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I am interested to know how the Point on surface tool works in QGIS 3. I am choosing to use this rather than the Centroids tool which works of the "center of mass" methodology because this creates a point outside the area of the polygon which is not suitable for my needs.

The QGIS documentation does not seem to explain the calculation used but I would like to know so I can test whether it is suitable for my analysis and so I can incorporate an error with my calculations.

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    It's an open source tool, so you just need to start digging. Most labeling points are calculated from the midpoint of a transect, so some clever test cases can often locate the transfers. – Vince Jun 13 '19 at 10:04
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    check this excellent (empirical) answer – geozelot Jun 13 '19 at 10:06
  • Both the linked answer with its comment (PostGIS) and this post (QGIS) are relying on GEOS, so it is the same algorithm. – JGH Jun 13 '19 at 11:29