Polygon divider creates less equal parts than asked

[IriniKape]

I've installed QGIS 3.16 for Windows. I digitised a polygon layer (limits of a city) and used the Polygon divider plugin to divide it in 10 equal parts (polygons).

However, as a result, it created only 9 equally divided polygons. (When I tested it, asking for 9 equal parts, it did create 9 polygons (2 of them weren' t equal though). But when I tried for an 8 equal parts division, it again gave 7 (ie. minus 1) polygons). So it seems that for a number of divisions it does the job, for others not.

Could you please enlighten me? Thank you in advance!

[jonnyhuck]

Unfortunately, due to the complexity of what it is doing, its performance can vary depending on the geometry of the shape that you are trying to subdivide - though it would more usually have one too many polygons (due to an unintentional offcut - normally a tiny sliver) rather than one too few - could you send a copy of the data so I can try and reproduce it please?

An easy fix might be to simply change the direction of cut - it will perform differently in each direction, so that might resolve it for you!

[IriniKape]

GLADLY, THANK YOU!!!
It is for an urban project, in Greece, ultimately, I need to create the centroids of these 10 polygons.
Irene

Oria_polis.zip

Unfortunately, due to the complexity of what it is doing, its performance can vary depending on the geometry of the shape that you are trying to subdivide - though it would more usually have one too many polygons (due to an unintentional offcut - normally a tiny sliver) rather than one too few - could you send a copy of the data so I can try and reproduce it please?

An easy fix might be to simply change the direction of cut - it will perform differently in each direction, so that might resolve it for you!

[IriniKape]

Thank you very much for taking the trouble and sending me your reflections. I did try a few alternatives and realised that maybe the shape of my polygon was indeed quite complex and irregular. So, I digitised it again but (quite) more roughly and yes, the plugin worked properly and effectively. However, since I really need it for an urban planning project (the polygon is actually the limits of a medium sized city in Greece, EU, where I need to create the respective centroids), I will respond to your kind suggestion and send you the original polygon. Looking forward to hearing from you, Irene PS. I think I should remind you I try to divide it in 10 polygons.

…

On Tue, Dec 1, 2020 at 6:40 PM Jonny Huck ***@***.***> wrote: Unfortunately, due to the complexity of what it is doing, its performance can vary depending on the geometry of the shape that you are trying to subdivide - though it would more usually have one too many polygons (due to an unintentional offcut - normally a tiny sliver) rather than one too few - could you send a copy of the data so I can try and reproduce it please? An easy fix might be to simply change the direction of cut - it will perform differently in each direction, so that might resolve it for you! — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#12 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AR6DHVVNBIQ6JHTOUYYLTVTSSUMAHANCNFSM4UHK5WZQ> .

[jonnyhuck]

NB: I have plans to change the process that it uses when it struggles to find a division, so that it better preserves the size/number of divisions