Where can I find math intense apps in Ruby - ruby

I have found many rails apps mainly on the enterprise, social networking kind of web apps. I see that Ruby is compared with some of the great OOPS languages like Java & C# but I am really finding it hard to get some Math Intense apps. Any knowledgeble input (links to sample programs etc.), where the usage of the language is shown with ease and is like jumpstart or show how the language can be used for variety of math probs, is greatly appreciated.

Unfortunately, Ruby hasn't ventured very far into mathematical and scientific computing. Currently, there is a pre-alpha library called SciRuby that is attempting to bring more math oriented capabilities to Ruby. They are trying to build a NumPy/SciPy equivalent. A few projects that are under SciRuby with example usage are:
NMatrix
Rubyvis
Statsample
Each project has various examples on how to get started/contribute. A good place to start is their docs and their mailing list.
Hope that helps.

Related

Python 3.x website and app GUI

I am only starting out to learn programming, currently on Python 3.2, and was looking to build a few simple applications and possibly website(s), also simple. I want to know a good GUI library to start that:
is simple with good control (not a major issue, I'm planning to advance as much as possible anyway);
is cross-platform, with a native feel;
has good tutorials somewhere (please post link);
I can use to sell applications/make profit from websites with little to no licensing issues (a must);
can use Chinese characters as strings (not a must, but would definitely be a game changer).
Thanks a lot!
There are two main options for cross platform GUIs in Python 3:
Tkinter is simple and ships with Python, but applications can look a bit ugly. I like this site for learning it, although it's a bit old.
Qt is bigger and more complex, but produces powerful, good looking applications. If you want to make proprietary software with it, you'll need to use PySide, rather than PyQt, but how you use them is almost identical. There are plenty of tutorials online (mainly for PyQt, which has been around longer, but they're fine if you're using PySide).
Both should handle any characters, including Mandarin, so long as the system has fonts with those characters to display them.
Most of the tutorials for both will be based on Python 2, so you'll have to make a few changes. print "foo" becomes print("foo"), and Tkinter becomes tkinter, for example.

What are those tutorial shells?

What are the code tutorial shells called that are used on various websites such as codecademy, codeschool, mongo db, try ruby etc.
Is there a service for building and maintaining these things? Or is it something you build yourself?
I found ShellInABox but it doesn't seem exactly like the only one people are using?
These are colloquially known as "web REPLs" (a term meaning "Read/Eval/Print Loop").
They can be distinguished by unrestricted ones used for debugging by describing them as "sandboxed". There is not a single, universal toolkit used to build these, though you may find repl.it (which uses a number of interpreters compiled to javascript to run client-side REPLs for numerous languages) interesting.

Best practices for internationalization using PyQt4

I want to add multiple language support to my application which is written in Python using PyQt4. I was looking for information on how to add multiple languages and would like to see how other people do this.
Here i read:
The PyQt behaviour is unsatisfactory and may be changed in the future.
It is recommended that QCoreApplication.translate() be used in
preference to tr() (and trUtf8()). This is guaranteed to work with
current and future versions of PyQt and makes it much easier to share
message files between Python and C++ code.
In files generated by pyuic4 i see something like:
WPopupCalendar.setWindowTitle(QtGui.QApplication.translate("WPopupCalendar", "Календарь", None, QtGui.QApplication.UnicodeUTF8))
This looks too long for me. I was thinking to make my own tr helper function which somehow would automate the process.
Also i could not find articles describing a workflow and specifics for developing multilingual apps in python with pyqt4.
Would you please advice me with some good and convenient techniques on this?
Just use tr (or trUtf8) everywhere to start with. Only bother with translate when you identify code that is affected by the issue with multiple inheritance (which could easily be never).
I would suggest you have a look at Qt's i18n overview, and the Qt Linguist Manual. They are obviously both oriented towards C++ projects, but it should give you a pretty clear idea of what's required.
For a working example, you could also download the source code of the Eric Python IDE - it's written in PyQt4, and has support for a half dozen or more languages.

Which programming languages meet these criteria for GUI app development? [closed]

