I have attached a file containing a vector of 11 polyshape objects
>> whos pgon
Name Size Bytes Class Attributes
pgon 1x11 3080 polyshape
When these polyshapes are plotted, they form an agglomeration of triangles which, to the eye at least, has 2 holes
However, when I plot the union of this polyshape vector, a 3rd hole forms (this is in R2018a). It defies my intuition that taking the union of a collection of polygons could introduce more holes. Can anyone think why this might occur?