Groups   224 of 99+      julia-users › Modelling and Simulation using  s MATLAB  s  Julia 8 posts by 4 authors      Michael Fox    4 21 14   There's a MOOC starting tomorrow that promises to teach Modelling and Simulation using MATLAB.  Yes, they did misspell Modeling. The course is being offered by Iversity in partnership with Hochschule RheinMain - University of Applied Sciences in Germany.  I took a similar class 15 years ago and I thought it would be fun to brush up some skills and try doing the course in Julia instead. If anyone else wants in, sign up and let me know. We can have a study group where we road-test Julia. I have no idea what to expect but it sounds like the level is introductory which is fine with me since I expect to spend more time hunting Julia bugs than actual coursework. :   https:  iversity.org c 13?r e3bf1     Jiahao Chen    4 21 14    Modelling  is not a misspelling; it is merely the preferred orthography  for most of the non-US Anglosphere.      joelvan... gmail.com    4 22 14    The description of the course suggests they will make substantial use of Simulink.  Is there anything like that for Julia? Regardless of the blocks-and-wires UI, is there a Julia library that supports dataflow programming for systems with discrete and continuous dynamics?  I'm curious to know the answer, since I have some s w development ideas on this subject...  On Monday, April 21, 2014 7:49:17 AM UTC-7, Michael Fox wrote: There's a MOOC starting tomorrow that promises to teach Modelling and Simulation using MATLAB.  Yes, they did misspell Modeling. The course is being offered by Iversity in partnership with Hochschule RheinMain - University of Applied Sciences in Germany.  I took a similar class 15 years ago and I thought it would be fun to brush up some skills and try doing the course in Julia instead. If anyone else wants in, sign up and let me know. We can have a study group where we road-test Julia. I have no idea what to expect but it sounds like the level is introductory which is fine with me since I expect to spend more time hunting Julia bugs than actual coursework. :   https:  iversity.org c 13?r e3bf1     Michael Fox    4 22 14  Re:  julia-users  Re: Modelling and Simulation using  s MATLAB  s  Julia  This looks promising: https:  github.com BenLauwens SimJulia-jl  But I've learned to be wary of the package list. I would say part of the fun will be coming up with lightweight solutions to replace Matlab's heavyweight solutions. Some simple data-flow framework using coroutines can be developed on the spot if existing packages are found lacking.  --   - Michael     Ivar Nesje    4 22 14  Re:  julia-users  Re: Modelling and Simulation using  s MATLAB  s  Julia  Especially you should be wary of packages that states that the last commit was  authored 11 months ago. It is not necessarily a sign of bad quality, but you might find out that the author is not available to help debug errors, and you might not even get your Pull Requests reviewed and merged. The issue tracker is also a nice place to look for activity, and it has a 9 months old  apparent  typo that has not yet been fixed. There has been lots of deprecations since May last year, so I would recommend that you try using 0.2, because many deprecation warnings have been removed in the latest master.  The good news is that the licence allows you to create a fork and then your fixed package can be registred in METADATA instead.      Joel VanderWerf    4 22 14  Re:  julia-users  Re: Modelling and Simulation using  s MATLAB  s  Julia   Ivar,   Where do I find the 0.2 version you mention? The github master seems to  be at 0.1.3: https:  github.com BenLauwens SimJulia-jl blob master VERSION.   On 04 22 2014 12:24 PM, Ivar Nesje wrote:    Especially you should be wary of packages that states that the last    commit was  authored 11 months ago. It is not necessarily a sign of bad    quality, but you might find out that the author is not available to help    debug errors, and you might not even get your Pull Requests reviewed and    merged. The issue tracker is also a nice place to look for activity, and    it has a 9 months old     https:  github.com BenLauwens SimJulia-jl issues 8   apparent  typo    that has not yet been fixed. There has been lots of deprecations since    May last year, so I would recommend that you try using 0.2, because many    deprecation warnings have been removed in the latest master.       The good news is that the licence allows you to create a fork and then    your fixed package can be registred in METADATA instead.          kl. 20:49:15 UTC+2 tirsdag 22. april 2014 skrev Michael Fox følgende:           This looks promising: https:  github.com BenLauwens SimJulia-jl         https:  github.com BenLauwens SimJulia-jl            But I've learned to be wary of the package list. I would say part of        the fun will be coming up with lightweight solutions to replace        Matlab's heavyweight solutions. Some simple data-flow framework        using coroutines can be developed on the spot if existing packages        are found lacking.              On Tue, Apr 22, 2014 at 9:59 AM,  joelvan... gmail.com         javascript:   wrote:                  The description of the course suggests they will make            substantial use of Simulink.               Is there anything like that for Julia? Regardless of the            blocks-and-wires UI, is there a Julia library that supports            dataflow programming for systems with discrete and            continuous dynamics?               