[julia-users] Re: Julia code 5x to 30x slower than Matlab code

sexta-feira, 25 de Setembro de 2015 às 14:47:49 UTC+1, Marcio Sales escreveu: > > all right... Well.. Julia's price will allways be better... > Btw.. what about crowdfunded initiatives? Has anyone tried that? I would > be wiling to donate for a geospatial visualization package, for example...

[julia-users] Julia equivalent to a static member function in C++/MATLAB

Hi, In C++ or in MATLAB I would use static member functions to keep the constructors nice and simple, e.g. class MyMatrix { public: static MyMatrix zeros(int n, int m); static MyMatrix ones(int n, int m); static MyMatrix eye(int n); ... }; Which allows me to create class instances

[julia-users] Re: help!

Thanks!

[julia-users] Re: Julia equivalent to a static member function in C++/MATLAB

On Friday, September 25, 2015 at 11:56:46 AM UTC-4, Joel Andersson wrote: > > Hi, > > In C++ or in MATLAB I would use static member functions to keep the > constructors nice and simple, e.g. > class MyMatrix { > public: > static MyMatrix zeros(int n, int m); > static MyMatrix ones(int n,

Re: [julia-users] FFTW.REDFT00 and FFT.RODFT00 are ~10x slower than other routines?

On Wednesday, September 23, 2015 at 9:07:51 PM UTC-4, Sheehan Olver wrote: > > OK that makes sense. But then why is rfft on a vector length 2*(n-1) more > than 2x faster than FFT.REDFT00? > > *julia> **r=rand(10);@time for k=1:100 FFTW.r2r(r,FFTW.REDFT00) end;* > 2.496130 seconds (8.30 k

[julia-users] Re: Julia code 5x to 30x slower than Matlab code

This just came to while I remembered that Matlab is so expensive.. I never did this myself, but heard that Openstreetmaps, for example, was/is crowdsourced, so why not trying it for Julia development?

Re: [julia-users] Re: What are the "strengths" of the Julia "ecosystem" (e.g. for bio and quants/finance)? This is not a very specific question (while sub-questions are), you've been warned..

> From browsing issues, it looks like the HttpServer.jl performance issue > you referenced below should be now fixed by > https://github.com/JuliaWeb/HttpServer.jl/pull/59. Yes, this issue has been fixed. It seems Julia can have low latency Yes, on my later tests latency was pretty

[julia-users] Re: Crowdsourced Julia development

$5 to the first person to take transposes seriously https://www.bountysource.com/issues/1333116-taking-vector-transposes-seriously/backers On Friday, September 25, 2015 at 10:45:30 AM UTC-4, Tom Breloff wrote: > > Moving the discussion from the matlab thread... > > The idea was brought up about

[julia-users] Crowdsourced Julia development

Moving the discussion from the matlab thread... The idea was brought up about being able to contribute money to package development to motivate developers... a quick search brought up this: https://www.bountysource.com/ Does anyone have any experience with this? Are there other similar

[julia-users] Re: help!

You can also use julia> @doc sin sin(x) Compute sine of x, where x is in radians

[julia-users] Why two based indexing? [A package.. it's not the default..]

https://libraries.io/julia/TwoBasedIndexing http://python-history.blogspot.is/2013/10/why-python-uses-0-based-indexing.html [While Guido's former ABC used 1-based] "Guido van RossumOctober 24, 2013 at 8:49 AM To anyone who prefers 1-based indexing: you are the same people who screwed up the

[julia-users] Re: Julia equivalent to a static member function in C++/MATLAB

> In Julia, you can do the same thing, it is just spelled differently. You > could do x = zeros(MyMatrix, 3, 4) where you have defined Base.zeros(::Type{MyMatrix}, m, n) = . Show trimmed content Of course in Julia you can do anything you want. However, is it recommended to

[julia-users] Re: Pkg.[update()/install()/build()] woes on Windows 10 64 bit

Try deleting everything in C:\Users\ejfie\.julia\v0.3\.cache - something might be corrupt there On Friday, September 25, 2015 at 12:29:14 PM UTC-7, Evan Fields wrote: > > I've been encountering problems with packages. Here's what happened: > >- I installed Julia 0.3.11 via the 64 bit .exe

[julia-users] Is there a tutorial on how to set up my own Julia cluster?

