With great pleasure we announce the availability of SimPy version 1.9. This is a major release, with significant changes to API and documentation, bug fixes, and improved performance for large models.
SimPy 1.9 can be downloaded from http://sourceforge.net/project/showfiles.php?group_id=62366 . The SimPy homepage is at http://SimPy.SourceForge.Net . What is SimPy? ============== SimPy (= Simulation in Python) is an object-oriented, process-based discrete-event simulation language completely implemented in Python. It is released under the GNU Lesser GPL (LGPL). SimPy provides the modeler with components of a simulation model including processes, for active components like customers, messages, and vehicles, and resources, for passive components that form limited capacity congestion points like servers, checkout counters, and tunnels. It also provides monitor variables to aid in gathering statistics. Random variates are provided by the standard Python random module. Many users claim that SimPy is one of the cleanest, easiest to use discrete event simulation packages! SimPy is in use at many universities, research institutes and in industry. SimPy comes with data collection capabilities, GUI and plotting packages. It can be easily interfaced to other packages, such as plotting, statistics, or database systems. SimPy is platform-independent and runs on all systems on which Python 2.3 or later is available. Acknowledgements ================ This version is again the result of many months of intense collaboration in the SimPy community. It includes design ideas and improvements of runtime performance through better event list handling proposed by Prof. Norm Matloff and a team of graduate students working with him. Thank you, guys! We also wish to thank all users and developers who assisted in performance measurement and beta testing. Our thanks go also to Virgil Stokes of Uppsala University who proposed the addition of a method in Monitor and Tally which returns the time-weighted variance of observations. ============================= Release notes for SimPy 1.9 ============================= Changes ========= - The handling of the event list has been changed to provide significantly shorter runtimes for larger models (models with thousands of processes) and models with many interrupts or process cancellations. The event list is now only partially sorted, using the ``heapq`` package instead of bisect. Cancelled event notices are no longer removed by unpost, but just marked and then popped and ignored by nextev. The event list is no longer based on a dictionary. This latter, very important improvement is based on a SimPy tuning study by Prof. Norm Matloff and some of his bright students. Thanks, Norm and team! - The Manual has been edited and given an easier-to-read layout. - The Bank2 tutorial has been extended. Repairs ======== - The tracing of "activate" statements by SimulationTrace.py (which had been erroneously de-activated) has been enabled again. Additions ============ - A method returning the time-weighted variance of observations has been added to classes Monitor and Tally. - A shortcut activation method called "start" has been added to class Process. ------------------------------------------------------------------------ (end of Release Notes) Enjoy! Best wishes for happy, productive SimPying in 2008! Tony Vignaux Klaus Müller -- http://mail.python.org/mailman/listinfo/python-announce-list Support the Python Software Foundation: http://www.python.org/psf/donations.html
