Re: [julia-users] Julia users Berlin

[David Higgins]

Sorry all, that was a mispost (sent by email). But since I did it, here is 
the link to the Julia Users Berlin discussion group. Please join if you 
want to attend the meet-ups here in Berlin:

https://groups.google.com/forum/#!members/julia-users-berlin

David.


On Thursday, 16 June 2016 17:26:10 UTC+2, David Higgins wrote:
>
> Felix, 
>
> Please join the (Julia Users Berlin) Google Group to find out about the 
> next meetup. 
>
> David. 
>
> On 25/03/2015 11:54, Felix Jung wrote: 
> > Sorry guys. Would have loved to come but can't make it on that date. If 
> > we make this a regular thing I'd be happy to participate in an active 
> > manner. 
> > 
> > Have fun, 
> > 
> > Felix 
> > 
> > On 25 Mar 2015, at 09:37, David Higgins <daithio...@gmail.com 
>  
> > <mailto:daithio...@gmail.com >> wrote: 
> > 
> >> Both times are fine with me, I just need to change the reservation if 
> >> we go with that. 
> >> 
> >> By my count, from the thread above the following people are probably 
> >> coming: 
> >> Viral Shah 
> >> Simon Danisch 
> >> Felix Schueler 
> >> David Higgins 
> >> Felix Jung? ("wow, cool stuff" :) ) 
> >> Fabian Gans?? (Jena) 
> >> One other person contacted me off-list to say they'll come if some 
> >> travel arrangements work out. 
> >> 
> >> The first four are ok with an earlier meeting time. I imagine it's 
> >> getting late for Fabian to arrange a train from Jena, but 5pm would 
> >> certainly work better for him. 
> >> 
> >> So, any objections to changing from 7pm to 5pm? (ie. who's lurking out 
> >> there and hasn't replied yet but was hoping to come?) 
> >> 
> >> David. 
> >> 
> >> On Wednesday, 25 March 2015 07:26:16 UTC+1, Viral Shah wrote: 
> >> 
> >> How about we aim for 5pm in that case? I think I can make it by 
> >> then. Does that work for others? 
> >> 
> >> -viral 
> >> 
> >> On Tuesday, March 24, 2015 at 11:07:40 AM UTC+1, Simon Danisch 
> wrote: 
> >> 
> >> My train leaves at 9pm (at least the train station is close), 
> >> so I'd probably go there 1-2 hours early and see who drops by. 
> >> Felix Schüler would come earlier as well ;) 
> >> @David Higgins 
> >> Do we need to call them to adjust this properly? 
> >> 
> >> On 24 Mar 2015 08:56, "Fabian Gans" <fabia...@gmail.com 
> >> > wrote: 
> >> 
> >> I will not be there. 7 seems to be too late for me to get 
> >> back to Jena the same day. 
> >> 
> >> Fabian 
> >> 
>

Re: [julia-users] Julia users Berlin

[David Higgins]

Felix,

Please join the (Julia Users Berlin) Google Group to find out about the
next meetup.

David.

On 25/03/2015 11:54, Felix Jung wrote:
> Sorry guys. Would have loved to come but can't make it on that date. If
> we make this a regular thing I'd be happy to participate in an active
> manner.
> 
> Have fun,
> 
> Felix
> 
> On 25 Mar 2015, at 09:37, David Higgins <daithiohuig...@gmail.com
> <mailto:daithiohuig...@gmail.com>> wrote:
> 
>> Both times are fine with me, I just need to change the reservation if
>> we go with that.
>>
>> By my count, from the thread above the following people are probably
>> coming:
>> Viral Shah
>> Simon Danisch
>> Felix Schueler
>> David Higgins
>> Felix Jung? ("wow, cool stuff" :) )
>> Fabian Gans?? (Jena)
>> One other person contacted me off-list to say they'll come if some
>> travel arrangements work out.
>>
>> The first four are ok with an earlier meeting time. I imagine it's
>> getting late for Fabian to arrange a train from Jena, but 5pm would
>> certainly work better for him.
>>
>> So, any objections to changing from 7pm to 5pm? (ie. who's lurking out
>> there and hasn't replied yet but was hoping to come?)
>>
>> David.
>>
>> On Wednesday, 25 March 2015 07:26:16 UTC+1, Viral Shah wrote:
>>
>> How about we aim for 5pm in that case? I think I can make it by
>> then. Does that work for others?
>>
>> -viral
>>
>> On Tuesday, March 24, 2015 at 11:07:40 AM UTC+1, Simon Danisch wrote:
>>
>> My train leaves at 9pm (at least the train station is close),
>> so I'd probably go there 1-2 hours early and see who drops by.
>> Felix Schüler would come earlier as well ;)
>> @David Higgins
>> Do we need to call them to adjust this properly?
>>
>> On 24 Mar 2015 08:56, "Fabian Gans" <fabia...@gmail.com
>> > wrote:
>>
>> I will not be there. 7 seems to be too late for me to get
>> back to Jena the same day.
>>
>> Fabian
>>

[julia-users] Re: Julia Users Berlin

[David Higgins]

Don't forget: Meet-up this Thursday in Berlin for any who want to come 
along!

David.

On Monday, 30 May 2016 15:16:08 UTC+2, David Higgins wrote:
>
> Hi all,
>
> I gave a talk at the recent PyData Berlin conference (
> http://pydata.org/berlin2016/) and there seems to be enough interest in 
> forming a regular users group in the city. Some of you may recall that we 
> had a preliminary meeting a year ago, which happened to coincide with Viral 
> Shah being within striking distance and he came along, but at the time none 
> of us were really ready to make it a regular event.
>
> A year is a long time in the life of a Julia user. Now there are more of 
> us and we'd like to meet up again.
>
> On *Thursday June 9th *at* 7pm*, we're going to meet at St Oberholz 
> (Rosenthaler 
> Str. 72A, 10119 Berlin). Miles Lubin from JuMP happens to be in town, so 
> the topics of the night might include (i) numerical optimisation and (ii) 
> how to organise more regular meetings (topics, location). So please come 
> along. The reservation is in the name Robert Schwarz and based on previous 
> experience we'll probably be upstairs at the back of the room.
>
> By the way, I've created a landing page for a Julia Users Group - Berlin 
> on GitHub. Feel free to contribute. http://julia-users-berlin.github.io/
>
> David Higgins
>
>

Re: [julia-users] Julia users Berlin

[David Higgins]

Hi all,

I've announced a new meet-up with a visiting speaker 
here https://groups.google.com/forum/#!topic/julia-users/S3eMY64c_dE

Hope to see you in two weeks.

David.

