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What is the difference between "Mean Coordinate(s)" and polygon "Centroid" tool available in QGIS?

Taras
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Anil
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    what have you researched so far and what are your findings? – LaughU Aug 07 '18 at 09:03
  • The points obtained after using mean coordinates and polygon centroid for a polygon, do not lie in the same position. I wanted to know the theory behind the result. – Anil Aug 07 '18 at 09:23

1 Answers1

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The polygon centroid is the location where the polygon "balances". If you cut out the shape of a polygon and balanced it on a pencil, that's the centroid.

So the centroid of a square is the centre of the square.

But a square in a GIS could be represented by the four corner points. Or it could be the four corner points plus 1000 points along one side of the square - it would still look the same (square) and have the same centroid, plumb in the middle of the square.

But if you took the average of the coordinate points you'd get a different location. You've now got 1000 points on one side pulling the average way over that side. The mean coordinate would be very near that side, but the centroid is always in the middle.

Spacedman
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