Paper: Enhancing SfePy with Isogeometric Analysis (Robert Cimrman)

Hi! Here it is...
This is much too short a description for IGA. Let's take the whole domain of Fig. 1 as a single patch - whatever patch means in IGA. How does IGA define a basis for this patch? And what is that "knot vector"? Fig. 6 provides a nice illustration of an IGA basis (or perhaps /the/ IGA basis? Is the basis unique?), but no hint at how it is obtained.