I am using QGIS to do a morphometric analysis of dolines (sinkholes). The dolines have different shapes from circular to elliptical and I need to calculate the major axis of the polygon that represents them. I already use the minimum delimiter box algorithm, which gives me information about the length and width. Now I need to represent the maximum axis inside the polygon and I can not find any method.
Images of minimum bounding box examples taken from Kobal 2015 and Bondensan et al, respectively.