[julia-users] Re: How do I maximize a function ?

2016-11-18 Thread John Myles White
Pkg.add("Optim") then using Optim and follow this section of the docs: http://www.juliaopt.org/Optim.jl/stable/user/minimization/#minimizing-a-univariate-function --John On Friday, November 18, 2016 at 7:29:28 PM UTC-8, Pranav Bhat wrote: > > How do I obtain the maximum value of a

Re: [julia-users] Recursive data structures with Julia

2016-10-30 Thread John Myles White
Working with non-concrete types is often a problem for performance, so this approach may not be very efficient compared with alternatives that are more careful about the use of concrete types. --John On Sunday, October 30, 2016 at 6:27:47 PM UTC-7, Ralph Smith wrote: > > Conversion is done by

[julia-users] Re: Julia and the Tower of Babel

2016-10-07 Thread John Myles White
I don't really see how you can solve this without a single dictator who controls the package ecosystem. I'm not enough of an expert in Python to say how well things work there, but the R ecosystem is vastly less organized than the Julia ecosystem. Insofar as it's getting better, it's because

Re: [julia-users] Is there a way to use values in a DataFrame directly in computation?

2016-10-03 Thread John Myles White
I think the core problem is that the current API + Nullable's is very cumbersome, but the switch to Nullable's will hopefully occur nearly simultaneously with the introduction of new API's that can make Nullable's much easier to deal with. David Gold spent the summer working on one approach

[julia-users] Re: No operator overloading in DataFrames.jl?

2016-09-25 Thread John Myles White
Yes, this absence is intentional. This operation is far too magical. -- John On Sunday, September 25, 2016 at 7:49:27 PM UTC+2, nuffe wrote: > > The ability to add, subtract (etc) dataframes with automatic index > alignment is one of the great features with Pandas. Currently this is not >

[julia-users] Re: whole arrays pass by reference while matrix columns by value?

2016-09-07 Thread John Myles White
Everything is pass by sharing. But array indexing by slices creates copies. 0.5 has better support for creating views. --John On Wednesday, September 7, 2016 at 5:00:00 PM UTC-7, Alexandros Fakos wrote: > > Hi, > > a=rand(10,2) > b=rand(10) > sort!(b) modifies b > but sort!(a[:,1]) does not

Re: [julia-users] Is the master algorithm on the roadmap?

2016-09-02 Thread John Myles White
> > May I also point out to the My settings button on your top right corner > > My topic email subscriptions > Unsubscribe from this thread, which would've > spared you the message. I'm sorry, but this kind of attitude is totally unacceptable, Kevin. I've tolerated your misuse of the mailing

[julia-users] Re: Distributions.jl : generating samples from stable distributions

2016-08-19 Thread John Myles White
Unfortunately the R package is GPL, so we can't use it as a template for a Julia implementation. But RCall will let you call that package from Julia to get draws from those distributions, so you should be able to do what you suggested pretty easily. --John On Friday, August 19, 2016 at

[julia-users] Re: Distributions.jl : generating samples from stable distributions

2016-08-19 Thread John Myles White
This is extremely difficult to do right, which is why we don't support it yet. --John On Friday, August 19, 2016 at 9:26:19 AM UTC-7, Mirmu wrote: > > I am looking for generating samples from the stable Levy family with > Distributions.jl, but I cannot find it. >

[julia-users] Re: How to make a variable length tuple with inferred type

2016-08-02 Thread John Myles White
This example should clarify where you're confused: julia> typeof(ntuple(x -> 1, 1)) Tuple{Int64} julia> typeof(ntuple(x -> 1, 2)) Tuple{Int64,Int64} On Tuesday, August 2, 2016 at 2:34:27 PM UTC-5, mmh wrote: > > Care to explain in more depth? If the function is type stable i.e. it >

[julia-users] Re: A story on unchecked integer operations

2016-07-13 Thread John Myles White
This seems more like a use case for static analysis that checked operations to me. The problem IIUC isn't about the usage of high-performance code that is unsafe, but rather that the system was nominally tested, but tested in an imperfect way that didn't cover the failure cases. If you were

Re: [julia-users] When Julia v1.0 will be released?

2016-07-07 Thread John Myles White
> > For industry, it probably means something similar. I really hope people in industry won't act on this date, as it is not nearly firm enough to bet a business on. We already have people writing blog posts about how using Julia for their startup turned out to be a mistake; we really don't

[julia-users] Re: A naive benchmark

2016-07-01 Thread John Myles White
See the top of http://docs.julialang.org/en/release-0.4/manual/performance-tips/ On Friday, July 1, 2016 at 7:16:10 AM UTC-7, baillot maxime wrote: > > Hello everyone, > > I am working on a Julia code which is a brutal copy of a Matlab code and > found out that the Julia code is slower. >

[julia-users] Re: Is passing a function as an argument discouraged?

