Continue reading »]]> Yesterday I posted about Cut The Rope being ported to HTML5+Javascript. Today, I continue the same topic, but with a different view. I’ve came across this fantastic site that puts a whole Gameboy Color Game Center in the browser, using the power of Javascript and HTML5, created by Grant Galitz. Now we are starting to get the dimension this change will have. You can see it in action here. He also has his open-source GameBoy Online Project, which source can be downloaded for free from GitHub.

From my perspective, with everything we have seen until now, Adobe’s Flash is slowly going to be abandoned if Flash fails to bring anything new. There’s lots of examples of applications and effects that have been achieved using Flash in the past, but today we can build these using just web technologies. This ranges from the simple image galleries to word processors.

There is a also a blog about games being developed with HTML5 here: http://www.html5gamedevs.com/

What do you think about this HTML5 revolution?

Continue reading »]]> In order to show developers the power of HTML 5, the astonishing successful mobile game Cut The Rope has been partially ported from Objective-C to Javascript and can be played for free in http://www.cuttherope.ie/, sponsored by Microsoft’s Internet Explorer, with some unique levels in this version, like the one below.

In the up-right corner of the website, you will find a link to Behind the Scenes developer section, where I found some interesting notes:

We think that the HTML5 version makes the web more fun and it demonstrates the advances in standards support made in the latest version of Internet Explorer. With that in mind, we want to share some of the cool “behind the scenes” technical details used on this project to help you build your own HTML5 sites and ultimately get ready for the Windows 8 Store!

Regarding performance, the developer section shows a comparison table with the average framerate on some different systems.

You can see that you can get almost the same Framerate whether using Win7,i7 CPU and 8GB RAM and a Win8,i5 CPU and 4GB RAM. But wait! RAM “quantity” is not really important, nor CPU speed. I think the most important component to compare here is the GPU (a lacking column in this table), namely the GPU Clock Frequency and RAM, that have much more influence in FPS than the aspects shown here, so I’d like to see some independent tests and comparisons between Browsers on the same system (like they did with Windows 7 here, but with different systems, which will obviously change the results).

Appart from that browser wars, I was flabbergasted by seeing one of the last year’s most bought games running fully on JavaScript + HTML5. This shows how promising the web can be in the very near future.

Finally, here is the video on the dev page on YouTube.

Continue reading »]]> Professor Andrew Ng and his team from University of Stanford provided free online lessons about machine learning. Students are provided video sessions and slide presentations in both PDF and PPTX, as well as some practical exercises.

You don’t even need to have a lot of Maths background, as the course has some introductory content on Algebra and other concepts that are needed to understand the more advanced lessons. Although the course is already finished, you can still register and watch the videos and download complete PDFs. Here is an overview of the course:

01. Introduction to Machine Learning
02. Linear regression with one variable
03. Linear algebra review
04. Linear regression with multiple variables
05. Octave Tutorial
06. Logistic regression
07. Regularization
08. Neural Networks: Representation
09. Neural Networks: Learning
10. Advice for Applying Machine Learning
11. Machine Learning System Design
12. Support Vector Machines
13. Clustering
14. Dimensionality Reduction
15. Anomaly Detection
16. Recommender Systems
17. Learning with Large Datasets
18. Application Example: Photo OCR

You can start yourself in machine learning today.
Go to http://www.ml-class.org/, register and take your time watching the videos and practicing.

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In this mini-article I will show you how I develop applications for Linux in XCode 4. At the moment I’m using XCode 4.2.1, in OSX Lion, with Ubuntu 10.04 running on a virtual machine.

Although the article is related to XCode, after reading and trying out for yourself, you will notice that you can use whatever IDE you like. Here I’m just showing you how you can code in a OSX-only IDE and deploy in Linux.

Requirements

You will need some tools before we start:

• VMWare or similar virtual machine application for Mac
• Used to run our Linux system, and that’s where we will compile and run the target application.
  You can also use a physical computer instead. However, you will need network connectivity from mac to that computer because the communication between this linux System and our Mac is done by SSH.
• OSXFuse
• Requirement for the next point
• SSHFS
• It will be used to mount a remote directory in our Mac, and access it as if it was an external hard disk drive

Once you have all these, we are ready to go, but take some seconds to make sure you can compile the application in your slave Linux system. This will ensure that any problems you may encounter are not related to your slave machine or the code you are trying to compile.