On Thursday, 26 March 2015 22:55:02 UTC+1, Max Suster wrote:
>
>
> I would have loved to join too, but it was too short notice for me. . .
> I will definitely do this regularly (and be happy to help) once I have 
> settled in Berlin. 
>
> Max
>
> On Wednesday, March 25, 2015 at 4:19:01 PM UTC+1, David Higgins wrote:
>>
>> Reservation changed:
>>
>> Thursday, 26th March, *5pm* at St. Oberholz, Rosenthaler Straße 72A
>>
>> It's still in my name (Higgins).
>>
>> Looking forward to seeing you then,
>> David.
>>
>> On Wednesday, 25 March 2015 15:05:07 UTC+1, Keyan wrote:
>>>
>>> I won’t make it either, but I hope that I can join in on some other day.
>>>
>>> Cheers,
>>> Keyan
>>>
>>> On 25 Mar 2015, at 11:54, Felix Jung <fe...@jung.fm> wrote:
>>>
>>> Sorry guys. Would have loved to come but can't make it on that date. If 
>>> we make this a regular thing I'd be happy to participate in an active 
>>> manner.
>>>
>>> Have fun,
>>>
>>> Felix
>>>
>>> On 25 Mar 2015, at 09:37, David Higgins <daithio...@gmail.com> wrote:
>>>
>>> Both times are fine with me, I just need to change the reservation if we 
>>> go with that.
>>>
>>> By my count, from the thread above the following people are probably 
>>> coming:
>>> Viral Shah
>>> Simon Danisch
>>> Felix Schueler
>>> David Higgins
>>> Felix Jung? ("wow, cool stuff" :) )
>>> Fabian Gans?? (Jena)
>>> One other person contacted me off-list to say they'll come if some 
>>> travel arrangements work out.
>>>
>>> The first four are ok with an earlier meeting time. I imagine it's 
>>> getting late for Fabian to arrange a train from Jena, but 5pm would 
>>> certainly work better for him.
>>>
>>> So, any objections to changing from 7pm to 5pm? (ie. who's lurking out 
>>> there and hasn't replied yet but was hoping to come?)
>>>
>>> David.
>>>
>>> On Wednesday, 25 March 2015 07:26:16 UTC+1, Viral Shah wrote:
>>>>
>>>> How about we aim for 5pm in that case? I think I can make it by then. 
>>>> Does that work for others?
>>>>
>>>> -viral
>>>>
>>>> On Tuesday, March 24, 2015 at 11:07:40 AM UTC+1, Simon Danisch wrote:
>>>>>
>>>>> My train leaves at 9pm (at least the train station is close), so I'd 
>>>>> probably go there 1-2 hours early and see who drops by.
>>>>> Felix Schüler would come earlier as well ;)
>>>>> @David Higgins
>>>>> Do we need to call them to adjust this properly?
>>>>> On 24 Mar 2015 08:56, "Fabian Gans" <fabia...@gmail.com> wrote:
>>>>>
>>>>>> I will not be there. 7 seems to be too late for me to get back to 
>>>>>> Jena the same day. 
>>>>>>
>>>>>> Fabian
>>>>>>
>>>>>
>>>

[julia-users] Julia Users Berlin

[David Higgins]

Hi all,

I gave a talk at the recent PyData Berlin conference 
(http://pydata.org/berlin2016/) and there seems to be enough interest in 
forming a regular users group in the city. Some of you may recall that we 
had a preliminary meeting a year ago, which happened to coincide with Viral 
Shah being within striking distance and he came along, but at the time none 
of us were really ready to make it a regular event.

A year is a long time in the life of a Julia user. Now there are more of us 
and we'd like to meet up again.

On *Thursday June 9th *at* 7pm*, we're going to meet at St Oberholz 
(Rosenthaler 
Str. 72A, 10119 Berlin). Miles Lubin from JuMP happens to be in town, so 
the topics of the night might include (i) numerical optimisation and (ii) 
how to organise more regular meetings (topics, location). So please come 
along. The reservation is in the name Robert Schwarz and based on previous 
experience we'll probably be upstairs at the back of the room.

By the way, I've created a landing page for a Julia Users Group - Berlin on 
GitHub. Feel free to contribute. http://julia-users-berlin.github.io/

David Higgins

Re: [julia-users] Re: Juno + Julia 0.4

[David Higgins]

If you're lucky you might find that the Meta key works (try the Windows key 
if you have one). On my Mac the Alt key is not being correctly captured by 
Atom, so none of the related shortcuts are working.

I'm using Atom now and I have to say that when it works it works 
beautifully, but the devs seem to be a bit blind to the idea that people 
might have different work patterns from themselves. Divining for oneself 
that you need to press Esc to exit the Find panel is not intuitive but 
works very nicely once you know (although the vi-keybindings guys are 
suffering on that one it seems). Reading the online discussions on these 
matters is a strange insight into their thought processes.

David.

On Friday, 18 September 2015 18:54:03 UTC+2, Sisyphuss wrote:
>
> However, Atom also has heavy use of "ctrl". For instance, "ctrl + P" to 
> move forward, as indicated in the documentation, has other effect on my 
> computer.
>
> Furthermore, most "Alt" key bindings are mapped to menu operation on my 
> computer.
>
>
>
> On Friday, September 18, 2015 at 6:49:41 PM UTC+2, Spencer Russell wrote:
>>
>> Most keyboard shortcuts that use “cmd” on OSX are replaced by “ctrl” on 
>> Linux. 
>>
>> -s 
>>
>> > On Sep 18, 2015, at 12:46 PM, Sisyphuss  wrote: 
>> > 
>> > I have just read the documentation of Atom. I wonder how could you use 
>> it in a Linux keyboard, where there is no "cmd" key. 
>> > 
>>
>>

[julia-users] Re: Package update which broke my Python link

[David Higgins]

Thanks guys. 

The update() and build() calls didn't fix it. But a checkout() of PyCall 
followed by a new call to build() worked it out.

I don't actually use IJulia. I installed it so that I could demonstrate it 
to colleagues. Guess I'll leave it uninstalled for now :)

Dave.

On Monday, 14 September 2015 18:10:21 UTC+2, John Pearson wrote:
>
> Steven (PyCall author) posted on this a few days ago.
>
> The bug has been fixed, you just need to
>
> Pkg.checkout("PyCall")
>
> which will get the latest version of the code from master.
>
> Note, though, that even with this fixed, I'm having some problems with 
> plotting in the IJulia notebook (dead kernels), though things work just 
> fine from the REPL.
>
> On Monday, September 14, 2015 at 11:53:51 AM UTC-4, David Higgins wrote:
>>
>> Hi,
>>
>> I'm not sure where exactly my problem is located (in code/interfaces) so 
>> any help would be appreciated.
>>
>> I did an update of all of my packages a few nights ago and ran into the 
>> same problem detailed here:
>> https://groups.google.com/d/msg/julia-users/XqzNceNwa2Y/ZhahE-kQAwAJ
>> Basically the 'cp()' command was being called during the IJulia update 
>> with a parameter which was not valid in v0.3 of Julia. So that particular 
>> update bombed out.
>>
>> I didn't initially realise, however I have not done any other changes on 
>> my system in the interim, but my ability to access Python libraries via 
>> PyCall has been broken since that update. My main use is via PyPlot. This 
>> is really killing me for work, I had moved entirely to Julia, so I really 
>> need to sort this out.
>>
>> The best reduction of the problem which I can find is the following:
>>
>> julia> using PyCall
>>
>> julia> @pyimport math
>>
>> Could not find platform independent libraries 
>>
>> Could not find platform dependent libraries 
>>
>> Consider setting $PYTHONHOME to [:]
>>
>> ImportError: No module named site
>>
>> I don't typically use Python, so I'm not much good at it, but I can see 
>> that this is the error you would normally get if the python libraries were 
>> not where they're supposed to be (and is generated in Python not Julia). I 
>> just have the regular Anaconda installation in order to provide matplotlib 
>> access to Julia. Python is still working fine from the command-line and has 
>> full access to its libraries.
>>
>> I've tried deleting the Anaconda installation and doing a re-install. 
>> I've also tried deleting and reinstalling Julia. It seems to me that either 
>> I'm missing an environment setting somewhere, or there's a new bug in one 
>> of my libraries (PyCall??), or a file somehow got deleted during the failed 
>> call to cp().
>>
>> I'm working on a Mac. Oh, and Julia completely crashes after this error!
>>
>> Anybody able to give advice or help? Please.
>>
>> Thanks,
>> David.
>>
>

[julia-users] Re: Juno + Julia 0.4

[David Higgins]

The julia-client package for Atom is from the Juno project. It requires 
Julia 0.4 so I haven't tried it yet. But there is support for syntax 
highlighting from the language-julia package.