Hello everyone! I am trying to set up a Julia cluster with 20 nodes, this is the very first time I've tried something like this. I have looked around for examples, but documentation is not very helpful for me: *Julia can be started in parallel mode with either the -p or the --machinefile

[julia-users] Re: Optimal Control using Dynamic Programming

I'm also bias to recommend formulating a nonlinear programming problem and using JuMP with IPOPT. This approach has been successfully demonstrated in the chemical engineering controls/systems literature on some rather nasty large nonlinear systems. Here is a sample problem for nonlinear

[julia-users] Large HDF5 matrix multiplication

I have a very large, dense matrix (too large to fit in RAM) "A" saved in an HDF5/JLD file. I also have several vectors of the same dimension v[1]..v[n], which *are* able to fit in memory, and I would like to know the result of multiplying each vector by my matrix A. My current idea is to do this

[julia-users] Re: Large HDF5 matrix multiplication

What you are asking for is called an "out of core" matrix-multiplication algorithm. If you google for it, you'll find several papers on this. The key (as is also true for in-memory matrix operations), is to maximize memory locality. However, there doesn't seem to be much free code available

Re: [julia-users] Re: Crowdsourced Julia development

I don't know, if I made the right conclusion, but it looks like this guy made 27 k$ in a month: https://www.bountysource.com/people/34958-arigo On Friday, September 25, 2015 at 7:55:16 PM UTC+3, Stefan Karpinski wrote: > > Is anyone aware of success stories from open source bounties? Or bad >

[julia-users] Pkg.[update()/install()/build()] woes on Windows 10 64 bit

I've been encountering problems with packages. Here's what happened: - I installed Julia 0.3.11 via the 64 bit .exe on julialang.org - Changed the install path to C:\Julia-0.3.11 but otherwise all default options - On Windows 10 x64, not using Cygwin or related - Right after

[julia-users] Re: Emacs, ESS and julia-mode

For what it's worth, my pull request to ESS to add support for using '?' in the Julia REPL for documentation lookup was merged into master earlier this week, so if you update, that should work now! The docstring comes up in a new help buffer (like ESS's R REPL) rather than just being printed

[julia-users] Re: Same native code, different performance

Out of curiosity, I tried the following one (on julia 0.4-rc1) f(x) = ( c = cos(x); c^3 ) f_float(x) = ( c = cos(x); c^3.0 ) then I get 0.006489 seconds 0.013220 seconds but with the original code, I get 0.076714 seconds 0.013280 seconds (both without @fastmath)

Re: [julia-users] Re: Optimal Control using Dynamic Programming

If you want an uninitialized 61-by-61 array of double precision floating point numbers you can do Array(61, 61) If you want the array initialized to zero you can call zeros(61, 61) A few for loops should accomplish what you're after here. Depending how expenaive your cost function is to

Re: [julia-users] Re: Optimal Control using Dynamic Programming

I have 3 states and two inputs. State 1 is [10:1:20], state 2 is [85:0.2:95] and state 3 is [1:1:12]. The two inputs are [0 1] and [-1 0]. On Sep 25, 2015 1:00 PM, "Tony Kelman" wrote: > If you want an uninitialized 61-by-61 array of double precision floating > point numbers you

Re: [julia-users] Stateflow equivalent in Julia

It's not too clear to me what's trying to be accomplished here, but "gear" and "N" are optimization variables and can't be used inside conditional statements. You can use getValue() to query the value of the variables in an optimal solution after calling solve(). If these statements are

[julia-users] Re: Crowdsourced Julia development

I just created a bounty for implementing a low latency garbage collector: https://www.bountysource.com/issues/5020251-implement-a-low-latency-incremental-garbage-collector Uwe Am Freitag, 25. September 2015 17:31:11 UTC+2 schrieb Jonathan Malmaud: > > $5 to the first person to take transposes

Re: [julia-users] Re: Crowdsourced Julia development

Is anyone aware of success stories from open source bounties? Or bad stories for that matter? On Fri, Sep 25, 2015 at 12:35 PM, Uwe Fechner wrote: > I just created a bounty for implementing a low latency garbage collector: > >

