(sec-pythonutilityfunctions)= # Python Utility Functions This chapter describes in every section the functions and classes of the utility modules. These modules help to create multibody systems with the Exudyn core module. Functions are implemented in Python and can be changed, extended and verified by the user - **check the source code** by entering a function in Spyder and pressing **CTRL + left mouse button**. These Python functions are much slower than the functions of the C++ core; some matrix computations with larger matrices, implemented in numpy and scipy, are parallelised and therefore very efficient. Note that in general functions accept lists and numpy arrays. If not, an error will occur, which is easily tracked. Furthermore, angles are generally provided in radian ($2\pi$ equals $360\,^o$) and no units are used for distances, but it is recommended to use SI units (m, kg, s) throughout. Functions have been implemented, if not otherwise mentioned, by Johannes Gerstmayr. ```{toctree} :maxdepth: 2 advancedUtilities artificialIntelligence basicUtilities beams demos FEM graphics graphicsDataUtilities misc.GUI misc.settingsUtilities interactive kinematicTree lieGroupBasics misc.mainSystemExtensions particles physics plot processing rigidBodyUtilities robotics robotics.rosInterface robotics.future robotics.models robotics.mobile robotics.motion robotics.special robotics.utilities shells signalProcessing solver utilities ```