Pigasus : Python for IsoGeometric AnalysiS and Unified Simulations.

B-splines and NURBS (Non Uniform Rational B-splines) are widely used in CAD (Computer Aider Design) models. IGA (IsoGeometric Analysis) consists of using these functions to both define the geometry and represent the unknowns that are solution of a Partial Differential Equation, using the Finite Element principle. In this paper we present a new library, namely Πgasus , that was developped in order to bring a common framework between the users (especially physicists) and mathematicians. We want to provide a stable and robust framework, that handles complex geometries and models as it is the case in Plasma Physics. Physicists will be able to use the recent works and results obtained by mathematicians. Πgasus is a 1D, 2D and 3D Fortran code, interfaced with Python. It provides a Geometry module, a FEM (Finite Element Method) computational engine and a Visualization module