[#396148] Facebook Group — Moses Aronov <mosesaro@...>

There is a facebook group that was recently created so we could all communicate with other fellow developers

13 messages 2012/06/05
[#396178] Re: Facebook Group — Chad Perrin <code@...> 2012/06/06

On Wed, Jun 06, 2012 at 01:55:48AM +0900, Moses Aronov wrote:

[#396186] Inexplicable Argument Error — Doug Jolley <lists@...>

I am encountering a very strange argument error. I simplified my code

12 messages 2012/06/06

[#396229] Thread#kill is not rescued by "rescue Exception" — Iñaki Baz Castillo <ibc@...>

Hi, let me show this easy code:

13 messages 2012/06/07

[#396333] Is "a,b=c,d" atomic? or do I need a Mutex? — Iñaki Baz Castillo <ibc@...>

Hi, I have two methods that could be called by different threads and

10 messages 2012/06/10

[#396357] ffi - Popping image on top of the screen — "Damián M. González" <lists@...>

Ey guys, how are you? I`m developing an application in Ruby, using

12 messages 2012/06/11

[#396373] Why should I learn ruby? — Kasper Steensig <lists@...>

I have wondered whether I should learn ruby or python hence they are

16 messages 2012/06/11

[#396503] Syntax Highlighter — Intransition <transfire@...>

Would you agree that Ruby shouldn't lack for a syntax highlighting library

18 messages 2012/06/14

[#396589] Unsubcripe — Suresh Rajkumar <sureshrajchennai@...>

Unsubcipe my mail address from the group.

13 messages 2012/06/18

[#396615] Symbols and Strings... — Hal Fulton <rubyhacker@...>

Hello, all...

29 messages 2012/06/18
[#396620] Re: Symbols and Strings... — Eric Hodel <drbrain@...7.net> 2012/06/18

On Jun 18, 2012, at 15:09, Hal Fulton wrote:

[#396641] Re: Symbols and Strings... — Robert Klemme <shortcutter@...> 2012/06/19

On Tue, Jun 19, 2012 at 12:31 AM, Eric Hodel <drbrain@segment7.net> wrote:

[#396643] Re: Symbols and Strings... — Hal Fulton <rubyhacker@...> 2012/06/19

Personally, I don't have a problem with "reducing the contract"

[#396646] Re: Symbols and Strings... — Robert Klemme <shortcutter@...> 2012/06/19

On Tue, Jun 19, 2012 at 5:17 PM, Hal Fulton <rubyhacker@gmail.com> wrote:

[#396659] Re: Symbols and Strings... — Hal Fulton <rubyhacker@...> 2012/06/19

> > Freezing an object also reduces its contract.

[#396678] Re: Symbols and Strings... — Robert Klemme <shortcutter@...> 2012/06/20

On Tue, Jun 19, 2012 at 10:12 PM, Hal Fulton <rubyhacker@gmail.com> wrote:

[#396701] Re: Symbols and Strings... — Henry Maddocks <hmaddocks@...> 2012/06/20

[#396702] Re: Symbols and Strings... — Bartosz Dziewoński <matma.rex@...> 2012/06/20

2012/6/20 Henry Maddocks <hmaddocks@me.com>:

[#396703] Re: Symbols and Strings... — Henry Maddocks <hmaddocks@...> 2012/06/20

[#396710] Re: Symbols and Strings... — Jeremy Bopp <jeremy@...> 2012/06/20

On 06/20/2012 03:58 PM, Henry Maddocks wrote:

[#396627] Does ERB have recursive template support? — Todd Wei <lists@...>

I want to use ERB template library to do some code generation. It

10 messages 2012/06/19

[#396649] Looking for a better way to add a method to a core class than monkey patching — Iain Barnett <iainspeed@...>

Hi all,

17 messages 2012/06/19
[#396670] Re: Looking for a better way to add a method to a core class than monkey patching — Avdi Grimm <groups@...> 2012/06/20

Please do not monkey patch core libraries in gems, unless the *purpose* of

[#396685] Benchmark obsession? — "Jan E." <lists@...>

Hi,

23 messages 2012/06/20
[#396709] Re: Benchmark obsession? — Ryan Davis <ryand-ruby@...> 2012/06/20

[#396815] Array#sample is Set#sample and not Array#sample ! — Michel Demazure <lists@...>

