898,49.343805],[-123.172093,49.3437750000001],[-123.173445,49.343779],[-123.174346,49.343826],[-123.174979,49.3438770000001],[-123.175864,49.343965],[-123.176912,49.3441060000001],[-123.177676,49.344212],[-123.178424,49.3442930000001],[-123.178881,49.344322],[-123.180088,49.3443990000001],[-123.180892,49.344454],[-123.183843,49.3446250000001],[-123.184365,49.344663],[-123.184884,49.3447350000001],[-123.185302,49.3448270000001],[-123.18575,49.344954],[-123.186236,49.3451400000001],[-123.186726,49.34536],[-123.186884,49.3454390000001],[-123.186984,49.3455000000001],[-123.187256,49.3456620000001],[-123.188453,49.3463530000001],[-123.18909,49.346664],[-123.189654,49.346906],[-123.190154,49.3470590000001],[-123.190794,49.3471740000001],[-123.191209,49.3472110000001],[-123.191936,49.3472640000001],[-123.19271,49.347311],[-123.193393,49.3473320000001],[-123.194114,49.3473450000001],[-123.194774,49.3473530000001],[-123.195678,49.3473320000001],[-123.196919,49.347296],[-123.198029,49.347223],[-123.201019,49.3469940000001],[-123.208887,49.3462920000001],[-123.210389,49.3461810000001],[-123.211813,49.3461300000001],[-123.212968,49.3461380000001],[-123.214052,49.346168],[-123.215005,49.346215],[-123.216324,49.346303],[-123.218799,49.346456],[-123.219965,49.3465630000001],[-123.222048,49.3468930000001],[-123.226067,49.347905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]}

[mourner]

Interesting, can you show a screenshot of the shape along with the point polylabel calculates?

[codingwithoutbugs]

Sorry for the delay in response. Here is a screen capture of it. I've noticed a number of places that have this issue (only a small number). Out of a dataset of approx. 860, there were only a few that polylabel couldn't figure out. If you need further examples let me know and I'll package them up.

[codingwithoutbugs]

I'm also including an example of PolyLabel working with other irregular geometric shapes. It seems only a few could stump it. Almost all the others are fine.

[mourner]

Thanks! I'll investigate. This certainly doesn't look right.

[codingwithoutbugs]

Oopps. I didn't mean to close this.

[codingwithoutbugs]

Thanks mourner. Let me know if there's anything I can do. I was about to make a debug version of this just to show all the points and boxes being plotted before best point is determined but work got me on other projects for a few days. I'm quite interested to see what the solution is.

[mourner]

@codingwithoutbugs what value do you use for polylabel precision on those polygons? Can you try something like 0.001 or smaller? It looks like the results above were produced with the default precision of 1, which doesn't fit the input coordinates range (where 1 degree lat/lng is a big distance).

[codingwithoutbugs]

The 0.001 worked. I had not gone down to that level of precision. Thank you for pointing it out.