Accessing slave machine using SSH

Now you will need the slave machine’s IP address, typing ifconfig in its Terminal.

As you can see in the image above, in my case I’ll be using 172.16.68.128 as the slave’s IP Address.

Then we make sure we can access it from your Mac typing the next command in Mac Terminal:

ssh username@ip

If we are asked for the password, then we got a valid SSH connection and we can move on…

Adding an alias for the Linux Slave IP

Because IPs can change sometimes, even inside Local Area Network, I added an alias for this IP, so that I could use it in scripts instead of the IP address itself. When it changes, I only have to modify one single file. You can do the same, by editing the hosts file, so grab the Mac Terminal and type as you see:

sudo vim /etc/hosts

Add a new line in the end, pressing I to enter insert mode:

172.16.68.128 vmcode

Now press ESC to exit “INSERT mode” and type :wq (yes, including the colon). If you have any problems using vim to edit this file, you can try nano instead – just replace “vim” with “nano” in the first command of this section. Now, you can use the virtual hostname “vmcode” instead of the real IP (which will be a lot easier to remember).

Setup script files

Now we need to setup two script files. I called them mountDir and sshbuild. The first one will mount the remote directory in our Mac and the latter is used to remotely compile the application.

Firstly pick a directory for these scripts, where you need to place the sshfs-static-leopard file, because it will be needed for the mountDir script.

Mounting Directory Script

Using your favorite text editor, create a new file called “mountDir” (no extension), and paste the following code:

#!/bin/bash
echo password | ./sshfs-static-leopard username@vmcode:codedir ~/path/to/mount/dir -o password_stdin

I’m explaining some of the variables in the command, that you should change to fit your needs:

• username and password are the credentials for the user in the slave Linux machine
• codedir is the directory in slave machine you want to mount in Mac
• ~/path/to/mount/dir is the path to the Mac’s directory where you want to mount the slave’s directory

Building remotely

The SSH command accepts a second argument, that is the command you want to execute right after the remote login. Save and create another file called “sshbuild” with the following content:

#!/bin/bash
ssh username@vmcode 'cd codedir; make'

Note that username and codedir must match the ones you used before.

Setting up XCode

Before we move to XCode, you first need to mount the directory: open the Terminal, cd to your scripts dir, and run sh mountDir. Now you should see the contents of remote dir in your Mac’s ~/path/to/mount/dir.

Start XCode, then click File > New > New Workspace… and chose a location for the workspace file (I used the same as the scripts). You should see a window with three different spaces, they should have texts in the middle, from left ro right, saying “No Files”, “No Editor” and “No Selection”. Open a Finder window in the location ~/path/to/mount/ and then drag the subfolder that has a name starting with “OSXFUSE” to the “No Files” space in XCode.

A popup will show up. Firstly, XCode will prompt you about your build tool. You should type the complete path to the sshbuild script, starting on root, on the “Build Tool” field.

After clicking “Next”, you will be presented something like the image below, you should select the second option, which is “Create folder references for any added folders”.

Basically you are adding a reference to that directory, so instead of working in a local copy, you will edit the remote files directly. Now that you have all the directories in the slave’s codedir in the left panel of XCode, you can now open, edit and save any of your files using XCode. Now hit Command+B to run the build tool, and if everything goes well, you should see a message box saying Build Successful.

Running the Application

As you are developing for Linux, you should preferably debug under Linux. However, I often use an Application called X11, taht can be found in your Applications/Utilities folder. Type this command under X11 console window and the application should run in your Mac as if it was on Linux, even if it needs to open windows:

ssh -X username@vmcode
cd codedir
./application

Conclusion

Here I shown you how I develop applications for Linux using the resourceful XCode and all it’s features, without quitting Mac OSX. I hope you found it useful and it helps you by increasing your productivity. Leave a reply, share your thoughts and suggestions and happy coding

– edit 11/01/2012 –

After reading this article, Simon Elliston Ball posted a reply with a link to his blog suggesting a different solution – vagrant – that let’s you achieve the same results, but storing your files on Mac instead of the Linux system. I believe there are some advantages of doing this way, so you may choose the solution that best fits your needs. Thank you Simon.