Arrays are ordered, sets are not. Sampling an array should give random

11 messages 2012/06/25

[#396877] CSV.open problem, help please — Kaye Ng <lists@...>

This code doesn't seem to work

21 messages 2012/06/27

[#396896] Copying text from MS Word and wrapping in HTML - help please — Adam Holloway <lists@...>

Hi,

11 messages 2012/06/27

[#396966] Interactions between 'new' and 'initialize' ? — Cees Zeelenberg <lists@...>

In JRuby, I am extending an existing Java Class with a Ruby initialising

9 messages 2012/06/28

[#396975] stack level too deep for quicksort code — bei zhao <lists@...>

Hi, below is my quicksort implementation in ruby(using the first element

12 messages 2012/06/28

[#396996] Accessor Methods with a Twist — Doug Jolley <lists@...>

I am surprised that the code shown below returns, 'Doug'. I would

15 messages 2012/06/29

[#397001] ruby performance — anaray anaray <lists@...>

Hi,

33 messages 2012/06/29
[#397007] Re: ruby performance — Bartosz Dziewoński <matma.rex@...> 2012/06/29

The MRI is, unfortunately, slow as balls, and there's not much you can

[#397008] Re: ruby performance — Hans Mackowiak <lists@...> 2012/06/29

Bartosz Dziewoナгki wrote in post #1066673:

[#397010] Re: ruby performance — Bartosz Dziewoński <matma.rex@...> 2012/06/29

2012/6/29 Hans Mackowiak <lists@ruby-forum.com>:

[#397011] Re: ruby performance — Bartosz Dziewoński <matma.rex@...> 2012/06/29

2012/6/29 Hans Mackowiak <lists@ruby-forum.com>:

[#397047] Re: ruby performance — "Andreas S." <lists@...> 2012/07/01

Bartosz Dziewoński wrote in post #1066681:

[#397048] Re: ruby performance — Bartosz Dziewoński <matma.rex@...> 2012/07/01

2012/7/1 Andreas S. <lists@ruby-forum.com>:

[#397068] Re: ruby performance — Robert Klemme <shortcutter@...> 2012/07/02

On Sun, Jul 1, 2012 at 1:42 PM, Bartosz Dziewoナгki <matma.rex@gmail.com> wrote:

[#397086] Re: ruby performance — Dan Connelly <lists@...> 2012/07/02

Here's my contribution:

Re: ruby performance

From: Bob Hutchison <hutch-lists@...>
Date: 2012-06-30 15:41:21 UTC
List: ruby-talk #397027
On 2012-06-29, at 1:13 PM, anaray anaray wrote:

> Hi,
> 
> I have snippet from my project, and this iteration is performing very
> very badly compared to same implementation in Java
> 
> Java : Time Elapsed in milliseconds: 8109 ms.
> Ruby : Time Elapsed in Seconds: 132.28125 sec.
> 
> It a huge difference, Am i missing something here, is there any
> particular best practices.

Yes that's a huge difference, and what you're seeing is roughly what you have to expect. Count on 10-20 times slower unless you are heavily reliant on stuff Java can't do well (like start up times, or fall back on underlying C code as some gems do). Ruby can also be a big help if you have memory constraints.

You might consider JRuby because it sounds as though the JVM is something you're familiar with, but also because you can take advantage of multi-core architectures if your algorithms are parallelisable. But it's a trade off in that some gems won't work in JRuby.

You might also consider coding parts of your program in C. Yeah, I know. This is probably the *last* thing you want to do :-)

>  I am trying to implement Ruby for a
> particular project, where it needs to read/process huge arrays etc
> Please guide me.

In general there's not much more to say. But if you get into specifics, maybe. However, most of the suggestions we could make will apply to a Java version as well, so you aren't necessarily going to see a relative performance increase, maybe, if lucky an absolute performance increase.

> 
> input = "ababaa" * 10000
> suffix_array = input.split(//)

Is that really what you mean?

> suffix_array_len = suffix_array.size
> 
> for i in 1..suffix_array_len-1 do

Are you starting at 1 for a reason? The first index is 0.

I'd probably write this something like:

(0...l).each do | i |

The '0...l' is the same as 0..(l-1)

>  total=0
>  for j in i..suffix_array_len-1 do
> 
>  end
> end


Cheers,
Bob

> 
> -- 
> Posted via http://www.ruby-forum.com/.
> 

----
Bob Hutchison
Recursive Design Inc.
http://www.recursive.ca/
weblog: http://xampl.com/so





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