2016-06-17 Thread John Myles White
Specialization of higher-order functions should be much improved in Julia 0.5. On Friday, June 17, 2016 at 1:10:24 PM UTC-7, Douglas Bates wrote: > > I am writing a simulation function that loops over simulating a data set > and fitting multiple statistical models to the data. The exact form

[julia-users] Re: parse.(Int64, x)

2016-06-15 Thread John Myles White
I would be careful combining element-wise function application with partial function application. Why not use map instead? On Wednesday, June 15, 2016 at 3:47:05 PM UTC-7, David Anthoff wrote: > > I just tried to use the new dot syntax for vectorising function calls in > order to convert an

[julia-users] Re: Dirichlet distribution estimation ported/written in Julia?

2016-04-30 Thread John Myles White
The Lightspeed license is a little weird if I remember correctly, but it would good to get fitting procedures if we're missing them. Not sure we even have a Polya distribution right now. On Saturday, April 30, 2016 at 7:32:16 AM UTC-7, Artem OBOTUROV wrote: > > Hi > > I would like to ask if

[julia-users] Re: enforcing homogeneity of vector elements in function signature

2016-04-04 Thread John Myles White
Vector{Foo{T}}? On Monday, April 4, 2016 at 1:25:46 PM UTC-7, Davide Lasagna wrote: > > Hi all, > > Consider the following example code > > type Foo{T, N} > a::NTuple{N, T} > end > > function make_Foos(M) > fs = Foo{Float64}[] > for i = 1:M > N = rand(1:2) > f =

[julia-users] Re: What to read to understand finishing v0.5?

2016-03-09 Thread John Myles White
I think it's fair to say that the reason your questions aren't already answered by GitHub is because there's no one who's made an executive decision about the answers to those questions. -- John On Wednesday, March 9, 2016 at 4:44:28 AM UTC-8, Andreas Lobinger wrote: > > Hello colleagues, > >

[julia-users] Re: Array slices and functions that modify inputs.

2016-03-07 Thread John Myles White
Array indexing produces a brand new array that has literally no relationship with the source array. -- John On Monday, March 7, 2016 at 5:21:34 PM UTC-8, Daniel Carrera wrote: > > Hello, > > Some Julia functions act on their inputs. For example: > > julia> vals = [6,5,4,3] > 4-element

[julia-users] Re: Incomplete parametric types

2016-03-04 Thread John Myles White
Is this what you want? julia> abstract ABC julia> type A <: ABC end julia> type B <: ABC end julia> julia> type TestType{T <:ABC} a::Float64 b::T TestType(a::Float64) = new(a) end julia> myT = TestType{A}(4.0)

[julia-users] Re: Precision problem in matrix inversion (for ridge regression)?

2016-03-01 Thread John Myles White
Compare and contrast the following: inv(map(Float32, Z'*Z))*(Z'*ys_dataset) inv(map(Float64, Z'*Z))*(Z'*ys_dataset) -- John On Tuesday, March 1, 2016 at 4:19:19 PM UTC-8, Francisco C Pereira wrote: > > Hi, > > I deeply apologize in advance if this is a repeated question... the >

[julia-users] Re: Loading a module without loading its submodules

2016-02-24 Thread John Myles White
I don't think Julia is really amenable to this kind of organization because Julia's modules have no logical relationship to filesystem layouts, whereas Python's system is all about filesystem layout and has nothing to do with textual inclusion. On Wednesday, February 24, 2016 at 1:28:08 PM

[julia-users] Re: Spped, assigning arrays

2015-08-24 Thread John Myles White
You'll want to study http://julialang.org/blog/2013/09/fast-numeric/ to figure out how to make your code faster. On Monday, August 24, 2015 at 10:31:56 AM UTC-7, Mohamed Moussa wrote: Hey. I'm new to Julia. I'm playing around with 0.4 on Windows. I'm interested in writing finite element code

[julia-users] Re: Splitting a multidimensional function

2015-08-19 Thread John Myles White
Since f1(x) requires a call to f(x), there's no way for your approach to work in Julia. You probably should define f1(x) as sqrt(x[1]) and f2(x) as 2 * x[2]. -- John On Wednesday, August 19, 2015 at 2:32:38 PM UTC-7, Nikolay Kryukov wrote: I have a problem when I try to separate the

[julia-users] Re: Package description on pkg.julialang.org

2015-08-13 Thread John Myles White
Keyan, Don't worry about pkg.julialang.org. It's only updated once-a-week because it's not the definitive package listing. The listing that has day-to-day importance to user experience is the listing on METADATA.jl and the content of your package's README. Worry about those and just ignore

[julia-users] Re: New variables overwrite old variables in certain cases.