I've started using Atom, it's quite nice. But there is no project support 
yet, which really sucks from my point of view. I find the editor slightly 
more intuitive than Sublime Text, which many aspects of it are blatantly 
modelled on, but without support for projects it's only good for a certain 
style of coding.

David.

On Tuesday, 15 September 2015 14:34:26 UTC+2, Sisyphuss wrote:
>
> Thanks, both. By the way, is there any relation between Juno and Atom? 
> What's the trend?
>
>
>
> On Tuesday, September 15, 2015 at 1:59:55 PM UTC+2, Nils Gudat wrote:
>>
>> Yes, it does (that's the point of having the bundle(!) available on the 
>> website).
>> To connect to a different instance of Julia, follow the steps here: 
>> http://junolab.org/docs/install-manual.html
>> However, I don't think JunoLT is working with 0.4 (at least it wasn't 
>> when I last checked two weeks ago), and in general efforts have shifted to 
>> the new Juno Atom client.
>>
>> Long story short, if you want to work in 0.4 you should probably do this: 
>> https://github.com/JunoLab/atom-julia-client/tree/master/manual
>>
>

[julia-users] Re: Juno + Julia 0.4

[David Higgins]

Scott,

Yes, I did. It would be perfect if only it supported maintaining a list of 
open files on a per project basis. I have two, highly related, (scientific) 
projects in the same folder and unfortunately project-manager assumes that 
you keep your projects in separate folders. I had a highly effective 
workflow in Sublime Text where each project knew which files I was using 
(open) within that project and I could switch between them easily. 
'project-ring' almost fits my needs but it's a little bit flaky still, and 
I'm beginning to realise that I'd like to have the project definition file 
within the project folder for easy synchronisation between computers.

David.

On Tuesday, 15 September 2015 15:12:51 UTC+2, Scott T wrote:
>
> Have you tried the project-manager package? It has some support for 
> defining and switching between projects.
>
> Scott
>
> On Tuesday, 15 September 2015 14:06:03 UTC+1, David Higgins wrote:
>>
>> The julia-client package for Atom is from the Juno project. It requires 
>> Julia 0.4 so I haven't tried it yet. But there is support for syntax 
>> highlighting from the language-julia package.
>>
>> I've started using Atom, it's quite nice. But there is no project support 
>> yet, which really sucks from my point of view. I find the editor slightly 
>> more intuitive than Sublime Text, which many aspects of it are blatantly 
>> modelled on, but without support for projects it's only good for a certain 
>> style of coding.
>>
>> David.
>>
>> On Tuesday, 15 September 2015 14:34:26 UTC+2, Sisyphuss wrote:
>>>
>>> Thanks, both. By the way, is there any relation between Juno and Atom? 
>>> What's the trend?
>>>
>>>
>>>
>>> On Tuesday, September 15, 2015 at 1:59:55 PM UTC+2, Nils Gudat wrote:
>>>>
>>>> Yes, it does (that's the point of having the bundle(!) available on the 
>>>> website).
>>>> To connect to a different instance of Julia, follow the steps here: 
>>>> http://junolab.org/docs/install-manual.html
>>>> However, I don't think JunoLT is working with 0.4 (at least it wasn't 
>>>> when I last checked two weeks ago), and in general efforts have shifted to 
>>>> the new Juno Atom client.
>>>>
>>>> Long story short, if you want to work in 0.4 you should probably do 
>>>> this: https://github.com/JunoLab/atom-julia-client/tree/master/manual
>>>>
>>>

[julia-users] Package update which broke my Python link

[David Higgins]

Hi,

I'm not sure where exactly my problem is located (in code/interfaces) so 
any help would be appreciated.

I did an update of all of my packages a few nights ago and ran into the 
same problem detailed here:
https://groups.google.com/d/msg/julia-users/XqzNceNwa2Y/ZhahE-kQAwAJ
Basically the 'cp()' command was being called during the IJulia update with 
a parameter which was not valid in v0.3 of Julia. So that particular update 
bombed out.

I didn't initially realise, however I have not done any other changes on my 
system in the interim, but my ability to access Python libraries via PyCall 
has been broken since that update. My main use is via PyPlot. This is 
really killing me for work, I had moved entirely to Julia, so I really need 
to sort this out.

The best reduction of the problem which I can find is the following:

julia> using PyCall

julia> @pyimport math

Could not find platform independent libraries 

Could not find platform dependent libraries 

Consider setting $PYTHONHOME to [:]

ImportError: No module named site

I don't typically use Python, so I'm not much good at it, but I can see 
that this is the error you would normally get if the python libraries were 
not where they're supposed to be (and is generated in Python not Julia). I 
just have the regular Anaconda installation in order to provide matplotlib 
access to Julia. Python is still working fine from the command-line and has 
full access to its libraries.

I've tried deleting the Anaconda installation and doing a re-install. I've 
also tried deleting and reinstalling Julia. It seems to me that either I'm 
missing an environment setting somewhere, or there's a new bug in one of my 
libraries (PyCall??), or a file somehow got deleted during the failed call 
to cp().

I'm working on a Mac. Oh, and Julia completely crashes after this error!

Anybody able to give advice or help? Please.

Thanks,
David.

[julia-users] Re: Error: cp does not accept keyword arguments

[David Higgins]

This is a big one. It happened to me last night and it turns out that Julia 
crashes every time I try to call a Python library from it now.

I've just done a reinstall and it still hasn't fixed it.

I need this to prepare some figures for tomorrow morning, so I'd really 
appreciate any quick help.

Thanks,
Dave.

On Saturday, 12 September 2015 21:29:30 UTC+2, ques...@sky.com wrote:
>
> Hello All,
>
> I have just tried a clean install of Julia and on adding IJulia got the 
> following:
>
> Found jupyter kernelspec version 4.0.0 ... ok.
> Writing IJulia kernelspec to julia-0.3/kernel.json ...
> [ ERROR: IJulia 
> ]=
>
> function cp does not accept keyword arguments
> while loading /home/martin/.julia/v0.3/IJulia/deps/build.jl, in 
> expression starting on line 66
>
>
> IJulia built quite happily earlier today, so I can only assume something 
> has been changed today.
> Regards
> Martin
>
>

Re: [julia-users] Re: Error: cp does not accept keyword arguments

[David Higgins]

Well, you're right that the original problem comes from the install of 
IJulia. And it was generated because the IJulia code is using a version of 
cp() which does not exist in v0.3. But that was the only error generated 
and since then my julia crashes every time I try to use python from it (via 
PyCall, as you said).

