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Exudyn
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These are the access functions to the Exudyn module. General usage is explained in Section :ref:`sec-generalpythoninterface`\  and examples are provided there. The C++ module \ ``exudyn``\  is the root level object linked between Python and C++.In the installed site-packages, the according file is usually denoted as \ ``exudynCPP.pyd``\  for the regular module, \ ``exudynCPPfast.pyd``\  for the module without range checks and \ ``exudynCPPnoAVX.pyd``\  for the module compiled without AVX vector extensions (may depend on your installation).

.. code-block:: python
   :linenos:
   
   #import exudyn module:
   import exudyn as exu
   #create systemcontainer and mbs:
   SC = exu.SystemContainer()
   mbs = SC.AddSystem()

\ The class **exudyn** has the following **functions and structures**:

* | **Help**\ (): 
  | Show basic help information
* | **RequireVersion**\ (\ *requiredVersionString*\ ): 
  | Checks if the installed version is according to the required version. Major, micro and minor version must agree the required level. This function is defined in the \ ``__init__.py``\  file
  | *Example*:

  .. code-block:: python

     exu.RequireVersion("1.0.31")

* | **SetWriteToFile**\ (\ *filename*\ , \ *flagWriteToFile*\  = True, \ *flagAppend*\  = False, \ *flagFlushAlways*\  = False): 
  | set flag to write (True) or not write to console; default value of flagWriteToFile = False; flagAppend appends output to file, if set True; in order to finalize the file, write \ ``exu.SetWriteToFile('', False)``\  to close the output file; in case of flagFlushAlways=True, file will be finalized immediately in every print command, but may be slower;
  | *Example*:

  .. code-block:: python

     exudyn.config.printToConsole = False #no output to console
     exu.SetWriteToFile(filename='testOutput.log', flagWriteToFile=True, flagAppend=False, flagFlushAlways=False)
     exu.Print('print this to file')
     exu.SetWriteToFile('', False) #terminate writing to file which closes the file

* | **Print**\ (): 
  | this allows printing via exudyn with similar syntax as in Python print(args) except for keyword arguments: exu.Print('test=',42,sep=' ',end='',flush=True); allows to redirect all output to file given by SetWriteToFile(...); does not print to console in case that exudyn.config.printToConsole eis set to False
* | **InvalidIndex**\ (): 
  | This function provides the invalid index, which may depend on the kind of 32-bit, 64-bit signed or unsigned integer; e.g. node index or item index in list; currently, the InvalidIndex() gives -1, but it may be changed in future versions, therefore you should use this function
* | **\_\_version\_\_**:
  | contains the current version of the Exudyn package
* | **symbolic**:
  | the symbolic submodule for creating symbolic variables in Python, see documentation of Symbolic; For details, see Section Symbolic.
* | **config**:
  | global config settings, like precision, print behavior, warnings, etc.
* | **config.suppressWarnings**:
  | flag to suppress all warnings (default=False)
* | **config.outputPrecision**:
  | change precision (number of digits) in C++ and Python output
* | **config.linalgOutputFormatPython**:
  | True (default): use Python format for output of vectors and matrices; False: use Matlab format
* | **config.printDelayMilliSeconds**:
  | add some delay (in milliSeconds) to printing to console (exudyn.Print), in order to let console (e.g. Spyder) process the output; default = 0
* | **config.printFlushAlways**:
  | flush always buffers when using exudyn.Print(...) to write to file or console; this is needed if you are streaming text or showing counters in parameter variation; default=False
* | **config.printToConsole**:
  | enables or disables writing to console with exudyn.Print(...); default=True
* | **config.printToFile**:
  | flag that shows if writing to file with exudyn.Print(...) is enabled; flag is readonly
* | **config.printFileName**:
  | file name for writing to file with exudyn.Print(...); flag is readonly
* | **config.printToFileAppend**:
  | flag that shows if append mode is used for writing to file with exudyn.Print(...); flag is readonly
* | **config.Version**\ (\ *addDetails*\  = False): 
  | Get Exudyn built version as string (if addDetails=True, adds more information on compilation Python version, platform, etc.; the Python micro version may differ from that you are working with; AVX2 shows that you are running a AVX2 compiled version)
* | **experimental**:
  | Experimental features, not intended for regular users; for available features, see the C++ code class PyExperimental
* | **special**:
  | special attributes and functions, such as global (solver) flags or helper functions; not intended for regular users; for available features, see the C++ code class PySpecial
* | **special.InfoStat**\ (\ *writeOutput*\  = True): 
  | Retrieve list of global information on memory allocation and other counts as list:[array_new_counts, array_delete_counts, vector_new_counts, vector_delete_counts, matrix_new_counts, matrix_delete_counts, linkedDataVectorCast_counts]; May be extended in future; if writeOutput==True, it additionally prints the statistics; counts for new vectors and matrices should not depend on numberOfSteps, except for some objects such as ObjectGenericODE2 and for (sensor) output to files; Not available if code is compiled with __FAST_EXUDYN_LINALG flag
* | **special.solver**:
  | special solver attributes and functions; not intended for regular users; for available features, see the C++ code class PySpecialSolver
* | **special.solver.timeout**:
  | if >= 0, the solver stops after reaching accoring CPU time specified with timeout; makes sense for parameter variation, automatic testing or for long-running simulations; default=-1 (no timeout)
* | **special.solver.multiThreadingLoadBalancing**:
  | if True (=default), multithreaded code parts (in particular solver and raytracing) use load balancing, which may give better performance in case of non-equilibrated loads; (mobile) Intel CPUs may perform significantly better without load balancing
* | **variables**:
  | this dictionary may be used by the user to store exudyn-wide data in order to avoid global Python variables; usage: exu.variables["myvar"] = 42; can be used in particular to exchange data between different mbs or between packages by importing exudyn.variables wherever needed.
* | **sys**:
  | this dictionary is used and reserved by the system, e.g. for testsuite, graphics or system function to store module-wide data in order to avoid global Python variables; the variable exu.sys['renderState'] contains the last render state after SC.renderer.Stop() and can be used for subsequent simulations