2015-07-25 Thread John Myles White
http://www.johnmyleswhite.com/notebook/2014/09/06/values-vs-bindings-the-map-is-not-the-territory/ On Saturday, July 25, 2015 at 8:13:33 AM UTC-7, Christopher Fisher wrote: I am writing a program (in .3.1) that takes a one dimensional array of indices (x) and creates a new one dimensional

Re: [julia-users] Deducing probability density functions from model equations

2015-07-21 Thread John Myles White
There's tons of WIP-code that implements arithmetic on Distributions. No one has the time to finish that code or volunteer to maintain it, so it's just sitting in limbo. OP: What you're asking for sounds like it's largely equivalent to probabilistic programming. There are a ton of ways you

[julia-users] Re: eig()/eigfact() performance: Julia vs. MATLAB

2015-07-12 Thread John Myles White
http://julia.readthedocs.org/en/release-0.3/manual/performance-tips/ On Sunday, July 12, 2015 at 8:33:56 PM UTC+2, Evgeni Bezus wrote: Hi all, I am a Julia novice and I am considering it as a potential alternative to MATLAB. My field is computational nanophotonics and the main numerical

[julia-users] Re: Too many packages?

2015-07-11 Thread John Myles White
I think most of have the opposite desire: we're trying to move more functionality out of the core language and into packages. -- John On Sunday, July 12, 2015 at 3:03:31 AM UTC+2, Burak Budanur wrote: I heard a lot about Julia language over the last year and last week had a conversation

Re: [julia-users] Re: Environment reification and lazy evaluation

2015-07-09 Thread John Myles White
to match mutable symbol tables with mutable reifications, and immutable symbol tables with immutable reifications. On Wednesday, July 8, 2015 at 6:50:03 PM UTC-4, Brandon Taylor wrote: I'm not sure I understand... On Wednesday, July 8, 2015 at 6:24:37 PM UTC-4, John Myles

Re: [julia-users] Converting a string to a custom type results in a function that is not type stable

2015-06-24 Thread John Myles White
Excited you're working on dependent data bootstraps. I implemented one just the other day since it could be useful for analyzing benchmark data. Would be great to have other methods to do out. -- John On Wednesday, June 24, 2015 at 5:31:52 AM UTC-4, Milan Bouchet-Valat wrote: Le mercredi 24

[julia-users] Re: Using composite types with many fields

2015-06-20 Thread John Myles White
It sounds like you might be better off working with Dict's instead of types. -- John On Saturday, June 20, 2015 at 12:43:03 PM UTC-7, Stef Kynaston wrote: I feel I am missing a simpler approach to replicating the behaviour of a Matlab structure. I am doing FEM, and require structure like

[julia-users] Re: Plans for Linear Algebra

2015-06-19 Thread John Myles White
Could you elaborate? What exactly is lacking? On Friday, June 19, 2015 at 6:32:36 AM UTC-7, cuneyts...@gmail.com wrote: Dear all, Considering that Julia is designed to be a scientific programming language, its built-in Linear Algebra capabilities seems to be limited (based on the users

[julia-users] Re: Distributions.jl: why use Float64 over Real when defining the functions

2015-06-19 Thread John Myles White
For many of the numerical methods in that package, people weren't sure if the code in question would generate reasonable results for other types. Some of it probably does, but it's not trivially true that evaluating those distribution on high-precision floats would produce correct results. On

[julia-users] Re: good time to start to learn julia?

2015-06-18 Thread John Myles White
My answer to these questions is always the same these days: if you're not sure that you have enough expertise to determine Julia's value for yourself, then you should be cautious and stick to playing around with Julia rather than trying to jump onboard wholesale. Julia is a wonderful language

[julia-users] Re: good time to start to learn julia?

2015-06-18 Thread John Myles White
provides. But then it's good to know whether the fundamentals like basic visualization and optimization functions are mature or not. On Thursday, June 18, 2015 at 10:57:08 AM UTC-4, John Myles White wrote: My answer to these questions is always the same these days: if you're not sure

[julia-users] Re: Multivariate optimization with bounds

2015-06-18 Thread John Myles White
Try NLopt. -- John On Thursday, June 18, 2015 at 8:35:20 AM UTC-7, Nils Gudat wrote: I'm trying to minimize a function of multiple variables using the Optim package. In my original Matlab code, I'm supplying two arrays to fmincon to set upper and lower bounds on each of the variables, but