Dave.

On Sunday, 13 September 2015 21:28:54 UTC+2, Yichao Yu wrote:
>
> On Sun, Sep 13, 2015 at 3:17 PM, David Higgins <daithio...@gmail.com 
> > wrote: 
> > This is a big one. It happened to me last night and it turns out that 
> Julia 
> > crashes every time I try to call a Python library from it now. 
> > 
> > I've just done a reinstall and it still hasn't fixed it. 
> > 
> > I need this to prepare some figures for tomorrow morning, so I'd really 
> > appreciate any quick help. 
>
> AFAICT, The original issue only happens when installing IJulia and is 
> because of the use of a 0.4 function in the IJulia install script. 
> Your problem sounds like sth to do with the PyCall rather than IJulia 
> so it is almost certainly not the same problem. 
>
> > 
> > Thanks, 
> > Dave. 
> > 
> > 
> > On Saturday, 12 September 2015 21:29:30 UTC+2, ques...@sky.com wrote: 
> >> 
> >> Hello All, 
> >> 
> >> I have just tried a clean install of Julia and on adding IJulia got the 
> >> following: 
> >> 
> >> Found jupyter kernelspec version 4.0.0 ... ok. 
> >> Writing IJulia kernelspec to julia-0.3/kernel.json ... 
> >> [ ERROR: IJulia 
> >> ]= 
> >> 
> >> function cp does not accept keyword arguments 
> >> while loading /home/martin/.julia/v0.3/IJulia/deps/build.jl, in 
> expression 
> >> starting on line 66 
> >> 
> >> 
> >> IJulia built quite happily earlier today, so I can only assume 
> something 
> >> has been changed today. 
> >> Regards 
> >> Martin 
> >> 
> > 
>

[julia-users] Re: Multidimensional linear extrapolation on irregular grid

[David Higgins]

As far as I know Grid.jl also supports irregular grids (InterpIrregular), 
although it basically does this by invisibly filling in a finer grain grid 
than you asked for (if my memory of looking through the code is correct). 
It can't extrapolate beyond the grid edge however.

Dave.


On Monday, 31 August 2015 13:45:19 UTC+2, Nils Gudat wrote:
>
> Is there a package that can do a multidimensional (3D and higher) linear 
> interpolation on an irregular grid, and extrapolate values beyond 
> gridpoints?
> From what I can see:
>
> - Grid.jl can do linear extrapolation, but only on regular grids
> - The same is true for Interpolations.jl
> - ApproXD supports irregular grids, but only flat boundary conditions
> - Dierckx.jl only works in 2 dimensions
> - GridInterpolations.jl only works on simplex and rectangle grids (not 
> exactly sure how it works as I haven't used it)
>
> Am I missing anything? 
>
> I'm basically looking for a simple interpolant to a function f(x,y,z), 
> that given irregular grids for x, y, and z can supply a value for e.g. 
> f(x, y, z[end] + 0.1) by simply using the slope of the function between 
> z[end-1] 
> and z[end], holding x and y constant. 
>

Re: [julia-users] Julia users Berlin

[David Higgins]

Both times are fine with me, I just need to change the reservation if we go 
with that.

By my count, from the thread above the following people are probably coming:
Viral Shah
Simon Danisch
Felix Schueler
David Higgins
Felix Jung? (wow, cool stuff :) )
Fabian Gans?? (Jena)
One other person contacted me off-list to say they'll come if some travel 
arrangements work out.

The first four are ok with an earlier meeting time. I imagine it's getting 
late for Fabian to arrange a train from Jena, but 5pm would certainly work 
better for him.

So, any objections to changing from 7pm to 5pm? (ie. who's lurking out 
there and hasn't replied yet but was hoping to come?)

David.

On Wednesday, 25 March 2015 07:26:16 UTC+1, Viral Shah wrote:

 How about we aim for 5pm in that case? I think I can make it by then. Does 
 that work for others?

 -viral

 On Tuesday, March 24, 2015 at 11:07:40 AM UTC+1, Simon Danisch wrote:

 My train leaves at 9pm (at least the train station is close), so I'd 
 probably go there 1-2 hours early and see who drops by.
 Felix Schüler would come earlier as well ;)
 @David Higgins
 Do we need to call them to adjust this properly?
 On 24 Mar 2015 08:56, Fabian Gans fabia...@gmail.com javascript: 
 wrote:

 I will not be there. 7 seems to be too late for me to get back to Jena 
 the same day. 

 Fabian

Re: [julia-users] Julia users Berlin

[David Higgins]

Reservation changed:

Thursday, 26th March, *5pm* at St. Oberholz, Rosenthaler Straße 72A

It's still in my name (Higgins).

Looking forward to seeing you then,
David.

On Wednesday, 25 March 2015 15:05:07 UTC+1, Keyan wrote:

 I won’t make it either, but I hope that I can join in on some other day.

 Cheers,
 Keyan

 On 25 Mar 2015, at 11:54, Felix Jung fe...@jung.fm javascript: wrote:

 Sorry guys. Would have loved to come but can't make it on that date. If we 
 make this a regular thing I'd be happy to participate in an active manner.

 Have fun,

 Felix

 On 25 Mar 2015, at 09:37, David Higgins daithio...@gmail.com 
 javascript: wrote:

 Both times are fine with me, I just need to change the reservation if we 
 go with that.

 By my count, from the thread above the following people are probably 
 coming:
 Viral Shah
 Simon Danisch
 Felix Schueler
 David Higgins
 Felix Jung? (wow, cool stuff :) )
 Fabian Gans?? (Jena)
 One other person contacted me off-list to say they'll come if some travel 
 arrangements work out.

 The first four are ok with an earlier meeting time. I imagine it's getting 
 late for Fabian to arrange a train from Jena, but 5pm would certainly work 
 better for him.

 So, any objections to changing from 7pm to 5pm? (ie. who's lurking out 
 there and hasn't replied yet but was hoping to come?)

 David.

 On Wednesday, 25 March 2015 07:26:16 UTC+1, Viral Shah wrote:

 How about we aim for 5pm in that case? I think I can make it by then. 
 Does that work for others?

 -viral

 On Tuesday, March 24, 2015 at 11:07:40 AM UTC+1, Simon Danisch wrote:

 My train leaves at 9pm (at least the train station is close), so I'd 
 probably go there 1-2 hours early and see who drops by.
 Felix Schüler would come earlier as well ;)
 @David Higgins
 Do we need to call them to adjust this properly?
 On 24 Mar 2015 08:56, Fabian Gans fabia...@gmail.com wrote:

 I will not be there. 7 seems to be too late for me to get back to Jena 
 the same day. 

 Fabian

Re: [julia-users] Julia users Berlin

[David Higgins]

Reservation made in the name of Higgins, for 7pm on Thursday. If anyone has 
trouble finding us they can call 01578 -4-30-50-44.

St. Oberholz, Rosenthaler Straße 72A, 10119 Berlin

I've booked for 8 people; I think that's reasonable for now. Please post 
your attendance in this thread so that I can change the booking if we're 
likely to be twice that number.