I'm curious to know the answer, since I have some s w            development ideas on this subject...               On Monday, April 21, 2014 7:49:17 AM UTC-7, Michael Fox wrote:                   There's a MOOC starting tomorrow that promises to teach                Modelling and Simulation using MATLAB.  Yes, they did                misspell Modeling. The course is being offered by Iversity                in partnership with Hochschule RheinMain - University of                Applied Sciences in Germany.  I took a similar class 15                years ago and I thought it would be fun to brush up some                skills and try doing the course in Julia instead. If anyone                else wants in, sign up and let me know. We can have a study                group where we road-test Julia. I have no idea what to                expect but it sounds like the level is introductory which is                fine with me since I expect to spend more time hunting Julia                bugs than actual coursework. :                    https:  iversity.org c 13?r __e3bf1       Ivar Nesje    4 22 14  Re:  julia-users  Re: Modelling and Simulation using  s MATLAB  s  Julia  I ment Julia version 0.2, I have not looked at SimJulia versions.  Ivar      Joel VanderWerf    4 22 14  Re:  julia-users  Re: Modelling and Simulation using  s MATLAB  s  Julia   Michael,   Thanks for the SimJulia link. Some good ideas in there, but also some  things missing.  Algebraic equations? State transitions?    Be wary of  lightweight  solutions. They may have naive semantics,  inherited from the operational semantics of the programming language  they are written in. There are many issues in hybrid   discrete+continuous  simulation that need to be thought out carefully.   For example, what is the order of execution during a parallel update of  the discrete states in multiple components? Is this order a source of  non-determinism in the outcome of the simulation?   Suppose that the dataflow topology  i.e. the  wires   can change  dynamically  it can't in Simulink, but you need this for mobile agent  simulations . Then what is the semantics of those updates relative to  guard checks and updates of other discrete state vars?   How  and when  does a state transition impact the value of a variable  that has been defined by an algebraic equation, if the new state imposes  a new equation?   These questions are really easy to skip over if the concurrency model is  just inherited from the programming language's own model, whether  thread, coroutine, task, fiber, process. A specialized concurrency  model, using fine-grained phases within each discrete step, may be  necessary to coordinate execution without giving up determinism.   And there are issues around the continuous dataflow abstraction itself.  How does internal integrator state  intermediate step values  interact  with non-integration functions? The last time I looked at Simulink   maybe 2009 , this state was not preserved across delay blocks, so  integrator and delay blocks do not commute without some loss of accuracy.   Returning to Julia and simulation... I'm interested in implementing a  simulation engine for dynamic networks of hybrid automata. I've worked  on this before in Clanguage 1  and Ruby+C 2 , but Julia now seems to be exactly  the right language for this kind of framework.   Btw, I'll be at the SF Julia meetup tonight 3 . If anyone wants to talk,  come find me!    1  http:  gateway.path.berkeley.edu SHIFT publications.html  very old  papers     2  https:  github.com vjoel redshift  ongoing work ,  http:  confreaks.com videos 165-rubyconf2009-dsls-code-generation-and-new-domains-for-ruby    3  http:  www.meetup.com Bay-Area-Julia-Users events 164510912   On 04 22 2014 11:49 AM, Michael Fox wrote:    This looks promising: https:  github.com BenLauwens SimJulia-jl       But I've learned to be wary of the package list. I would say part of the    fun will be coming up with lightweight solutions to replace Matlab's    heavyweight solutions. Some simple data-flow framework using coroutines    can be developed on the spot if existing packages are found lacking.          On Tue, Apr 22, 2014 at 9:59 AM,  joelvan... gmail.com     mailto:joelvan... gmail.com   wrote:              The description of the course suggests they will make substantial        use of Simulink.           Is there anything like that for Julia? Regardless of the        blocks-and-wires UI, is there a Julia library that supports dataflow        programming for systems with discrete and continuous dynamics?           I'm curious to know the answer, since I have some s w development        ideas on this subject...           On Monday, April 21, 2014 7:49:17 AM UTC-7, Michael Fox wrote:               There's a MOOC starting tomorrow that promises to teach            Modelling and Simulation using MATLAB.  Yes, they did misspell            Modeling. The course is being offered by Iversity in partnership            with Hochschule RheinMain - University of Applied Sciences in            Germany.  I took a similar class 15 years ago and I thought it            would be fun to brush up some skills and try doing the course in            Julia instead. If anyone else wants in, sign up and let me know.            We can have a study group where we road-test Julia. I have no            idea what to expect but it sounds like the level is introductory            which is fine with me since I expect to spend more time hunting            Julia bugs than actual coursework. :                https:  iversity.org c 13?r __e3bf1