See Region Centroids - Definition and Geometric Planar Properties for an explanation of the terms used here.

The three centroids, principal axis location and principal moments of inertia are used to calculate a best label orientation and centre. This function calculates the geometric centroid and angle.

Tools > SpatialSQL > Region Geometric Propertiesor the  button, calculates the geometric properties of each selected region and directs output to a table of name input_table_rc.

 

A symbol object at an angle paTheta to the x axis is located at the geometric centroid. The geosqlid field is the rowid of the source table and is used to link the properties to your data during labelling. The centroid and angle are sufficient data for input to a labelling application.

Use this function to define an alternative point for labelling and other centroid-related functions.