See you then!

David.

On Monday, 23 March 2015 11:16:12 UTC+1, Viral Shah wrote:

 Sounds like a plan. Let’s reserve a table. Seems like there already are 
 3-4 people interested. 

 -viral 



  On 23-Mar-2015, at 11:05 am, David Higgins daithio...@gmail.com 
 javascript: wrote: 
  
  I'd like to suggest: 
  
  Thursday 26th March, 7pm at St. Oberholz (Rosenthaler Straße 72A) 
  
  It's one of those co-working places with a bar/cafe/restaurant on the 
 ground floor. We could reserve a table in the cafe and just see who shows 
 up. I can call them if that sounds reasonable. 
  
  If people are constrained to a daytime meetup I can probably arrange 
 space at the TU (Ernst-Reuter Platz), it's holiday time so the place is 
 empty. 
  
  David. 
  
  On Monday, 23 March 2015 10:53:39 UTC+1, Fabian Gans wrote: 
  Hi all, 
  
  I am based in Jena and in case you organize a meeting on Thursday, I 
 would be interested to join. Please let me know about your plans. 
  
  Fabian 

[julia-users] Re: Julia users Berlin

[David Higgins]

I'd like to suggest:

*Thursday 26th March, 7pm* at* St. Oberholz (Rosenthaler Straße 72A)*

It's one of those co-working places with a bar/cafe/restaurant on the 
ground floor. We could reserve a table in the cafe and just see who shows 
up. I can call them if that sounds reasonable.

If people are constrained to a daytime meetup I can probably arrange space 
at the TU (Ernst-Reuter Platz), it's holiday time so the place is empty.

David.

On Monday, 23 March 2015 10:53:39 UTC+1, Fabian Gans wrote:

 Hi all, 

 I am based in Jena and in case you organize a meeting on Thursday, I would 
 be interested to join. Please let me know about your plans. 

 Fabian

Re: [julia-users] Julia users Berlin

[David Higgins]

I haven't set anything up yet. I have been working in Cambridge. I'll be 
back in Berlin from tonight.

I would be very interested in meeting you guys too. Wednesday and Friday 
night would work best for me, but if necessary I'll come on Thursday.

David.


On Sunday, 22 March 2015 10:56:28 UTC, Viral Shah wrote:

 Thinking of being there Thursday-Saturday. 

 -viral 


  On 22-Mar-2015, at 11:54 am, Simon Danisch sdan...@gmail.com 
 javascript: wrote: 
  
  I could schedule my Berlin visit for this time frame. 
  When exactly would you be in Berlin? 
  I could stay in Berlin up to Friday. 
  
  Best, 
  Simon 
  
  Am Mittwoch, 25. Februar 2015 14:35:13 UTC+1 schrieb David Higgins: 
  Hi all, 
  
  I'm based at the Technical University in Berlin and I've more or less 
 completed the transition to using Julia for all of my research (I still use 
 OpenCL for bigger projects). I'm just wondering if there are other Berlin 
 based Julia users/developers who want to meet up from time to time to share 
 tips, etc. 
  
  David. 

Re: [julia-users] Re: Getting people to switch to Julia - tales of no(?) success

[David Higgins]

Thank you, by the way.

David.

On Thursday, 5 March 2015 15:17:25 UTC+1, David Higgins wrote:

 :D I suck! 

 On Thursday, 5 March 2015 15:14:59 UTC+1, Ivar Nesje wrote:

  I'd also like a REPL command which prints out a list of all of the 
 objects currently in memory space (like 'whos' in Octave)

 I'd recommend you try the obscurely named whos() in Julia :)

 torsdag 5. mars 2015 14.38.05 UTC+1 skrev David Higgins følgende:

 Oh, and an IDE is the other requirement of my hard core programming 
 brethren. The debugger is higher on their list of priorities, but the IDE 
 is also vital (and one capable of handling projects, etc. we do large scale 
 numerical projects).

 David.

 On Thursday, 5 March 2015 14:35:23 UTC+1, David Higgins wrote:

 I agree with many of the comments above. I recommend Julia only to a 
 subset of my colleagues. From Matlab the barrier to entry is incredibly 
 low 
 and you gain on both speed and price, the only argument against is that 
 Matlab users tend to have years of experience in their one language and 
 not 
 such a habit of learning new languages.

 I personally moved from mainly GPGPU based programming using C; despite 
 the difficulty of that field I found the move painful due to a lack of 
 detailed documentation (my perception). Don't get me wrong, there's enough 
 documentation out there to make a decent stab at getting things done. But 
 I'm used to having a much more nuanced understanding of a language and the 
 documentation doesn't yet go into this level of detail, nor are there 
 sufficient examples out there.

 For my colleagues who are strong programmers (Python particularly), 
 they refuse to touch the language until there's a debugger. At the very 
 least they want to be able to set breakpoints and run to them. Personally, 
 I'd also like a REPL command which prints out a list of all of the objects 
 currently in memory space (like 'whos' in Octave). This seems like a basic 
 requirement for REPL based numerical programming.

 Julia is elegant and growing strongly, but I'm still quite selective 
 about who I proselytise to. I have the feeling that it will be so many 
 times a more comfortable experience in 6-12 months time that I'd rather 
 not 
 colour people's early experiences in a negative light if better is soon to 
 come.

 David.

Re: [julia-users] Re: Getting people to switch to Julia - tales of no(?) success

[David Higgins]

:D I suck! 

On Thursday, 5 March 2015 15:14:59 UTC+1, Ivar Nesje wrote:

  I'd also like a REPL command which prints out a list of all of the 
 objects currently in memory space (like 'whos' in Octave)

 I'd recommend you try the obscurely named whos() in Julia :)

 torsdag 5. mars 2015 14.38.05 UTC+1 skrev David Higgins følgende:

 Oh, and an IDE is the other requirement of my hard core programming 
 brethren. The debugger is higher on their list of priorities, but the IDE 
 is also vital (and one capable of handling projects, etc. we do large scale 
 numerical projects).

 David.

 On Thursday, 5 March 2015 14:35:23 UTC+1, David Higgins wrote:

 I agree with many of the comments above. I recommend Julia only to a 
 subset of my colleagues. From Matlab the barrier to entry is incredibly low 
 and you gain on both speed and price, the only argument against is that 
 Matlab users tend to have years of experience in their one language and not 
 such a habit of learning new languages.

 I personally moved from mainly GPGPU based programming using C; despite 
 the difficulty of that field I found the move painful due to a lack of 
 detailed documentation (my perception). Don't get me wrong, there's enough 
 documentation out there to make a decent stab at getting things done. But 
 I'm used to having a much more nuanced understanding of a language and the 
 documentation doesn't yet go into this level of detail, nor are there 
 sufficient examples out there.

 For my colleagues who are strong programmers (Python particularly), they 
 refuse to touch the language until there's a debugger. At the very least 
 they want to be able to set breakpoints and run to them. Personally, I'd 
 also like a REPL command which prints out a list of all of the objects 
 currently in memory space (like 'whos' in Octave). This seems like a basic 
 requirement for REPL based numerical programming.