[julia-users] Re: Optimal Control using Dynamic Programming

you may find the Julia interface to apmonitor useful: https://groups.google.com/forum/#!searchin/julia-opt/apmonitor/julia-opt/y5sc_xtLJfk/PKNBik_A82AJ good luck, cdm On Thursday, September 24, 2015 at 10:25:19 PM UTC-7, NV wrote: > > Hi, > I am new to Julia. I need to solve an optimal

Re: [julia-users] Large HDF5 matrix multiplication

Some background information about HDF5 and chunking: HDF5 supports chunking of datasets. If you look at an HDF5 file via h5ls or h5dump, you should see the chunk size. "Chunking" means that the data are not stored contiguously, but in terms of chunks with a certain size (e.g. 100x100 elements);

Re: [julia-users] Re: Pkg.[update()/install()/build()] woes on Windows 10 64 bit

What is it? A cache. Other than that, no idea what it accomplishes (aside from reading the code to find out) or why it works the way it does. It was added in https://github.com/JuliaLang/julia/commit/df7a08893e4402182ec64178ffdb3130aa228943 but there are no design docs on the package

RE: [julia-users] Re: Pkg.[update()/install()/build()] woes on Windows 10 64 bit

What is the .cache directory actually? And why is it moved into the ~\.julia folder for 0.4? From: julia-users@googlegroups.com [mailto:julia-users@googlegroups.com] On Behalf Of Tony Kelman Sent: Friday, September 25, 2015 2:35 PM To: julia-users Subject:

RE: [julia-users] Re: Pkg.[update()/install()/build()] woes on Windows 10 64 bit

Stefan, any pointers about this design? I sometimes delete the folder of a package and then reinstall it with Pkg.update() if something got screwed up. Do I have to manually manage what is going on in .cache in that case as well? Thanks, David From: julia-users@googlegroups.com

Re: [julia-users] Is there a tutorial on how to set up my own Julia cluster?

Hi Ismael, So I don’t actually know anything about setting up a Julia cluster specifically, but it sounds like you do indeed need to have an SSH server set up on each machine. That’s actually not very uncommon on linux boxes and it’s very possible there’s already one running by default. One

[julia-users] Re: Julia equivalent to a static member function in C++/MATLAB

You probably know this, but the way dispatch works in Julia, it will look for a function matching the signatures. Since, presumably, MyMatrix is not in base Julia, that zeros function will do whatever you want it to do because you have yo implement it.

[julia-users] How to import all symbols from a module with @everywhere?

Hello everyone! I have been trying to do some parallel tests with a simple example using Images and Colors, you can see here: - http://nbviewer.ipython.org/gist/Ismael-VC/e18bcae78a49f68a0838 ERROR (unhandled task failure): On worker 15: UndefVarError: Gray not defined The same on every

Re: [julia-users] Re: Request for comments: best way to deal with type uncertainty.

Le jeudi 24 septembre 2015 à 17:41 -0700, Ben Ward a écrit : > As an update: We have tested fetching annotations without trying to > enforce type, and then another in which we don't. I don't understand > why, but the one in which we don't enforce type, is faster, it is > also puzzling for me as

[julia-users] Re: How to find connected components in a matrix using Julia

Hej Charles, in the future please only post in one place. A lot of the people who answer on SO are also here. You can use the label_components function in Images.jl https://github.com/timholy/Images.jl/blob/master/doc/function_reference.md#label_components To get the the list of coordinates

Re: [julia-users] Re: Julia code 5x to 30x slower than Matlab code

+1 Someone give this man a cookie. On 25 September 2015 at 01:46, Steven G. Johnson wrote: > To put it another way, there are plenty of problems that can't be > vectorized effectively. ODEs, matrix assembly for FEM or BEM, implementing > special functions... If you do

[julia-users] Re: Optimal Control using Dynamic Programming

Hello, as far as I know, there is no ready-made package for optimal control. There is one package on control design: https://github.com/JuliaControl/Control.jl And there are a lot of packages for solving optimization problems. Could you be a little bit more specific about your problem? How do