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It’s always amazing to see how nature is so beautiful that solves many of our difficult problems. By studying the tail technique of a lizard, a research group could effectively improve their robot’s stability just by adding an active tail to it with algorithms that somehow reproduce the animal’s behaviour.

Via Automaton

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The new NAO has been presented by Aldebaran in this video, with a 1.6GHz processor and two HD cameras. The old version is the official platform for the RoboCup Standard Platform League, and in RoboCup 2011 (Istanbul, Turkey) I’ve came across some complaints about the NAO design, being most of them related to the hip joint. It saddens me that this issue wasn’t taken into account for the Next Gen version design.

I strongly believe the hardware improvements on the CPU and the cameras will make a difference, but let’s hope it’s for better. Higher resolutions and CPU speed always have higher power demands, so if they didn’t upgrade the battery capacity, we will watch more and more NAO falling to the ground, begging for some volts.

In terms of Software, Aldebaran’ press release highlights the new “Nuance programme”, which is said to be “capable of isolating and recognizing a specific word within a sentence or a conversation”. We will be waiting to find out if this is the new competitor to Siri in voice recognition, or just another one.

Leave your message.

Continue reading »]]> You may have already heard about “port forwarding”. But what is it, exactly? Here is your answer: port forwarding is the redirecting of computer signals to specific electronic paths into your computer.

You need to forward a port when you are “behind” a router, which is your gateway to the World Wide Web. When network data comes from Internet to your router, the type of this data can vary a lot and ports are the way your router differentiates web sites, file downloads, and online games, because they are each assigned a port number.

By using port forwarding, the router or firewall sends the correct data to the correct place!

In a LAN (Local Area Network), every computer has an internal IP, but everyone share the same external IP (this is the one visible from outside – Internet). Let’s look at the following example.

Setting up a WebServer

So, you have your WebServer running and can access it inside your LAN (please note the standard port for HTTP communication is 80). Now you want to open it to one of your friends. The way your friend can reach your network is by your external IP. When you give your external IP to your friend and he puts it in a browser, it will send a request to your router, for port 80. But your router’s internal Firewall will probably block the access, unless you have forwarded the port.

So, by forwarding port 80 to your computer (internal IP), you will tell your router to redirect every request on port 80 to your computer.

How to Port Forward?

This is an easy question, but it doesn’t have an easy answer, as it hardly depends on the Router you have. There is a huge list of router models on this website, which will help you through the process. The site also provides a database of known application ports.

Common Used Ports

• HTML: port 80
• FTP: port 21
• POP3 email: port 110
• MSN Messenger: port 6901 and ports 6891-6900

Continue reading »]]> For the last two years I’ve intensively used two different computers – desktop + laptop – and one thing that really annoyed me was having two keyboards and two mice cluttering up my workspace.

Recently I came across a tiny server-client application that allows the user to share the keyboard and the mouse with another computer (running Windows, OSX or other Unix) – Synergy. All you need is a network connection between all the machines.

By having the server on my desktop, and the client on my MacBook, I am now using one single keyboard and one mouse to control both computers, without having to change between peripherals. The clipboard is also shared, so don’t bother reading in one computer to write on the other.

Here is a very good tutorial on how to setup Synergy:
http://lifehacker.com/254648/how-to-control-multiple-computers-with-a-single-keyboard-and-mouse

Continue reading »]]> This is something very simple and at the same time very useful. It saved me a lot of time when I needed to move content from old site to the new one. Here is the simple query:

update [table_name] set [field_name] = replace([field_name],'[string_to_find]','[string_to_replace]');

Continue reading »]]> Hello everyone. Today is the day I launch this new website.

Note that just the most important content will be moved from the old site to this one. I want to keep it clean and fast. I hope you like the new design and feel free to give your suggestions.

Drupal, you disappointed me. Although I did not update the site regularly, the administration pages became unbearably slow. After noticing that, I started doing some analysis on the user loading time and I found that there were days where the site took more than 30 seconds to load mean. This is not acceptable. Now, here it is, faster than ever, after moving to WordPress, I expect you to have a friendlier user experience.

An improvement has been made in social terms, too. Now I provide Facebook and Twitter integration. This will make you feel part as the site too…

Best regards!