 Julia is elegant and growing strongly, but I'm still quite selective 
 about who I proselytise to. I have the feeling that it will be so many 
 times a more comfortable experience in 6-12 months time that I'd rather not 
 colour people's early experiences in a negative light if better is soon to 
 come.

 David.

Re: [julia-users] Re: Getting people to switch to Julia - tales of no(?) success

[David Higgins]

I agree with many of the comments above. I recommend Julia only to a subset 
of my colleagues. From Matlab the barrier to entry is incredibly low and 
you gain on both speed and price, the only argument against is that Matlab 
users tend to have years of experience in their one language and not such a 
habit of learning new languages.

I personally moved from mainly GPGPU based programming using C; despite the 
difficulty of that field I found the move painful due to a lack of detailed 
documentation (my perception). Don't get me wrong, there's enough 
documentation out there to make a decent stab at getting things done. But 
I'm used to having a much more nuanced understanding of a language and the 
documentation doesn't yet go into this level of detail, nor are there 
sufficient examples out there.

For my colleagues who are strong programmers (Python particularly), they 
refuse to touch the language until there's a debugger. At the very least 
they want to be able to set breakpoints and run to them. Personally, I'd 
also like a REPL command which prints out a list of all of the objects 
currently in memory space (like 'whos' in Octave). This seems like a basic 
requirement for REPL based numerical programming.

Julia is elegant and growing strongly, but I'm still quite selective about 
who I proselytise to. I have the feeling that it will be so many times a 
more comfortable experience in 6-12 months time that I'd rather not colour 
people's early experiences in a negative light if better is soon to come.

David.

On Thursday, 5 March 2015 13:43:51 UTC+1, Christoph Ortner wrote:

 For this reason, while I am happy to talk about how nice Julia is, I
 will not try to convince people to switch to it. IMO the people who are
 potential switchers at this stage have already looked at Julia, and
 evangelizing more aggressively could be counterproductive at this stage.


 I think this is really important. Personally, I am thrilled with Julia, 
 because I write code that does not need any packages other than plotting 
 and File I/O. But I really need the combination of rapid development 
 (scripting, dynamic) and then being able to optimise certain passages, 
 without ever having to switch to C.  But I would never recommend Julia 
 (at this stage) to a production user, only to people who might like to 
 play with it. 

 The main point I make to people is that the entry barrier from Matlab to 
 Julia is incredibly low. (Whereas from Matlab to Python it is huge.) The 
 only real hurdle for Matlab people, I think, is to get used to multiple 
 dispatch, that took me a while, but I am now in a constant state of bliss 
 :).

 So far, I've convinced my entire research group, three collaborators and a 
 friend's postdoc to try out Julia both for research and teaching, and the 
 response I got from everyone so far has been very positive. We are all 
 numerical analysts, or related disciplines, and for us it is just a 
 wonderful language.

 Christoph

Re: [julia-users] Re: Getting people to switch to Julia - tales of no(?) success

[David Higgins]

Oh, and an IDE is the other requirement of my hard core programming 
brethren. The debugger is higher on their list of priorities, but the IDE 
is also vital (and one capable of handling projects, etc. we do large scale 
numerical projects).

David.

On Thursday, 5 March 2015 14:35:23 UTC+1, David Higgins wrote:

 I agree with many of the comments above. I recommend Julia only to a 
 subset of my colleagues. From Matlab the barrier to entry is incredibly low 
 and you gain on both speed and price, the only argument against is that 
 Matlab users tend to have years of experience in their one language and not 
 such a habit of learning new languages.

 I personally moved from mainly GPGPU based programming using C; despite 
 the difficulty of that field I found the move painful due to a lack of 
 detailed documentation (my perception). Don't get me wrong, there's enough 
 documentation out there to make a decent stab at getting things done. But 
 I'm used to having a much more nuanced understanding of a language and the 
 documentation doesn't yet go into this level of detail, nor are there 
 sufficient examples out there.

 For my colleagues who are strong programmers (Python particularly), they 
 refuse to touch the language until there's a debugger. At the very least 
 they want to be able to set breakpoints and run to them. Personally, I'd 
 also like a REPL command which prints out a list of all of the objects 
 currently in memory space (like 'whos' in Octave). This seems like a basic 
 requirement for REPL based numerical programming.

 Julia is elegant and growing strongly, but I'm still quite selective about 
 who I proselytise to. I have the feeling that it will be so many times a 
 more comfortable experience in 6-12 months time that I'd rather not colour 
 people's early experiences in a negative light if better is soon to come.

 David.

[julia-users] Re: Julia users Berlin

[David Higgins]

Hi all,

Alex: I'm not around on those dates, but you should definitely go ahead and 
meet up there!

I was thinking of probably using Meet-up to try to organise a Users Group 
meeting. Does anyone know of any other site which offers similar 
functionality? (for free??)

I'm particularly interested in meeting existing users to hear how they use 
the language. With every new programming language you learn there are a 
bunch of bad habits you initially develop in your programming. I'm hoping 
to use this interaction to remove them from my Julia coding. Also, I'd like 
exposure to the wider Julia Libraries which I don't encounter in my daily 
work.

David.

On Tuesday, 3 March 2015 12:31:06 UTC+1, Alex wrote:

 Hi together,

 As you might know the Spring Meeting of the German Physical Society is 
 held in Berlin from 15/03 to 20/03. Maybe this would be an opportunity to 
 have a (small) Julia meeting/get-together of some sort? There certainly 
 must be some Julians among the ~6k participants ...

 Best,

 Alex.

[julia-users] Re: Julia users Berlin

[David Higgins]

Hans,

I'm definitely tempted but I want to gauge the interest here first. So far 
we have only two of us reporting as being in Berlin and two who will be in 
town occasionally. There are git commits coming from Berlin on the map of 
Julia commits one of the MIT guys posted a few days ago, but those are 
based upon self reported github location (I think mine puts me in Chicago).

David.

On Thursday, 26 February 2015 19:35:38 UTC+1, Hans W Borchers wrote:

 David,

 why don't you just set up a Julia Meetup group. This will make it much 
 easier 
 to organize meetings and to keep interested participants informed.
 I guess in Europe there are Julia Meetups in London and Zürich only, and it
 would be nice to have Berlin come in next.


 On Wednesday, February 25, 2015 at 2:35:13 PM UTC+1, David Higgins wrote:

 Hi all,

 I'm based at the Technical University in Berlin and I've more or less 
 completed the transition to using Julia for all of my research (I still use 
 OpenCL for bigger projects). I'm just wondering if there are other Berlin 
 based Julia users/developers who want to meet up from time to time to share 
 tips, etc.

 David.

[julia-users] Julia users Berlin

[David Higgins]

Hi all,

I'm based at the Technical University in Berlin and I've more or less 
completed the transition to using Julia for all of my research (I still use 
OpenCL for bigger projects). I'm just wondering if there are other Berlin 
based Julia users/developers who want to meet up from time to time to share 
tips, etc.

David.

Re: [julia-users] Pass by reference

[David Higgins]

Thanks Stefan! That really helps.

I don't know if you guys have such a thing as a language specification 
document (I'm guessing the language is too much in evolution at present for 
that to be the case), but if you do I'd be happy to work towards porting 
bits of it to the main documentation.

David.

