Where communities thrive


  • Join over 1.5M+ people
  • Join over 100K+ communities
  • Free without limits
  • Create your own community
People
Activity
  • Nov 14 20:49
    letmaik opened #39
  • Oct 25 09:35

    szaghi on master

    update submodules update travis config (compare)

  • Oct 25 09:30

    szaghi on master

    update submodules (compare)

  • Oct 25 09:19

    szaghi on master

    update submodules update travis config (compare)

  • Oct 21 06:34
    rakowsk commented #7
  • Oct 20 16:09
    unfurl-links[bot] commented #7
  • Oct 20 16:09
    rakowsk commented #7
  • Oct 12 17:49
    ShatrovOA commented #38
  • Oct 11 15:25
    szaghi labeled #38
  • Oct 11 15:25
    szaghi assigned #38
  • Oct 11 15:25
    szaghi commented #38
  • Oct 11 13:52
    ShatrovOA edited #38
  • Oct 11 13:44
    ShatrovOA opened #38
  • Sep 19 11:19
    szaghi commented #7
  • Sep 19 11:08

    szaghi on master

    Fix parsing bug issue#7 The me… update travis config Merge branch 'release/0.1.0' (compare)

  • Sep 19 11:06

    szaghi on fix-parsing-bug-issue#7

    (compare)

  • Sep 19 07:54

    szaghi on fix-parsing-bug-issue#7

    (compare)

  • Sep 19 07:52
    szaghi commented #7
  • Sep 19 07:51
    szaghi labeled #7
  • Sep 19 07:51
    szaghi assigned #7
Izaak "Zaak" Beekman
@zbeekman
@/all I'm also looking for a good multiple precision library with similar functionality to GMP including rational arithmetic. Closest I've found in Fortran is http://myweb.lmu.edu/dmsmith/fmlib.html and those listed at http://crd-legacy.lbl.gov/~dhbailey/mpdist/
Stefano Zaghi
@szaghi
@zbeekman I am sorry for the delay, I am really busy. Unfortunately, I have nothing to suggest, my bad. Have you find something yourself?
Izaak "Zaak" Beekman
@zbeekman
For now I am using ISAAC and GMP to match a previous publication. I think XORSHIRO is probably better and for future work I'm still deciding what to do for MP
Stefano Zaghi
@szaghi
Dear /all , have you any Fortran (or Fortran friendly) library for Immersed Boundary simulations to suggest? Toolkits, libraries or the like are much more than welcome. @zbeekman @milancurcic maybe you have done such a simulations? I have to peform a simulation on a very complex geometry where the viscous terms can be neglected, thus I would like to avoid to create a time-consuming Chimera grid this time, IB methods seem to be very suited for this project...
Izaak "Zaak" Beekman
@zbeekman
@/all If you have an opportunity to star, watch and fork the wonderful parallel linear algebra library, PSBLAS and the MultiLevel Domain Decomposition Parallel Preconditioners Package based on PSBLAS (MLD2P4) it would be greatly appreciated. They are pre-requisites for a project I am involved with and I'm trying to get them into Homebrew/Linuxbrew. Both are execellent and very efficient. They are also Fortran based with Modern practices.
@szaghi no good Fortran solutions I know of. https://github.com/cwrowley/ibpm cwrowley was a professor of mine at Princeton though, and is quite a sharp guy. IBAMR is another non-Fortran solution that should be quite good. The only Fortran IB method I know is https://github.com/atchieu/IBFS-IF2D but I have no idea what its quality is.
Stefano Zaghi
@szaghi
@zbeekman Thank you for the insight. By the way, I had already starred PSBLAS, but I was not aware of the Preconditioner library, it is very interesting! Thank you!
Izaak "Zaak" Beekman
@zbeekman
@/all If anyone is going to be at the upcoming SC17 or APS-DFD conferences in Denver CO, please let me know. It would be great to meet up with some of you!
Stefano Zaghi
@szaghi
@zbeekman I do not :cry:
victorsndvg
@victorsndvg
@zbeekman , I will be at SC17 . Let me know the free slots in your agenda and I will try to meet you. I think there is a BoF about Fortran
Rand Huso
@rchuso
I wish I could go to the SC - haven't been to a similar conference since '86. It's too expensive for my New Zealand $. But if anyone is interested, I've put my Fortran MPI + IoC abstraction layer with example program on my web site: http://mjollnir.com/mpiioc/mpiiocFor.html There's a C version and the Python versions there as well. Working on the C++ version now. I'll be giving a talk on this later in 2018 here in NZ at the NeSI conference (no travel budget required.)
Izaak "Zaak" Beekman
@zbeekman
@victorsndvg I will definitely try to make it to the BoF on Fortran
victorsndvg
@victorsndvg
@zbeekman , I saw your photo :smile: . Hope to see you there!
Izaak "Zaak" Beekman
@zbeekman
lol, which photo? twitter probably. I have no idea what you look like. Shoot me an email zbeekman@gmail.com
Stefano Zaghi
@szaghi
@zbeekman Your face is everywhere :smile:
Jacob Williams
@jacobwilliams
@/all FYI I’ll be at AIAA SciTech this week in Kissimmee, FL. Presenting a paper on modern Fortran for spacecraft trajectory optimization. So if any of you are there, stop by and say hello!
Bob Apthorpe
@apthorpe
I got bored this week and took a stab at building a legacy Fortran compatibility library to help people refactor away missing and problematic libraries. Explanation: http://www.acorvid.com/2018/01/20/introducing-the-acorvid-legacy-fortran-compatibility-library/ Project: https://bitbucket.org/apthorpe/alfc It needs a lot of work but it's a start; I'd appreciate feedback & suggestions if anyone wants to take a quick look at it.
boorishpea
@boorishpea
Hi, can anybody tell me why one would declare an unsigned int long
Neil Carlson
@nncarlson
Is anyone here using sphinx/readthedocs for documentation? I'm looking for some Fortran-centric setup and usage pattern examples.
chriselrod
@chriselrod