Re: [julia-users] Re: Atom package

2015-06-12 Thread John Myles White
Should be set now. There's only an empty repo there right now at https://github.com/JuliaLang/atom-language-julia On Friday, June 12, 2015 at 2:39:29 PM UTC-7, John Myles White wrote: I can create a repo. On Friday, June 12, 2015 at 12:04:09 PM UTC-7, Spencer Lyon wrote: John, Do you

Re: [julia-users] Re: Atom package

2015-06-12 Thread John Myles White
I can create a repo. On Friday, June 12, 2015 at 12:04:09 PM UTC-7, Spencer Lyon wrote: John, Do you have create permissions within the JuliaLang github org? If not, who should we contact to create the repo/set up permissions? I guess I could just request that my repo be transferred

[julia-users] Re: Atom package

2015-06-11 Thread John Myles White
Looking into this more, it looks like the repo can have any name you want. The important thing is that the package is named language-julia, not the repo. On Thursday, June 11, 2015 at 8:05:20 PM UTC-7, Spencer Lyon wrote: Good to see something for atom-language-julia. That is what the package

[julia-users] Re: Writing a mutable function (exclamation mark function)

2015-06-08 Thread John Myles White
http://julia.readthedocs.org/en/release-0.3/manual/faq/#i-passed-an-argument-x-to-a-function-modified-it-inside-that-function-but-on-the-outside-the-variable-x-is-still-unchanged-why http://www.johnmyleswhite.com/notebook/2014/09/06/values-vs-bindings-the-map-is-not-the-territory/ On Monday,

[julia-users] Re: a simple function which changes the order of a vector (by modifying the argument)

2015-06-08 Thread John Myles White
http://julia.readthedocs.org/en/release-0.3/manual/faq/#i-passed-an-argument-x-to-a-function-modified-it-inside-that-function-but-on-the-outside-the-variable-x-is-still-unchanged-why http://www.johnmyleswhite.com/notebook/2014/09/06/values-vs-bindings-the-map-is-not-the-territory/ On Monday,

[julia-users] Re: Anonymous Objects?

2015-06-04 Thread John Myles White
https://groups.google.com/forum/#!topic/julia-users/HYhm0A8KQXw On Thursday, June 4, 2015 at 2:02:51 PM UTC-7, David Gold wrote: What is A*b? Is it just a formal multiplication? On Thursday, June 4, 2015 at 4:54:39 PM UTC-4, Gabriel Goh wrote: Do there exist anonymous objects, in the same

[julia-users] Re: [Slightly OT] Creating JuliaCon presentation slides as a Jupyter notebook

2015-06-04 Thread John Myles White
A long time ago, I did this with IJulia: https://github.com/johnmyleswhite/UCDavis.jl Hopefully most of my approach isn't relevant anymore, since I hit a couple of bugs in the resulting slides that I had to fix with a Ruby script. -- John On Thursday, June 4, 2015 at 7:49:15 AM UTC-7,

Re: [julia-users] Interop with C on an array of mutable structs

2015-06-02 Thread John Myles White
to is of type `MYSQL_BIND[]`, in which case John is correct that declaring this as `Vector{MYSQL_BIND}` (where `MYSQL_BIND` is an appropriated defined isbits type) should work exactly as desired. On Tue, Jun 2, 2015 at 11:09 AM John Myles White johnmyleswh...@gmail.com wrote: I've been

[julia-users] Interop with C on an array of mutable structs

2015-06-02 Thread John Myles White
I've been fixing up the MySQL.jl package recently. To receive data on the client-side from prepared statements, I need to pass around an array of mutable structs, defined in MySQL C's API, so that C can populate those structs with data from the server. If helpful, an example of how this works

[julia-users] Re: Does union() imply worse performance?

2015-05-30 Thread John Myles White
Myles White wrote: David, To clarify your understanding of what's wrong with DataArrays, check out the DataArray code for something like getindex(): https://github.com/JuliaStats/DataArrays.jl/blob/master/src/indexing.jl#L109 https://www.google.com/url?q=https%3A%2F%2Fgithub.com

[julia-users] Re: Does union() imply worse performance?

2015-05-30 Thread John Myles White
David, To clarify your understanding of what's wrong with DataArrays, check out the DataArray code for something like getindex(): https://github.com/JuliaStats/DataArrays.jl/blob/master/src/indexing.jl#L109 I don't have a full understanding of Julia's type inference system, but here's my

Re: [julia-users] Re: Maybe, Nullable, etc

2015-05-29 Thread John Myles White
Nullable is Julia's closest equivalent to Haskell's Maybe. But there are important differences: * Presently run-time dispatch through even a very restricted subset of types is quite costly. So you want to make sure that all code allows type inference to assign a concrete type to every value.