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I'm trying to find a programming language I feel really comfortable learning and using for desktop/GUI application development. I realize it's unlikely that any language meets ALL of these criteria, but I'd like to find one that meets as many as possible. I've listed the following features ROUGHLY in order from most desirable/important to least.
Ideal Language Features:
Code Style: C/Java-like
GUI Development: Easy, elegant, and platform-Native styling
Community: Widely documented, active development, friendly & helpful, unity of focus
Object-oriented
Garbage Collection, no worrying about pointers, etc
Native compilation, NO 3rd-party runtimes like GTK or .NET
Multi-platform (can be compiled on *nix, Windows, Mac)
Reasonably fast
Mixed typing (soft-typed, OR both soft- and strict-typed -- i.e. Pike)
Background:
Most importantly, I need something that is straight foward and reasonably familiar, and something that isn't going to require a deep understanding of platform-specific APIs. I can't afford to spend a lot of time learning to develop Win32 apps in C++ for example. I've used wxWidgets, and liked the basic usage, but I'm really wanting to use a language with garbage collection, dynamic typing, and so on.
My frustration with Java, C#, and others is the need for a 3rd party runtime. I don't want end users to have to worry about installing and maintaining a separate platform.
Now then. Ideas??
Haha, due to the constraints you imposed you are now left with HTML and javascript. Good luck :)
The answer to your question is simply: None.
You excluded all desirable languages and platforms in your question.
I'd suggest you throw away your aversion against .NET and go with Delphi Prism. It's not C#, it is cross-platform compatible (everything is officially supported on Mono) and you can create applications that bring the runtime with them (Mono as part of your application).
I'd suggest Groovy and Griffon. Groovy is a dynamic language (like Ruby / Python) that runs on the JVM and integrates with millions of Java libraries out there easily. Griffon is a high-productivity RAILS-like framework for developing GUIs. Groovy has been around for 5 years and has a robust community and is supported by SpringSource (now division of VMWare). Griffon is a bit younger, but also has a fairly robust community.
These seem to fit your criteria.
I know I switched from Java to Grails (web framework written in Groovy that's similar to Rails), and haven't looked back.
Have you looked at QT? It's a really great GUI library and there are bindings for just about every language in common usage. There is a ton of documentation and a wide community. You mention that you want to do something in a language with garbage collection and dynamic typing, but rule out Python and Ruby, which are the 2 most popular languages that fit this criteria (also, they both have great QT bindings, I use pyQT4 and it is just awesome). They really aren't that far from what you do in Java/C, you just end up writing a lot less.
Wow you really limit your choices. I'm going to jump on the QT bandwagon and recommend C++.
Most of the objects in QT inherit from another object that sort of does it's own garbage collection.
There is incredible documentation out there for it.
QT is extremely powerful and has most of the elements you would like, and is extensible if you want to modify elements yourself.
If you do a static build for your release build the people you give the application to won't need distribute any other libraries as they will all be built into the .exe file.
The next iteration of Delphi is said to be cross-platform (Windows, Mac, Linux). I think it meets all your requirements except garbage collection.
No language meets all of those restrictions. Technically, it sounds like you're asking for something almost identical to Java but then explicitly disallow Java for unstated reasons. Conceptually, it sounds like you're looking for Python or Ruby but disallow them for using slightly different syntax.
Given the order of priorities, I think the closest you'll find in existing languages might be C with the Boehm GC and GTK+ for the GUI (and GLib for the object system). You do say "No GTK" under "No third-party runtime required", but I'm not sure what "runtime" you refer to here, since IIRC it's just a bunch of C libraries.
Given the specificity of the requirements, I think your best bet is to write your own language. Compilers really aren't that hard to write anymore. There are off-the-shelf tools to help with parsing and code generation and math and text processing and GC and so on. Once you get started you'll probably find people willing to help port it. Many existing cross-platform GUI libraries (like wxWidgets) use C/C++ so if you have a decent FFI you can use that, too. You want "support" and "documented" but if you're the primary author you'll understand it better than anybody. The hardest part about a language is design, and it sounds like you have a picture in your head of exactly what the language should be already.
There are a few if you can accept either WxWindows or GTK or QT as a toolkit.
In the order of my personal preference would be:
Eiffel Studio
D with the D-GTK binding
F#
javascript?
might be not the fastest one and doesn't fully address all your needs, but hey... its everywhere and easy to learn
didn't read after the list, but with prism You can probably achieve most your goals.
or You can try Qt and c++ autopointers
Silverlight could actually give you enough cross-platform availability to use C#/.NET, but I am not sure it fits all your requirements.
Sounds like Action Script 3 will make you happy. But it's more web oriented but you could try to make a projector or an Air application. I think it's a good solution because you can do anything with AS3 (image, video, text, sound video text keyboard and mouse input, pear to pear and 3d since flash 10, ...) and it's cross platform and you can use it on the web or your desktop :)
If you are a pure root coder (using vim and only command line for ex) you can make your whole app without using the flash ide, by just writing your as files and compiling them with mxmlc (that comes with the free flex sdk).
I suggest Python. Although it doesn't fit your first requirement of coding style, but it fits all your other requirements!
GUI Development: Easy, elegant, and platform-Native styling --> Yes
I'd suggest that you try wxPython (wxWidgets for Python). This is so "native" on Python that about 90% of all the wxWidgets code examples on the Internet are for Python! I've personally used TkInter, Gtk and wxPython. All of them are well supported on Python. My personal choice is wx.
Community: Widely documented, active development, friendly & helpful, unity of focus --> YES
Object-oriented --> Yes
Garbage Collection, no worrying about pointers, etc --> Yes
Native compilation, NO 3rd-party runtimes like GTK or .NET --> Yes. - You can eiter:
pack a single dll with your code - or
use py2exe which is able to create a single executable out of your project
Multi-platform (can be compiled on *nix, Windows, Mac) --> Yes.
Reasonably fast --> Yes. Well, it's not the fastest out there, but close enough that some serious projects are done in Python only.
Mixed typing (soft-typed, OR both soft- and strict-typed -- i.e. Pike) --> Yes.
Regarding your first requirement I'd say that you should give Python at least a try. It requires very little effort to get started. There is a 2-hour tutorial which gives you a serious introduction. There's a Basic to Advanced tutorial where I'd almost guarantee that you'll be writing your first application on the second day.
I also feel your pain Brian. Most time when I ask questions about desktop GUIs the only answer I get is: "Make it Web". You really nailed it, since your question is still open inspite some really non-constructive answers...
I've been watching closely JavaFX 2, it solves some of Swing problems and seems very promising. This may be the only thing Oracle did right since getting Java from Sun.
UPDATE:
.NET is finally becoming an open-source, cross-platform solution. .NET Core allows native compilation for multiple devices.
The new .NET experience is exactly what I was looking for when I asked this question several years ago.
Original:
Lots of good suggestions, despite being salted with negativity throughout.
I think I'm going to go with C# and Mono. I like C# well enough syntactically (I've been accused often of being shallow, but the syntax of a language is just as important to me as its features, because I spend a lot of time writing in that particular syntax). Although similar to Java, it has a few unique features that I appreciate, and I think the community seems more open-minded.
My biggest complaint about Java besides performance, frankly, is the community. It seems infected with an excess of arrogance, and it also seems to be very fragmented in terms of support for and development on various overlapping libraries, tools, and so on. The community surrounding Mono seems much more organized.
Actually, so does .NET itself, for that matter. Sun is a big enterprise company that seems every bit as confused about what it IS and what it DOES as Microsoft or IBM, yet they seem to be doing an even worse job of leading and organizing their platform than Microsoft, which is pretty tragic.