For such an old language, Fortran really seems to suffer from lack of good resources and mature libraries to help in writing Fortran. Like, I had to wrap a few functions from the R-math libraries (written in C) to get performant probability quantile functions.

I found Fortran For Scientists and Engineers helpful. It's very basic (and has weird things like nested loops in a suboptimal order, but I guess even the lowest optimization levels in a compiler take care of that?), but that makes it a fast read and great for the target audience of scientists/engineers.

You can also google examples of modules. You can save all your code in files, each with a module, and then simple "use [module name]" for the other modules any depend upon. Keeps things organized and will automatically handle interfaces.
Izaak "Zaak" Beekman
@zbeekman
@boorishpea that sounds like a c question, not a Fortran one. But, with twos complement integer arithmetic signed and unsigned integers behave the same way in terms of many but level operations. (I.e. wrap around on overflow, etc.) It is primarily the interpretation of the bit patterns (having a sign bit or not) that distinguishes them. Both can represent the same total number of distinct integers for the same word length. If a signed integer can represent the range (-N, N] then an unsigned integer of the same length can represent [0, 2N). (These ranges likely have some off-by-one errors, I can’t be bothered to look at/workout the exact information.) Unfortunately Fortran has no out of the box support for unsigned integers. So you use unsigned integers when you don’t need negative integers and want to represent larger ones with the same number of bits.
Chris MacMackin
@cmacmackin
Hi all. I have released a new version of FORD with numerous bug fixes, efficiency improvements, and a few new features. Unfortunately some bug still remain, but as I won't be able to work on them for a while and a release was long overdue, I decided to just put out what I currently have.
Sadly, this is likely to be the last, or nearly the last FORD release from me. I have not had time to continue developing it at a reasonable pace over the past few years as I have become busy with other things. If anyone would be interested in taking FORD over as a project, please get in touch with me.
Stefano Zaghi
@szaghi
@cmacmackin Sorry for my long silence, but I am very very busy too... I am sad to read this about FORD, I'll try to follow it as much as possible
@/all I need help: can you link me to some courses/tutorials/guides about a very, very basic Fortran programming material?
Izaak "Zaak" Beekman
@zbeekman
@szaghi oh boy, sounds like you have your work cut out for you. https://www.youtube.com/watch?v=gSJhfnhs598 seems like a decent start... This one is good, but TERRIBLE audio quality: https://www.youtube.com/watch?v=T8xjodqdsIE
Izaak "Zaak" Beekman
@zbeekman
@szaghi one more, this one a document that looks decent: https://www.uv.es/dogarcar/man/IntrFortran90.pdf However, I taught myself from Numerical Recipes in Fortran 77 (https://amzn.to/2zxdwGD) and vol. 2 in Fortran 90 (https://amzn.to/2zk4pJe) and byy reading Metcalf Cohen and Reid "Modern Fortran Explained" https://amzn.to/2zn9Gj2.
@cmacmackin How do you want to transition to community maintenance of FORD? Do you want to give someone else admin access to the FORD repo under your account? Do you want to move the FORD repo to Fortran-FOSS-Programmers org? I'd be happy to help manage the project, and keep it moving forwards. I can't promise much time dedicated to coding, but we're using it on a contract that I am working on currently, so I can (in a way) get paid for trouble shooting/bug fixing/enhancements required by the contract.
Giacomo Rossi
@giacombum
@/all do you have some advice for a book about OpenCL?
Jacob Williams
@jacobwilliams
@cmacmackin I’m also willing to help keep Ford going. I can’t devote much time and I’m not the rockstar Python coder you are but I can pitch in. It’s an awesome tool and your efforts have been greatly appreciated in the poor Fortran community!
Giacomo Rossi
@giacombum
Just to Brother you @/all a little bit more with OpenCL: what do you think about the future of Fortran and accelerators? For example, how CAF could interact with the accelerators? CAF could be directly used on accelerators without any layer in between, or this is not possible? Because I think that, for example, OpenCL is getting more and more attention from hardware developers (because it's open and it can be used on different hardware, that it isn't true for example for CUDA). But when with CUDA Fortran and, for example, PGI compiler is possible to easily parallelize the code to run it on GPU, I think that this is not possible with OpenCL. In other words, you are more inside Fortran community and standard committee: what are your feelings about the future of this language and its interoperability with accelerators and future "de facto" standards?
Stefano Zaghi
@szaghi
@zbeekman Thank you very much for the Fortran materials!
Stefano Zaghi
@szaghi
