Results from FOPI on nuclear collective flow in heavy ion collisions at SIS energies

Directed flow and elliptic flow are studied in heavy ion collisions at SIS energies (100 AMeV-2 AGeV) with the FOPI detector. Several observables related to these flow components are investigated. Recent results obtained from the Fourier expansion method used to describe the anisotropies of the particle azimuthal distributions are presented. An other interesting aspect deals with results concerning the shape parameters of the participant source. Detailed comparisons with the predictions of the IQMD transport model are performed