Re: [julia-users] Re: Maybe, Nullable, etc

2015-05-29 Thread John Myles White
To reinforce Yichao's point, using Nullables in the way you propose comes with substantial performance risks. The problem is that your strategy globally poisons type inference: type-uncertain functions don't just force run-time dispatch near the location of their function calls, they also

[julia-users] Re: IDE Julia

2015-05-20 Thread John Myles White
En general, escribimos en ingles en esta lista. Has probado Juno? -- John On Wednesday, May 20, 2015 at 3:33:08 PM UTC-7, perico garcia wrote: IDE Julia como cuando Anaconda o Spyder ?? Sería el factor determinante para la expansión del lenguaje de programación.

Re: [julia-users] Packing and Unpacking several Matrixes into flat vectors

2015-05-14 Thread John Myles White
In the long-term, the best way to do this will be to use SubArray and ReshapeArray. You'll allocate enough space for all parameters, then unpack them into separate objects when that helps. -- John On Thursday, May 14, 2015 at 2:03:27 AM UTC-7, Tim Holy wrote: Some Optim algorithms, like cg,

Re: [julia-users] Yet Another String Concatenation Thread (was: Re: Naming convention)

2015-04-28 Thread John Myles White
I think it's time for this thread to stop. People are already upset and things could easily get much worse. Let's all go back to our core work: writing packages, building infrastructure and improving Base Julia's functionality. We can discuss naming conventions when we've got the functionality

[julia-users] Re: Confused about parametrization type

2015-03-05 Thread John Myles White
Here's my perspective: * You should almost never define any type that has fields that aren't concrete types. You can achieve this in two ways: by hard-coding concrete types or by using parametric types. * You should generally avoid allocating new arrays. This means that, if your type

[julia-users] Re: Issues with optimize in Julia

2015-02-15 Thread John Myles White
Here's my two, not very thorough, cents: (1) The odds of a bug in Optim.jl are very high (90%). (2) The odds of a bug in your code are very high (90%). It's pretty easy to make a decision about (2). Deciding on (1) is a lot harder, since you need a specific optimization that Optim should solve,

[julia-users] Re: ANN: StreamStats.jl

2015-02-09 Thread John Myles White
I have seen t-digest. Ill try to implement it after getting q-digest working and then try comparing them. -- John On Monday, February 9, 2015 at 4:48:42 AM UTC-8, Stephen Lien wrote: Have you seen t-digest https://github.com/tdunning/t-digest ? Per the link: it handles doubles, uses less

[julia-users] ANN: StreamStats.jl

2015-02-07 Thread John Myles White
I've been doing a lot of streaming data analysis in Julia lately, so I finally put together a package with some core functionality for working with data streams: https://github.com/johnmyleswhite/StreamStats.jl My hope is that the community can help refine the design over time. After it's

Re: [julia-users] compilation problem on OS X for v0.4

2014-12-26 Thread John Myles White
You need to install cmake and make it available on your path: http://www.cmake.org/download/ -- John On Dec 26, 2014, at 2:07 PM, Ethan Anderes ethanande...@gmail.com wrote: Hi Everyone: I just decided to upgrade to Julia v0.4 and ran into the following error when trying to compile from

Re: [julia-users] compilation problem on OS X for v0.4

2014-12-26 Thread John Myles White
, John Myles White wrote: You need to install cmake and make it available on your path: http://www.cmake.org/download/ -- John On Dec 26, 2014, at 2:07 PM, Ethan Anderes ethana...@gmail.com wrote: Hi Everyone: I just decided to upgrade to Julia v0.4 and ran into the following error

Re: [julia-users] Julia modifies variable outside of function when operating on different variable inside of function

2014-12-26 Thread John Myles White
This is aliasing. Almost all languages allow this. -- John Sent from my iPhone On Dec 26, 2014, at 2:49 PM, Bradley Setzler bradley.setz...@gmail.com wrote: Hi, I cannot explain this behavior. I apply a function to a variable in the workspace, the function initializes its local

Re: [julia-users] Re: list of unregistered (experimental) packages

2014-12-22 Thread John Myles White
It would be really easy to run a GitHub page that is literally a list of URL’s for unofficial packages and which receives edits via GitHub pull requests. — John On Dec 22, 2014, at 12:03 PM, Stefan Karpinski ste...@karpinski.org wrote: To me the main benefit of having a list of

Re: [julia-users] Julia compatibility between versions

2014-12-20 Thread John Myles White
Julia is a _lot_ less mature than Fortran or Python. Between Julia 0.3 and Julia 1.0 I am pretty sure there will changes as substantial as the Python 2 and Python 3 changes. We've tried to provide deprecation periods for changes, but there's going to be more changes than in Fortran. -- John

Re: [julia-users] any clarification of bytes allocated in @time?

