Convert Position Vectors to Vertices, and Vice Versa!

A utility function to convert between rectangular position [x y w h] and vertices [x; y]

Many MATLAB and Toolbox functions require the specification of rectangular regions. Several use "position vectors," specified as [Xmin Ymin Width Height], many others require specification by vertex, [x; y]. For rectangular ROIs, either one defines the other. This submission facilitates easy conversion from position to vertex:
verts = posToVert(posn);
or from vertices to position:

posn = vertToPos(vert);

Simple, but useful.