Re: [julia-users] Is there a way to define abstract type from a type in base.jl

Julia's parametric types are invariant (except tuples). To figure out what that means have a read through http://docs.julialang.org/en/release-0.4/manual/types/#parametric-composite-types > How to make Array{BigFloat,1}<:Array{Real,1}? This is always false (that is invariance). But presumably

[julia-users] Can't install Cairo, Winston, IJulia... on OSX

Hi folks, I start to learn how painful thinks can get when you miss different things from different packages... I feel somehow miserable. I try to install Winston, which needs Cairo, etc... on my OSX Yosemite box. When I issue Pkg.add("Winston") for exemple I get the following: INFO:

[julia-users] Re: Can't install Cairo, Winston, IJulia... on OSX

This is a strange error, closest thing I can find is https://github.com/JuliaLang/julia/issues/10434. Could you test with the 0.4.0-rc2 version of Julia that's available on the downloads page? On Friday, September 25, 2015 at 12:52:23 AM UTC-7, Ferran Mazzanti wrote: > > Hi folks, > I start to

[julia-users] Re: Julia code 5x to 30x slower than Matlab code

Although not understanding the final part of the performance tips, I would like to make the point here that the "style guide" could also use some love. I am too obsessive to aesthetic. I cannot accept to write ugly code. On Thursday, September 24, 2015 at 10:13:18 PM UTC+2, Steven G.

Re: [julia-users] Re: How to find connected components in a matrix using Julia

Hi Valentin, Thanks a lot for your suggestion! It makes exactly what I need, with a clear code. I still don't know if efficiency will be an issue for my problems, but I hope it won't. Just don't agree with your advice to only post in one place. Is there any special reason for it besides the

Re: [julia-users] Re: Same native code, different performance

If you want to reproduce this you can use JuliaBox ( I changed cos(x) to x because it doesnt change anything) On Thursday, September 24, 2015 at 11:03:21 PM UTC+2, Erik Schnetter wrote:

Re: [julia-users] Re: Same native code, different performance

If you want to reproduce the results above and below you can use JuliaBox. This has something to do with the constant propagation of sin and cos I think. Changing cos to x reverses the results. f(x) = @fastmath x^3 f2(x) = @fastmath x^3.0 fs(x) = @fastmath cos(x)^3 fs2(x) = @fastmath

[julia-users] Re: Optimal Control using Dynamic Programming

The closest pre-made package for doing dynamic programming for optimal control would likely be one of the quantitative economics packages. If you have discrete decisions or want to grid your input space, it should be fairly straightforward to write out a cost-to-go matrix and apply the Bellman

[julia-users] Re: Request for comments: best way to deal with type uncertainty.

Le vendredi 25 septembre 2015 02:41:32 UTC+2, Ben Ward a écrit : > > As an update: We have tested fetching annotations without trying to > enforce type, and then another in which we don't. I don't understand why, > but the one in which we don't enforce type, is faster, it is also puzzling >

Re: [julia-users] Is there a way to define abstract type from a type in base.jl

Thanks,I've read about the arrays,but just don't know how to define some existed type. though a type may be define as: type a{T<:Integer}<:Real xxx end but that's will work in my function.I tried to pass different types into a function, so I asked this question. still do not understand why can

[julia-users] "WARNING: Base.String is deprecated, use AbstractString instead" en masse

Hello colleagues, the warning is quite nice, but a location would be nicer. How can i track down, which line triggered the warning? Wishing a happy day, Andreas

Re: [julia-users] Is there a way to define abstract type from a type in base.jl

I have some trouble understand your question. On Fri, Sep 25, 2015 at 8:22 AM, Roger Luo wrote: > Thanks,I've read about the arrays,but just don't know how to define some > existed type. You cannot redefine a type. Or do you mean how are certain existed types

Re: [julia-users] "WARNING: Base.String is deprecated, use AbstractString instead" en masse

On Fri, Sep 25, 2015 at 8:25 AM, Andreas Lobinger wrote: > Hello colleagues, > > the warning is quite nice, but a location would be nicer. How can i track > down, which line triggered the warning? What I did was just `grep -R` > > Wishing a happy day, > Andreas