2014-12-19 Thread John Myles White
Are you timing things in the global scope? -- John On Dec 19, 2014, at 1:00 PM, John Drummond john...@gmail.com wrote: For the following code (julia 0.3.3 in windows 7 ) I don't understand what the bytes allocated in @time means All I'm doing each time is adding 10 8 byte integers

Re: [julia-users] any clarification of bytes allocated in @time?

2014-12-19 Thread John Myles White
The problem is that your let block is not a proper function body. You need to time things inside of a function body: julia function foo() @time a1 = zeros(Int64,1000) @time resize!(a1, 1000) @time resize!(a1, 1000) @time resize!(a1,

Re: [julia-users] Re: Global variables

2014-12-18 Thread John Myles White
This should get you started: http://c2.com/cgi/wiki?GlobalVariablesAreBad -- John On Dec 18, 2014, at 7:36 PM, Greg Plowman greg.plow...@gmail.com wrote: I realise my original question should have been more specific and not digress about implementing fast globals. Please bear with me as

Re: [julia-users] How do I turn a string into a variable

2014-12-17 Thread John Myles White
It's easy to write a macro that takes a static literal string and makes a variable out of it. It's much harder (maybe impossible) to write a macro that takes in a variable that happens to be bound to a string value and to make a variable out of the value you happen to have stored in that

Re: [julia-users] Re: overview questions about new doc changes (coming with v 0.4)

2014-12-17 Thread John Myles White
This debate seems a little premature to me since the definition of @doc is not totally finished yet and we need to finalize that before anyone should be adding documentation to 0.3 packages. -- John On Dec 17, 2014, at 3:15 PM, Seth catch...@bromberger.com wrote: +1. Please reconsider

Re: [julia-users] Package development - best practices

2014-12-17 Thread John Myles White
I also develop in .julia, but it's possible to use any directory as your package directory. The manual should have some sections that describe how to configure an alternative to .julia. -- John On Dec 17, 2014, at 8:15 PM, Keno Fischer kfisc...@college.harvard.edu wrote: Personally, I do

Re: [julia-users] Re: How can I sort Dict efficiently?

2014-12-16 Thread John Myles White
If you want to retain N words, perhaps a priority queue would be useful? http://julia.readthedocs.org/en/latest/stdlib/collections/#priorityqueue I'd be cautious about drawing many coding lessons from the TextAnalysis package, which has been never been optimized for performance. -- John On

Re: [julia-users] Value types

2014-12-16 Thread John Myles White
The trouble is that values aren't usually know at compile time, which is why dispatching on them doesn't work well. When values of immutables can be known at compile time, something like your proposal does work. For example, you can do this: immutable Sentinel{S} end

Re: [julia-users] Value types

2014-12-16 Thread John Myles White
I should probably point out that the type parameters being immutable is not quite right: the restriction is any bits types, which you can assess using the isbits() function on a type's name. You can find more information here: https://github.com/JuliaLang/julia/issues/6081 -- John On Dec 16,

Re: [julia-users] Value types

2014-12-16 Thread John Myles White
{:Case2}) works as expected. Thanks again Luca On Tuesday, December 16, 2014 6:57:58 PM UTC+1, John Myles White wrote: I should probably point out that the type parameters being immutable is not quite right: the restriction is any bits types, which you can assess using the isbits

Re: [julia-users] how to test NaN in an array?

2014-12-15 Thread John Myles White
You need to check isnan() per element. NaN == NaN is false, so in() fails on NaN right now. -- John On Dec 15, 2014, at 3:33 PM, Evan Pu evanthebou...@gmail.com wrote: 1 in [1,2,3] # returns true NaN in [NaN, 1.0, 2.0] # returns false how do I test if a float64 NaN is present in an

Re: [julia-users] Suspending Garbage Collection for Performance...good idea or bad idea?