On Tuesday, 17 February 2015 18:41:35 UTC+1, Stefan Karpinski wrote:

 The confusion stems from this: *assignment and mutation are not the same 
 thing.*

 *Assignment. *Assignment looks like `x = ...` – what's left of the `=` is 
 a variable name.

 Assignment changes which object the variable `x` refers to (this is called 
 a variable binding). It doesn't mutate any objects at all.

 *Mutation.* There are two typical ways to mutate something in Julia:

- `x.f = ...` – what's left of the `=` is a field access expression;
- `x[i] = ...` – what's left of the `=` is an indexing expression.

 Currently, field mutation is fundamental – that syntax can *only* mean 
 that you are mutating a structure by changing its field. This may change 
 https://github.com/JuliaLang/julia/issues/1974 - private 
 https://github.com/JuliaLang/julia/issues/1974. Array mutation syntax 
 is not fundamental – `x[i] = y` means `setindex!(x, y, i)` and you can 
 either add methods to setindex! or locally change which generic function 
 `setindex!`. Actual array assignment is a builtin – a function implemented 
 in C (and for which we know how to generate corresponding LLVM code).

 Mutation changes the values of objects; it doesn't change any variable 
 bindings. After doing either of the above, the variable `x` still refers to 
 the same object it did before; that object may have different contents, 
 however. In particular, if that object is accessible from some other scope 
 – say the function that called one doing the mutation – then the changed 
 value will be visible there. But no bindings have changed – all bindings in 
 all scopes still refer to the same objects.

 You'll note that in this explanation I never once talked about mutability 
 or immutability. That's because it has nothing to do with any of this – 
 mutable and immutable objects have exactly the same semantics when it comes 
 to assignment, argument passing, etc. The only difference is that if you 
 try to do `x.f = ...` when x is immutable, you will get a runtime error.

 Maybe we should put this explanation in the manual somewhere. If someone 
 wants to make a pull request doing that, you can use any of my text here.

 On Tue, Feb 17, 2015 at 11:59 AM, David Higgins daithio...@gmail.com 
 javascript: wrote:

 Thanks Stefan,

 I did actually see these. I was partly raising this as a didactic point 
 as the discussion group site is searchable. I think that my main suggestion 
 would be that a section on which types are Mutable and which types are 
 Immutable be added to the Types documentation page (and that a relevant 
 comment also be added to the pages Variables, Integers and 
 Floating-point numbers, etc.) While I occasionally find passing comment to 
 specific types being mutable (eg. arrays), I haven't yet found a tableau of 
 different types and their mutability status nor a statement that when in 
 doubt assume it's immutable (which would probably be a dangerous 
 assumption, right?).

 I don't know how you feel about it, but I figure that raising issues like 
 this on the discussion forum allows for the documentation to evolve to a 
 state where there are a lot less newbie questions eventually.

 David.

 On Tuesday, 17 February 2015 17:41:45 UTC+1, Stefan Karpinski wrote:

 See:

 http://julia.readthedocs.org/en/latest/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
  - private 
 http://julia.readthedocs.org/en/latest/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
  - private 
 http://julia.readthedocs.org/en/latest/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
  - private 
 http://julia.readthedocs.org/en/latest/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://julia.readthedocs.org/en/latest/manual/faq/#why-
 does-x-y-allocate-memory-when-x-and-y-are-arrays - private 
 http://julia.readthedocs.org/en/latest/manual/faq/#why-does-x-y-allocate-memory-when-x-and-y-are-arrays
  - private 
 http://julia.readthedocs.org/en/latest/manual/faq/#why-does-x-y-allocate-memory-when-x-and-y-are-arrays
  - private 
 http://julia.readthedocs.org/en/latest/manual/faq/#why-does-x-y-allocate-memory-when-x-and-y-are-arrays


 On Tue, Feb 17, 2015 at 10:54 AM, David Higgins daithio...@gmail.com 
 wrote:


 In Julia, all arguments to functions are passed by reference.


 Is this really true

Re: [julia-users] Re: Locality of variables (loops)

[David Higgins]

To be honest, I'm ok with Stefan's response. My problem was based on a 
mistake on my part (I didn't realise that I had $i declared outside of the 
loops; I thought I'd opened a new julia instance) and an expectation for C 
style looping rather than Python style (ie 'for' \equiv 'let').

Since Julia can expect more people from my C-based background, I would 
suggest that this be highlighted in the, rapidly evolving, manual. I would 
also argue for a devoted article on variable scope in the manual in the 
long run. I am quite comfortable with the decisions you've made in 
designing the language, but they are contrary to what we are used to from 
many other languages. And while the inability to write to a global variable 
from within a function in the absence of a global declaration is 
numerically very sound it leads to a whole new set of potential programming 
errors.

David.

On Sunday, 8 February 2015 10:27:41 UTC+1, Mauro wrote:

  Even more commonly, I want to know (and use) the value of the iteration 
  variable at the iteration that threw an error.  Debugging errors in 
 loops 
  would be more difficult without this ability. 

 But that only works in the global scope in the REPL, right?  So that is 
 a pretty limited use, and hopefully there will be a debugger available 
 soon.  And it could be worked around with one additional line: 

 for i=1:n 
 ii=i 
 do_something 
 end 

 Another pro-argument: This change would mean that all the scope-blocks 
 which introduce a binding in their head (function, let, for) make it 
 local to the block. 

[julia-users] Re: Locality of variables (loops)

[David Higgins]

I need to make one correction. I've just realised that you need to declare 
i and j before the loops for some of my complaints to hold.

On Friday, 6 February 2015 12:25:34 UTC+1, David Higgins wrote:

 I have a use case I found interesting. I guess it's well known to some of 
 you, but I never noticed it in the documentation and I find it 
 counterintuitive, both as an experienced programmer and with respect to the 
 typical scope rules of variables in Julia.

 I accidentally nested a loop within another loop using the same index 
 variable for both loops. First of all, there are reasons sometimes you'd 
 want to do this but I did it by accident as a typo. But the scope rules of 
 variables for Julia, as applied to functions, state that you can read a 
 variable value at a lower level in the hierarchy but you cannot write to it 
 so I actually assumed that this also applied to loops (*first mistake*).

 Secondly, as you'll see if you execute the simplified example of what I 
 actually did here:
 for i = 1:5
   for j = 1:5
 for i = 1:3
   print(tick );
 end
   print( $i\n);
   end
 print( $j $i\n);

 Julia still knew to only run the outer loop 5 times, despite the fact that 
 I was setting the variable bound to $i at level 2 to the value 3 at level 3 
 in the nested hierarchy of loops. I suspect that I can see what's happening 
 at the compiler/interpretter level, but I do think that this is confusing.

 We seem to have the worst of both worlds here in that we can access and 
 change $i at an inner loop level and have the change be persistent, but yet 
 we cannot change the behaviour of the outer loop (as would be the case in 
 C).

 What do you guys think? Can this be clarified in the documentation, or 
 should the actual behaviour of julia be modified?

 David.

[julia-users] Locality of variables (loops)

[David Higgins]

I have a use case I found interesting. I guess it's well known to some of 
you, but I never noticed it in the documentation and I find it 
counterintuitive, both as an experienced programmer and with respect to the 
typical scope rules of variables in Julia.