Re: [julia-users] "WARNING: Base.String is deprecated, use AbstractString instead" en masse

> > But still, i'd prefer error messages that have more content... Yes, there are a number of open issues already about errors, warnings, and backtraces. The situation should improve when we bump to a newer LLVM version. On Fri, Sep 25, 2015 at 9:17 AM, Andreas Lobinger

Re: [julia-users] "WARNING: Base.String is deprecated, use AbstractString instead" en masse

I ran something like this to do the conversion (in bash or zsh): find . -name "*.jl" | while read i; do sed -i -e 's/\bString\b/AbstractString/g' $i; done Glen On Friday, September 25, 2015 at 9:22:44 AM UTC-4, Isaiah wrote: > > But still, i'd prefer error messages that have more content... >

[julia-users] Re: Optimal Control using Dynamic Programming

I'm biased, but for control problems with constraints I would pose it as a model predictive control problem and use JuMP.jl with the Ipopt.jl optimization solver. If you prefer to construct a cost to go map and do dynamic programming then I can't point you to any Julia code that I know of that

Re: [julia-users] Re: What are the "strengths" of the Julia "ecosystem" (e.g. for bio and quants/finance)? This is not a very specific question (while sub-questions are), you've been warned..

>From browsing issues, it looks like the HttpServer.jl performance issue you referenced below should be now fixed by https://github.com/JuliaWeb/HttpServer.jl/pull/59. On Fri, Sep 25, 2015 at 5:47 AM Páll Haraldsson wrote: > On Thursday, September 24, 2015 at 11:07:56

[julia-users] Re: Julia code 5x to 30x slower than Matlab code

all right... Well.. Julia's price will allways be better... Btw.. what about crowdfunded initiatives? Has anyone tried that? I would be wiling to donate for a geospatial visualization package, for example...

[julia-users] help!

Hi, I have 2 silly (but could find the answer yet) questions about help. 1) Is there another way to see help text besides using "?" to change the shell mode? I use software like Juno that doesn't allow that. I know that methods(function) shows a function's methods, but I wonder if there's

[julia-users] Simulation time

Hi, I am new to Julia and would like to run a set of operations repeatedly for a finite set of time. I tried to implement the following code: using JuMP, Ipopt Truck = Model(solver=IpoptSolver(print_level=0)) #Initial Values gear_0 = 1 v_0 = 20 N_0 = 600 #Constants: i_f = 3.27 eta_f = 0.95

[julia-users] Re: Optimal Control using Dynamic Programming

The system is non-linear. I have a cost function, that I need to minimize to find the optimal control to move from one state to another. There are a few constraints that the states should satisfy even. On Friday, 25 September 2015 01:20:52 UTC-5, Uwe Fechner wrote: > > Hello, > as far as I

[julia-users] Re: Optimal Control using Dynamic Programming

Hi, I am trying to control the velocity of a system optimally. I have a cost function (DP formulation) to minimize subject to a few constraints. Thanks On Friday, 25 September 2015 00:25:19 UTC-5, NV wrote: > > Hi, > I am new to Julia. I need to solve an optimal control problem using >

Re: [julia-users] "WARNING: Base.String is deprecated, use AbstractString instead" en masse

On Friday, September 25, 2015 at 2:52:43 PM UTC+2, Yichao Yu wrote: > > On Fri, Sep 25, 2015 at 8:25 AM, Andreas Lobinger > wrote: > > Hello colleagues, > > > > the warning is quite nice, but a location would be nicer. How can i > track > > down, which line triggered

Re: [julia-users] Stateflow equivalent in Julia

Welcome to Julia! To get useful answers you’re going to need to provide quite a bit more detail on what problems you’re running into. What did you try? What errors are you getting? Are there specific concepts from the documentation that you’re having trouble with? -s > On Sep 25, 2015, at

Re: [julia-users] Why two based indexing? [A package.. it's not the default..]