@giacombum Cuda Fortran is the Evil (IMO). Concerning OpenCL I know very little about it and I never tried to test it, but Francesco should be much more involved, try to ask him about OpenCL performances. CAF in theory is really an "abstract" concept and it should be designed in an agnostic way regarding the hardware, thus I think that at some point it will support some kind of accelerators, but for now, I think that available implementation of CAF are based on an MPI substratum... with its pros and cos. @afanfa and @rouson are really a masters of CAF & Co. and they can illuminate us about CAF exploitation on accelerators. My current approach is to use MPI/CAF and OpenMP, accelerators (NKL, GPU and the like) are far from my radar
Izaak "Zaak" Beekman
@zbeekman
@cmacmackin we could migrate Ford to Fortran-FOSS-Programmers
Giacomo Rossi
@giacombum
dear @afanfa and @rouson , I'm trying to understand if in the future could be possible to use Opencoarrays on accelerators: starting from my very limited knowledge, Opencoarrays are developed over an MPI substratum, that therefore works on almost any x86 and power pc. Do you think that it will be possible to change this substratum in order to move Opencoarrays also to accelerators (in particular, GPU)? Or I'm wrong?
Izaak "Zaak" Beekman
@zbeekman
@giacombum there’s some very antiquated code still in opencoarrays for GPU, however it probably requires GFortran 5 or 6 (maybe even 4.9?) to run. It’s unlikely that we will devote effort to this work unless either a) we receive funding (enough to pay someone qualified to implement it) or b) someone volunteers to implement it. In the short term we are working to support Arm/Flang18 which should help clean up and abstract the code somewhat. That should make porting to GPU less of a burden in the future.
Giacomo Rossi
@giacombum
@zbeekman Thank you for your reply, I completely understand your position: software development is not easy and therefore it can't be always done for free. What I want to know is, however, if Coarrays can be eventually used on accelerators (GPU, frankly speaking) and you answered to this question. Now I've another one: how the offload can be done? And I suppose that the underline layer is not MPI but something other... And are you talking about Opencoarrays or Fortran Coarrays?
Michel Müller
@muellermichel
Hi all. I've been invited to the BCS Fortran Specialist Group meeting in London, and I'm currently sitting there. Will try to plug our group if that's alright ;) http://www.fortran.bcs.org/2018/agenda18.php
they have some of the standards committee members here
victorsndvg
@victorsndvg
Great! :+1:
Michel Müller
@muellermichel
@szaghi regarding CUDA Fortran being evil: could you expand a little bit why you think so? just because it's proprietary / closed source, or is there a deeper reason as well?
Stefano Zaghi
@szaghi
@muellermichel Hi Michel, happy to hear you again (I am sorry for my silence, I am doing very few Fortran in last months...). Yes, essentially because I do not like to chain my self to a closed-proprietary, non standard features. The concept is cool, the implementation could be nice (I do not test is), but the fact that is not a standard rather a proprietary extension let me think that it is not worth to spend my time (which time????) to use it
Michel Müller
@muellermichel
the thing is, I'd rather have one vendor to take GPU support on Fortran seriously and do it with proprietary technology, rather than having no good GPU support at all. During my years of doing GPU on Fortran, CUDA Fortran has been the one thing that's actually stable, performant and with reasonable tooling support.
I generally tend to be more pragmatic with these things. I like to make my work open where possible, but I understand when and why corporations choose to monetize things when they have an edge on the market. The encumbents, like AMD, tend to make their stuff open in order to get a foot in the door, so their motives are far from altruistic either. Personally I hope that AMD with their new successes in x86 can get enough cash to catch up o NVIDIA and build up their source compatible version of "CUDA" - so far I'm not aware of much Fortran support there, but that might change when they see what bigger HPC customers require.
chriselrod
@chriselrod

AMD's ROCm can compile C++ to run the GPU with both g++ and their own hipcc compiler (based on Clang).
Would be great to broader support, and more documentation. Not sure what it would take to add support to more llvm-compiled languages (which would include Flang).

Anyone know anything about BRIG? https://www.phoronix.com/scan.php?page=news_item&px=GCC-9.0-BRIG-Improvements
I can't find anything in the latest (8.2) gcc manual https://gcc.gnu.org/onlinedocs/gcc-8.2.0/gcc/
but perhaps something will come of that.

Giacomo Rossi
@giacombum
I start to look to latest OpenMP standard: it seems very promising because it has some intresting instructions and pragmas for GPU offloading. What do you think about it?
Michel Müller
@muellermichel
Haven't tried OpenMP for GPU yet. I didn't have the best experience with OpenACC either, and so far OpenMP appears to be a poorer version of that to me.
matrixbot
@matrixbot
@astrojuanlu:matrix.org hi all 👋🏽
Ondřej Čertík
@certik
Hi, we have recently open sourced LFortran: https://lfortran.org/, it might be of interest to this group.