-- card: 4070 from stack: in -- bmap block id: 5655 -- flags: 0000 -- background id: 2623 -- name: -- part contents for background part 22 ----- text ----- A Poincare section is a fundamental tool to picture and understand chaos. • It is any particular cross-section through the attractor; and thus is of one dimension less than the state space. The 3-D model systems which we will explore thus have a 2-D Poincare section which can be pictured.