2014-12-15 Thread John Myles White
This is taking the thread off-topic, but conceptually such things are possible. But Rust has a very different set of semantics for memory ownership than Julia has and is doing a lot more analysis at compile-time than Julia is doing. So Julia would need to change a lot to be more like Rust. I've

Re: [julia-users] Test approximate equality of Float16 arrays

2014-12-14 Thread John Myles White
That seems like a bug. Running something like, x = rand(Float16, 10, 10) y = rand(Float16, 10, 10) all(abs(x - y) . eps(max(maximum(x), maximum(y Gives me a true more than 80% of the time. -- John On Dec 14, 2014, at 3:26 AM, Steve Cordwell steve.cordw...@gmail.com wrote: Hi, I have

Re: [julia-users] ISLR (Gareth James, Daniela Witten, Trevor Hastie and Robert Tibshirani) Examples in Julia

2014-12-14 Thread John Myles White
This would be a great first project for someone interested in learning Julia. FWIW, the RDatasets.jl repo doesn't have anything to do with ISRL -- except insofar as ISRL decided to use common R datasets. -- John On Dec 14, 2014, at 10:36 AM, webuser1...@gmail.com wrote: I'm going through

[julia-users] Re: [WIP] CSVReaders.jl

2014-12-14 Thread John Myles White
have been elaborated enough that I'm comfortable saying that most non-pathological files will be read correctly. -- John On Dec 8, 2014, at 12:35 AM, John Myles White johnmyleswh...@gmail.com wrote: Over the last month or so, I've been slowly working on a new library that defines an abstract

Re: [julia-users] What is the use of J[:,:] = K*M please?

2014-12-14 Thread John Myles White
Assigning in-place and creating temporaries are actually totally orthogonal. One is concerned with mutating J. This is contrasted with writing, J = K * M The other is concerned with the way that K * M gets computed before any assignment operation or mutation can occur. This is contrasted with

Re: [julia-users] Announcing RobotOS.jl

2014-12-12 Thread John Myles White
Very cool. Glad you've been enjoying Julia so much, Josh. -- John On Dec 12, 2014, at 2:06 PM, Josh Langsfeld jdla...@gmail.com wrote: After about 6 weeks of initial part-time development, I'm announcing the first release of the RobotOS.jl package, which enables essentially seamless

Re: [julia-users] Roadmap

2014-12-11 Thread John Myles White
This is a very good point. I'd label this as something like core unsolved challenges. Julia #265 (https://github.com/JuliaLang/julia/issues/265) comes to mind. In general, a list of the big issues would be much easier to maintain than a list of goals for the future. We could just use a tag

Re: [julia-users] Changes to array are not visible from caller

2014-12-11 Thread John Myles White
Nope. You'll find Julia much easier to program in if you always replace x += y with x = x + y before attempting to reason about performance. In this case, you'll get x[:, :] = x[:, :] + 1.0f - 5 * dxdt In other words, you literally make a copy of the entire matrix x before doing any useful

Re: [julia-users] Is there a function that performs (1:length(v))[v] for v a Vector{Bool} or a BitArray?

2014-12-11 Thread John Myles White
Does find() work? -- John On Dec 11, 2014, at 4:19 PM, Douglas Bates dmba...@gmail.com wrote: I realize it would be a one-liner to write one but, in the interests of not reinventing the wheel, I wanted to ask if I had missed a function that does this. In R there is such a function called

Re: [julia-users] LLVM3.2 and JULIA BUILD PROBLEM

2014-12-11 Thread John Myles White
My understanding is that different versions of LLVM are enormously different and that there's no safe way to make Julia work with any version of LLVM other than the intended one. -- John On Dec 11, 2014, at 4:56 PM, Vehbi Eşref Bayraktar vehbi.esref.bayrak...@gmail.com wrote: Hi; I am

Re: [julia-users] Define composite types in a different file - constructor not defined error

2014-12-11 Thread John Myles White
You want include, not require. -- John On Dec 11, 2014, at 7:25 PM, Test This curiousle...@gmail.com wrote: I have two files: dataTypes.jl and paramcombos.jl In dataTypes.jl I have type Params . . // field names and types . end In paramcombos.jl I have

Re: [julia-users] Define composite types in a different file - constructor not defined error

2014-12-11 Thread John Myles White
. On Thursday, December 11, 2014 7:39:23 PM UTC-5, John Myles White wrote: You want include, not require. -- John On Dec 11, 2014, at 7:25 PM, Test This curiou...@gmail.com wrote: I have two files: dataTypes.jl and paramcombos.jl In dataTypes.jl I have type Params

Re: [julia-users] Weird timing issue

2014-12-11 Thread John Myles White
Are you creating a bunch of garbage? My understanding is that any garbage that gets created will be cleaned up at seemingly haphazard (but fully deterministic) points in times. -- John On Dec 11, 2014, at 11:43 PM, Sean McBane seanmc...@gmail.com wrote: Hi all, So, I'm starting to define

Re: [julia-users] Weird timing issue

2014-12-11 Thread John Myles White
Well, you're clearly allocating memory and discarding it since the list comprehension and sort both allocate memory. So that's garbage that the GC has to deal with. The GC means that your function's timing will be erratic and, generally, longer on a second pass than during the first. -- John

Re: [julia-users] Weird timing issue

2014-12-11 Thread John Myles White
This is just how the GC works. Someone who's done more work on the GC can give you more context about why the GC runs for the length of time it runs for at each specific moment that it starts going. As a favor to me, can you please make sure that you quote the entire e-mail thread you're

Re: [julia-users] Re: Aren't loops supposed to be faster?