I understand it as a meditation (koan?) on the futility of arguing about where indices should begin, and where they come to rest. Hold it lightly, and be enlightened. -s > On Sep 25, 2015, at 7:00 AM, Páll Haraldsson > wrote: > >

Re: [julia-users] Re: Optimal Control using Dynamic Programming

Thank you for your inputs. My concern was about calculating the cost to go map. I have discretized the state space and have 61 possible states in each stages and there are 20 such stages. That roughly amounts to 61*61 values for one stage. I am overwhelmed by the amount of computations that this

Re: [julia-users] Request for comments: best way to deal with type uncertainty.

You want to type locations, i.e. arrays and fields, not function parameters and generally not local variables (although that's useful to get autoconversion behavior). On Friday, September 25, 2015, harven wrote: > > > Le vendredi 25 septembre 2015 02:41:32 UTC+2, Ben Ward a

Re: [julia-users] help!

On Fri, Sep 25, 2015 at 9:55 AM, Marcio Sales wrote: > Hi, > > I have 2 silly (but could find the answer yet) questions about help. > 1) Is there another way to see help text besides using "?" to change the > shell mode? I use software like Juno that doesn't allow that. I

Re: [julia-users] Re: How to find connected components in a matrix using Julia

Actually, Thanks, a LOT! :) Great increase in performance indeed!! :) Charles On 25 September 2015 at 11:41, Charles Novaes de Santana < charles.sant...@gmail.com> wrote: > Yes, it is my post in Stackoverflow :) > > Thanks, > > Charles > > On 25 September 2015 at 10:46, Tim Holy

Re: [julia-users] Re: Same native code, different performance

On Thursday, September 24, 2015 at 8:05:52 PM UTC, Jeffrey Sarnoff wrote: > > It could be that integer powers are done with binary shifts in software > and the floating point powers are computed in the fpu. > I suspect not. [At least in this case here, where the numbers to be raised to a power

[julia-users] Re: Julia code 5x to 30x slower than Matlab code

Then don't?

[julia-users] Re: What are the "strengths" of the Julia "ecosystem" (e.g. for bio and quants/finance)? This is not a very specific question (while sub-questions are), you've been warned..

On Thursday, September 24, 2015 at 11:07:56 PM UTC, Andrei Zh wrote: > > > >> I find this statement highly surprising.. wander if you meant to reverse >> this.. My quant friend who had worked for years in Python had trouble >> parallelizing Python code (may be resolved now..). I'm not familiar

[julia-users] [ANN] Nemo: A computer algebra package for Julia

Hi all, It is with pleasure that we release Nemo, a new computer algebra package we've been working on that uses the Julia programming language. The official announcement was made yesterday at the computer algebra minisymposium at the annual meeting of the German Mathematical Society (DMV) in

Re: [julia-users] Why two based indexing? [A package.. it's not the default..]

I think that specific repository has the additional function of testing the implementation of indexing in base, which is written with the explicit intention of being easy to extend. Two-based indexing is mostly useless, but implementing it you get the chance to explore and test all the

Re: [julia-users] Re: Julia code 5x to 30x slower than Matlab code

Marcio: crowdfunded julia packages is a really awesome idea... is there a platform for this already for other languages? or should we create one? On Fri, Sep 25, 2015 at 9:47 AM, Marcio Sales wrote: > all right... Well.. Julia's price will allways be better... > Btw..

Re: [julia-users] HDF5.jl do not support BigFloat?

The JLD package should support all Julia types. JLD uses HDF5 as backend. -erik On Fri, Sep 25, 2015 at 8:26 AM, Roger Luo wrote: > I want to write a data of a trajectory into a HDF5 file by write(or > h5write) but it seems they both do not have the method of writing a

Re: [julia-users] Stateflow equivalent in Julia

Yes, I have a transmission model to implement. I used the following code. But I need it to run for as long as I have initialized the time variable to. using JuMP, Ipopt Truck = Model(solver=IpoptSolver(print_level=0)) #Initial Values gear_0 = 1 v_0 = 20 N_0 = 600 #Constants: i_f = 3.27 eta_f =

Re: [julia-users] Re: Julia code 5x to 30x slower than Matlab code

> Marcio: crowdfunded julia packages is a really awesome idea... is there a > platform for this already for other languages? or should we create one? > > On Fri, Sep 25, 2015 at 9:47 AM, Marcio Sales > wrote: > >> all right... Well.. Julia's price will allways be