Hi Andrew, On Saturday, April 2, 2016 at 7:10:00 PM UTC+2, Andrew Keller wrote: > > Regarding your first question posed in this thread, I think you might be > interested in this documentation > <http://docs.julialang.org/en/latest/devdocs/functions/> of how functions > will work in Julia 0.5 if you haven't read it already. >
Yes, I'm aware that some big changes are coming with 0.5, and many of them (e.g. threads and fast anonymous functions) are of course highly relevant to this kind of application. For now I'm kinda stuck with 0.4 for actual use cases, because so many packages (e.g. PyPlot, Gadfly, ...) have trouble with 0.5 at the moment. But once 0.5 is ready, I will probably not even try to keep things compatible with 0.4, as this is a new project anyway. I hope you don't mind that I've tried out your setindex and getindex > approach. [...] It is very pleasant to use but I have not benchmarked it in > any serious way [...] If you'd like me to try out something I'll see what I > can do. > Thanks, you're more than welcome! The more the merrier, and this can only profit from wide testing. It would be good to try how this performs with, say, about 500 feature types and 500 device types, each implementing like 100 features. I hope this will still perform well in dynamic dispatch situations - maybe one of the Julia experts can weigh in here? It sounds like you have probably been thinking deeply about instrument > control for a much longer period of time than I have. > Well, thinking and learning a lot from my earlier mistakes. :-) You can find any number of discussion threads, GitHub issues, etc. on > traits in Julia but I don't know what current consensus is. > I did play with some of the current approaches to traits in Julia a while ago (Mauro's and Tim's work), and it's definitely something to watch (I'd love to see something like that in Base some day). For now, I hope we may be able to get by without explicit "device classes". > Thanks for linking to your code. I have no experience with Scala but I > will take a look at it. > Don't judge to harshly. :-) This has been a work in progress for many years, and it is in active use for two long-term physics experiments and multiple lab applications - but since it was always driven by our current needs, I often didn't find time to port new ideas and concepts to older portions of the code. One of the goals was always to use it for both high-rate physics DAQ, and low-rate "slow-control"/SCADA applications. I was planning a major overhaul, but recently decided that Julia will be a better platform in the long run for various reasons (one of them that most students don't have time to learn several programming languages, and Scala isn't really an option for our kind of data analysis). Implementing specific devices has actually only been a fraction of the work - a large part has always been implementing communication protocols. For various devices, I needed (and implemented) VXI11, Modbus, SNMP, VME (over ethernet bridge), CANOpen (for one speficic gateway), and various vendor specific ASCII and binary protocols (e.g. Pfeiffer vaccum, old Keithley ASCII, etc.). Plus things like an SCPI parser, etc.. I look forward to port all of that to Julia - well, eventually ... ;-) I'd like the core to stay pure-Julia, though this will be challenging with VXI11 and SNMP, as there's no native-Julia ONC-RPC or SNMP library. And for devices that really need a vendor-specific VISA driver (because SCPI over VXI11 is not enough) Instruments.jl (https://github.com/BBN-Q/Instruments.jl) may come in play (haven't tried it yet). I'd love to work with other people interested in this - Julia is great at making data analysis fast and easy, not reason it shouldn't be as great at taking the data in the first place! > Unitful.jl and SIUnits.jl globally have the same approach [...] My package > only supports Julia 0.5 though. [...]An open question is how one could > dispatch on the dimensions (e.g. x::Length). > Ah, right, now I remember - i kinda mixed up SIUnits and Unitful, sorry. I did give Unitful a quick try when you announced it on the list, and I was very impressed. But then I kinda had to force myself to put it aside for a while, since I can't really switch to 0.5 yet. ;-) I do recall the discussion about dispatching on units, though - that would be way cool, but even without, Unitful will be a great ingredient to any Julia data acquisition solution. Cheers, Oliver