I accidentally nested a loop within another loop using the same index 
variable for both loops. First of all, there are reasons sometimes you'd 
want to do this but I did it by accident as a typo. But the scope rules of 
variables for Julia, as applied to functions, state that you can read a 
variable value at a lower level in the hierarchy but you cannot write to it 
so I actually assumed that this also applied to loops (*first mistake*).

Secondly, as you'll see if you execute the simplified example of what I 
actually did here:
for i = 1:5
  for j = 1:5
for i = 1:3
  print(tick );
end
  print( $i\n);
  end
print( $j $i\n);

Julia still knew to only run the outer loop 5 times, despite the fact that 
I was setting the variable bound to $i at level 2 to the value 3 at level 3 
in the nested hierarchy of loops. I suspect that I can see what's happening 
at the compiler/interpretter level, but I do think that this is confusing.

We seem to have the worst of both worlds here in that we can access and 
change $i at an inner loop level and have the change be persistent, but yet 
we cannot change the behaviour of the outer loop (as would be the case in 
C).

What do you guys think? Can this be clarified in the documentation, or 
should the actual behaviour of julia be modified?

David.

[julia-users] Re: Locality of variables (loops)

[David Higgins]

So all of this seems to be a result of the for loop basically using a 
range/array type variable on the right hand side of the loop variable. So 
even if I change the value of the iterator variable within the loop I 
cannot change the array over which I am looping (anyone used to Python will 
find this natural, I'm more used to C).

I guess everything is consistent now.

David

On Friday, 6 February 2015 12:25:34 UTC+1, David Higgins wrote:

 I have a use case I found interesting. I guess it's well known to some of 
 you, but I never noticed it in the documentation and I find it 
 counterintuitive, both as an experienced programmer and with respect to the 
 typical scope rules of variables in Julia.

 I accidentally nested a loop within another loop using the same index 
 variable for both loops. First of all, there are reasons sometimes you'd 
 want to do this but I did it by accident as a typo. But the scope rules of 
 variables for Julia, as applied to functions, state that you can read a 
 variable value at a lower level in the hierarchy but you cannot write to it 
 so I actually assumed that this also applied to loops (*first mistake*).

 Secondly, as you'll see if you execute the simplified example of what I 
 actually did here:
 for i = 1:5
   for j = 1:5
 for i = 1:3
   print(tick );
 end
   print( $i\n);
   end
 print( $j $i\n);

 Julia still knew to only run the outer loop 5 times, despite the fact that 
 I was setting the variable bound to $i at level 2 to the value 3 at level 3 
 in the nested hierarchy of loops. I suspect that I can see what's happening 
 at the compiler/interpretter level, but I do think that this is confusing.

 We seem to have the worst of both worlds here in that we can access and 
 change $i at an inner loop level and have the change be persistent, but yet 
 we cannot change the behaviour of the outer loop (as would be the case in 
 C).

 What do you guys think? Can this be clarified in the documentation, or 
 should the actual behaviour of julia be modified?

 David.

[julia-users] Re: Great new expository article about Julia by the core developers

[David Higgins]

So how does one go about getting an invitation to JuliaBox? It's referenced 
in the article but you need an invitation to login

Dave.

On Saturday, 8 November 2014 22:58:31 UTC, Peter Simon wrote:

 Just found this great new highly accessible exposition about the Julia 
 language: http://arxiv.org/pdf/1411.1607v1.pdf, by Jeff et al.  It's the 
 perfect into to share with many of my not-yet-Julian colleagues.

 --Peter

[julia-users] JuliaBox

[David Higgins]

Hi,

Does anyone if JuliaBox http://www.juliabox.org is open to applications 
to use it these days? I came across it in the ArXiV paper about Julia 
mentioned here 
https://groups.google.com/d/msg/julia-users/DtjfcslGcMw/s-QBbFnelugJ. I'm 
a current Julia user but I have a number of colleagues who would be 
interested in a sandboxed, non-install version to play with before making 
the jump to installation. I made the mistake of suggesting JuliaBox before 
verifying that it was possible to create an account, it seems it's invite 
only for now.

Thanks,
Dave.

Re: [julia-users] JuliaBox

[David Higgins]

Thanks Ivar.

5 people Shashi, all academics so I'd like to get them interested.

Dave.

On Monday, 10 November 2014 19:31:17 UTC, Shashi Gowda wrote:

 Hello David,

 Sorry about that. You can use the invite code G01014. How many others do 
 you want to invite? A handful should be fine. Just do not publish it online.

 Thank you

 On Tue, Nov 11, 2014 at 12:15 AM, David Higgins daithio...@gmail.com 
 javascript: wrote:

 Hi,

 Does anyone if JuliaBox http://www.juliabox.org is open to 
 applications to use it these days? I came across it in the ArXiV paper 
 about Julia mentioned here 
 https://groups.google.com/d/msg/julia-users/DtjfcslGcMw/s-QBbFnelugJ. 
 I'm a current Julia user but I have a number of colleagues who would be 
 interested in a sandboxed, non-install version to play with before making 
 the jump to installation. I made the mistake of suggesting JuliaBox before 
 verifying that it was possible to create an account, it seems it's invite 
 only for now.

 Thanks,
 Dave.

Re: [julia-users] JuliaBox

[David Higgins]

On Monday, 10 November 2014 19:33:09 UTC, Shashi Gowda wrote:


 On Tue, Nov 11, 2014 at 1:01 AM, Shashi Gowda shashi...@gmail.com 
 javascript: wrote:


 Just do not publish it online.


 Oops I meant to send it to David directly. If anyone else wants a code, 
 please let me know.


I did wonder about this bit :P

Thank you very much in any case.

Dave 

Re: [julia-users] Vectorised boolean access to array elements

[David Higgins]

Thanks guys. I didn't think of using the dot.

David.

On Friday, 15 August 2014 18:53:43 UTC+2, Patrick O'Leary wrote:

 Because that might be subtle to see if you're not looking closely, and you 
 mentioned a MATLAB background, note that there is an additional dot before 
 the comparison operator--Julia uses the elementwise operator notation for 
 comparison operators as well as for elementwise multiplication and 
 division. Unlike their primitive arithmetical counterparts, though, that 
 notation is mandatory for comparison operators even when one argument is 
 scalar.

 On Friday, August 15, 2014 9:01:57 AM UTC-5, John Myles White wrote:

 a . 5 


 On Aug 15, 2014, at 3:53 AM, David Higgins daithio...@gmail.com 
 javascript: wrote: 

  Hi, 
  
  Is there a mechanism for vectorised logical access to array elements in 
 Julia? I basically mean, is there an equivalent to the Matlab notation 
  a[a5] 
  which should give all of the elements of a[] which have value less than 
 5. 
  
  I guess the feature I've not found is the ability to create the boolean 
 index vector 'a5'. I'm doing it with loops at present. 
  
  Thanks, 
  David. 
  

[julia-users] Vectorised boolean access to array elements

[David Higgins]

Hi,

Is there a mechanism for vectorised logical access to array elements in 
Julia? I basically mean, is there an equivalent to the Matlab notation
a[a5]
which should give all of the elements of a[] which have value less than 5.

I guess the feature I've not found is the ability to create the boolean 
index vector 'a5'. I'm doing it with loops at present.

Thanks,
David.