What is the significance for Ruby programmers of SAP's new implementation of Ruby?

SAP announced Blue Ruby, a version of Ruby that runs inside the ABAP Virtual Machine.
This seems to lend additional credibility to the Ruby language but, except for SAP developers, does this have any applicability to the rest of the Ruby community?
I'm just wondering what other significance this may have. Additional job opportunities, perhaps, for Ruby developers to be hired to work on SAP projects?
Any other potential benefits for Ruby programmers?
Also, something I'm not clear about: Besides MRI and JRuby, how many different implementations are there and why do I, as a Ruby programmer, need any implementation except the MRI? I understand I might need JRuby if I want to integrate with Java libraries. Are there any other times I might need to look into an implementation besides the MRI or JRuby?
I notice that Blue Ruby is compiled. Is that a big benefit and would this be the first compiled version of Ruby?
Sorry - maybe too many questions but this is being discussed as a big deal except I'm not sure why/if it really is. Would be grateful to get some feedback from people who understand Ruby (and I.T.) better than I do.
There are actually quite a few alternative implementations. The reason for so many versions is partly because while Ruby itself has a lot of fans, MRI is often considered to be not quite as nice as the language it hosts.
This is a list of all the other Ruby implementations I know of:
MRI
JRuby for Java. Its speed advantage isn't as great now that Ruby 1.9 is out, but it's still a big player for its integration with Java.
IronRuby (still in development) for .NET
MacRuby for making native Mac OS X applications. It's currently based on Ruby 1.9, but they're going to release a new LLVM-based virtual machine for the next version, which looks to offer a major speed boost and will hopefully be portable to other LLVM target platforms.
MagLev (still very much in development) for high-capacity Web apps. It will probably be a commercial product.
Rubinius is a ground-up reimplementation meant as an alternative to MRI with a much cleaner foundation.
I doubt Blue Ruby will have much of an impact on the general software development landscape. It will probably be nice for SAP programmers and allow them to cast a wider net for potential hires since Ruby is somewhat more popular than ABAP.
All of the current Ruby implementations are compiled to bytecode. Contrary to SAP's claims, as of Ruby 1.9, MRI itself includes a bytecode compiler, though the ability to save the compiled bytecode to disk disappeared somewhere in the process of merging the YARV virtual machine. JRuby is compiled into Java .class files. I don't have a lot of details on MagLev, but it seems safe to say it will take that road as well.
Each implementation has its own use cases. JRuby is useful for much the same reasons Jython is. IronRuby will be useful in a .NET environment, when it exists in a usable state.
Things like this make Ruby more acceptable on the Enterprise level, and hasten the spread of Good Programming Languages.
Of course, Blue Ruby is intended for SAP related people. I don't think is going to have much more of an impact on the Ruby community because most Ruby developers are not related to ABAP development.
The main purpose of Blue Ruby is to bring a powerful Scripting Language into the ABAP world, providing more tools for ABAP developers.
You can read my blog on Blue Ruby providing an SE16 (Data table explorer) emulator.
https://weblogs.sdn.sap.com/pub/wlg/14222
Greetings,
Alvaro "Blag" Tejada Galindo.
Senior ABAP Consultant - SAP Mentor.

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