2014-12-11 Thread John Myles White
). So, the type of the return value is stable, but I haven't found a way of informing the compiler that it is so. Petr On Thursday, December 11, 2014 8:20:20 PM UTC-8, John Myles White wrote: The moral of this story is: If you can't or won't declare every single variable

Re: [julia-users] Re: home page content

2014-12-10 Thread John Myles White
As always in Julia (and OSS in general), I think the problem is that there's no labor supply to do most nice things for the community. Everybody would love to see weekly updates. Not many people have both the time and desire to do the work. -- John On Dec 10, 2014, at 10:41 AM, Tamas Papp

Re: [julia-users] Re: home page content

2014-12-10 Thread John Myles White
Stefan, I shared your moment of terror about the idea of posting plans (essentially all of which will be invalidated) to the home page. Although it's huge volume of e-mail, I do feel like people who want to keep up with new developments in Julia should try to subscribe to the issue tracker and

Re: [julia-users] Roadmap

2014-12-10 Thread John Myles White
. On Wednesday, December 10, 2014 1:58:52 PM UTC-8, Randy Zwitch wrote: I think it would please everyone if you moved daily televised scrums. On Wednesday, December 10, 2014 4:53:50 PM UTC-5, John Myles White wrote: Stefan, I shared your moment of terror about the idea of posting plans

Re: [julia-users] Unexpected append! behavior

2014-12-10 Thread John Myles White
Hi Sean, I'm really confused by the output you're showing. X = [1,2]; Y = [1,2]; append!(X,Y) 4-element Array(Int64,1): 1 2 3 4 Do you really get this output? That seems like a huge bug if so. But I don't see that at all, which is what I'd expect. -- John

Re: [julia-users] Re: home page content

2014-12-09 Thread John Myles White
+1 for emulating the Rust site -- John On Dec 9, 2014, at 4:46 PM, Joey Huchette joehuche...@gmail.com wrote: I think the [Rust website](http://www.rust-lang.org/) is pretty fantastic, in terms of both design and content. Having the code examples runnable and editable (via JuliaBox) would

Re: [julia-users] [WIP] CSVReaders.jl

2014-12-08 Thread John Myles White
. On Mon, Dec 8, 2014 at 12:35 AM, John Myles White johnmyleswh...@gmail.com wrote: Over the last month or so, I've been slowly working on a new library that defines an abstract toolkit for writing CSV parsers. The goal is to provide an abstract interface that users can implement in order

Re: [julia-users] [WIP] CSVReaders.jl

2014-12-08 Thread John Myles White
. On Mon, Dec 8, 2014 at 12:35 AM, John Myles White johnmyleswh...@gmail.com wrote: Over the last month or so, I've been slowly working on a new library that defines an abstract toolkit for writing CSV parsers. The goal is to provide an abstract interface that users can implement in order to provide

Re: [julia-users] Re: [WIP] CSVReaders.jl

2014-12-08 Thread John Myles White
formatting, etc.) * be able to specify a end of data rule, other than end-of-file or number of lines (e.g. stop on an empty line) s On Monday, 8 December 2014 05:35:02 UTC, John Myles White wrote: Over the last month or so, I've been slowly working on a new library that defines an abstract

Re: [julia-users] [WIP] CSVReaders.jl

2014-12-08 Thread John Myles White
other alternative, because we have a really fast transpose now. The only disadvantage I see is taking twice as much memory as would be minimally needed. (This can be fixed once we have row-major arrays.) --Tim On Monday, December 08, 2014 08:38:06 AM John Myles White wrote: I believe

Re: [julia-users] [WIP] CSVReaders.jl

2014-12-08 Thread John Myles White
time (compared to the I/O)? --Tim On Monday, December 08, 2014 09:14:35 AM John Myles White wrote: Yes, this is how I've been doing things so far. -- John On Dec 8, 2014, at 9:12 AM, Tim Holy tim.h...@gmail.com wrote: My suspicion is you should read into a 1d vector (and use `append

Re: [julia-users] Re: [WIP] CSVReaders.jl

2014-12-08 Thread John Myles White
at the start). -- John On Dec 8, 2014, at 9:24 AM, Simon Byrne simonby...@gmail.com wrote: On Monday, 8 December 2014 17:04:10 UTC, John Myles White wrote: * This package and the current DataFrames code both support specifying the types of all columns before parsing begins. There's no fast path

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