27/09/2011

How to contact Facebook or delete your account

Contacting Facebook can really be a pain, but definitely deleting your account is even harder. Since they rely on your data to survive, they will hang on to it as long as possible.

Luckily, Mary Smith gathered all possible ways to contact Facebook and receive support. Feature requests, suggestions, bug reports and account deletion can all be found there.

You can even request Facebook to send you a CD copy of all the data they have about you accordingly with your country's privacy laws.

By the way, good luck at getting Facebook to reply to you, especially with the data request. If they don't answer, insist since they MUST satisfy your request within a limited time.

UPDATE: An anonymous user pointed out that more information about that is available at  webmarketing-conseil.

13/09/2011

Legend of Dragoon fix disc 2 freeze after Lenus & Regole battle

ENGLISH: please refer to supercheats, quick summary: beat the battle without ever going Dragoon

ITALIANO:
The Legend of Dragoon é uno di quei giochi che non risentono dell’etá. Purtroppo, se si prova a giocarlo su una qualsiasi console che non sia la ormai rara PlayStation 1 (PS2, PS3, PSP o usando  l’emulatore PSX), per qualche motivo dopo la battaglia contro Lenus e Regole verso la fine del disco 2, lo schermo diventa nero ed il gioco va in freeze senza possibilitá di recupero.


10/08/2011

Portugal.. como un Jarro

Ci sono un Irlandese, un Portoghese e due Italiani in Portogallo con un jarro in mano.. Scopri come va a finire guardando le foto




31/07/2011

GNOME 3 add applications taskbar/panel

GNOME 3 does not have, like GNOME 2, two taskbars: one for the applications and one for the system tray. It is possible to add the application taskbar (which includes a system tray panel too) manually with the project tint2. All instructions for installing under different distros are available directly on the developers website.

ITALIANO:


GNOME 3 enable right click on desktop and show icons

GNOME 3 by default doen’t show any icon on the desktop and does not allow right-clicking it. You could change this behaviour manually:
  • run yum install dconf-editor as root or install it via add/remove software and launch it when it’s ready
  • navigate the menus through org –> GNOME –> Desktop –> Background
  • search for the show-desktop-icons entry and chek its checkbox
ITALIANO:

GNOME 3 add minimize and restore buttons to windows

GNOME 3 by default shows only the “close” button on windows. You could add the other two (minimize and restore/maximize) manually:
  • run yum install gconf-editor as root or install it via add/remove software and launch it when it’s ready
  • navigate the menus through Desktop –> GNOME –> Shell –> Windows
  • search for the button_layout entry and edit its value to :minimize,maximize,close (colon included!)
  • restart nautilus or log out and in again to see the changes take effect

ITALIANO:

Realtek wireless on Fedora

This article applies to the 819x Realtek wireless cards series like models 8191SEvB, 8191SEvA2, 8192SE, …

Main reference site is Stanislaw Gruszka’s compact wireless website.

You can either try the -stable version or the –next. Both have different kernel requirements, the –next version, though more unstable, is compiled against the latest kernel version so you should run yum update kernel as root before installing the appropriate package for your system.

After installation you will have to reboot the system before being able to use and control your wireless card through NetworkManager.

 

ITALIANO:

 

Questo articolo si applica ai modelli di schede wireless Realtek serie 819x quali 8191SEvB, 8191SEvA2, 8192SE, …

Il sito di riferimento é compact wireless di Stanislaw Gruszka.

Potete provare sia la versione -stable che la –next. Entrambe hanno differenti requisiti di kernel, la versione –next, sebbene piú instabile, é compilata per l’ultima versione del kernel supportata dal sistema per cui é sufficiente lanciare yum update kernel da root prima di installare il pacchetto corretto per il proprio sistema.

Al termine dell’installazione sará necessario riavviare il sistema prima di poter usare e controllare la propria scheda wireless attraverso il NetworkManager.

20/07/2011

[MatLab] EM – Expectation Maximization reconstruction technique implementation

EM – Expectation Maximization is an iterative algorithm used in tomographic images (as in CT) reconstruction, very useful when the FBP – Filtered Back Projection technique is not applicable.

Basic formula is:

f_k+1 = (f_k / alpha) (At (g / (A f_k)))

where:

  • f_k is solution (the resulting reconstructed image) at k-th iteration, at first iteration it is our guess
  • g is image sinogram (what we get from the scanning)
  • A f_k is Radon transform of f_k
  • At is inverse Radon
  • alpha is inverse Radon of a sinogram with all values 1 which represents our scanning machine

Get the source code here.

[MatLab] SIRT - Simultaneous Iterative Reconstruction Technique implementation

SIRT – Simultaneous (algebraic) Reconstruction Technique is an iterative algorithm used in tomographic images (as in CT) reconstruction, very useful when the FBP – Filtered Back Projection technique is not applicable.

Basic formula is:

f_(k+1) = f_k + At (g - A f_K)

where:
  • f_k is solution (the resulting reconstructed image) at k-th iteration, at first iteration it is our guess
  • g is image sinogram (what we get from the scanning)
  • A f_k is Radon transform of f_k
  • At is inverse Radon

Get the source code here. Note: this sample code is to showcase the algorithm. It does not use FBP for the iradon, it adds noise, it normalizes the image values as per OUR needs. Given these difficult conditions, it still produces an amazing result.

Please check the comments carefully and tailor it to your use case!

[MatLab] Filter a tomographic image in Fourier’s space

MatLab has built-in functions to simulate acquisition and elaboration of tomographic (as in CT) images. When it comes to filtering the image prior to back-projecting it, it is possible to do it yourself without relying on the (good as in Shepp-Logan) filters MatLab has.

 

We will filter our image in Fourier’s space. For each column of the sinogram, we:

When we reconstruct our image WITHOUT having MatLab apply any filter, we’ll see the image, filtered with our filter, as a result. Get the source code here.

06/07/2011

[PHP] PageRank implementation




There are two possible PageRank implementations: the power method and the iterative method. We will describe both.

To check the results obtained we provide a scri'pt to generate a .gexf file to be opened with Gephi.

Test datasets are available at the Toronto university website.


Technologies used:
  • PHP
  • Gephi
  • XML
1.Power method
 

This method takes longer than the other one, however the result is equally right. Using a sparse matrix instead of the full one may help speed up the process.

Method description:

  1. Pick the NxN input matrix and make it stochastic, call it A
  2. Create the P" matrix as alpha*A+(1-alpha)*M with alpha a factor which describes the probability of a random jump and M an NxN matrix filled with values 1/N
  3. Create starting vector v_0 with length N filled with values 1/N
  4. Compute v_m = v_m-1*P" where the first time v_m-1 is exactly v_0
  5. Compute the difference v_m - v_m-1 which should converge to 0
  6. When the difference doesn't vary over a certain threshold or i iterations have been made, stop. v_m should contain the PageRank for every page
To run the program you must have the nodes and adj_matrix files from the chosen dataset. The implementation source code is found here here.

NOTE: Due to Apache and PHP limitations, you may have to modify the php.ini file to grant more memory to the scripts (if you don't want to store the matrix on filesystem like we did) by setting the memory_limit parameter to at least 768MB and raising the maximum script execution time to 5 minutes(300 seconds) with max_execution_time.

2. Iterative method - found on phpir

To use this method you must have the
nodes and adj_list files from the chosen dataset.




Method description:


Each page is given a starting PR of 1/N where N is the number of nodes in the graph. Each page then gives to every page it links a PR of current_page_PR/number_of_outbound_links.
It's introduced a dampening factor alpha (0,15) which represents the probability of making a random jump while visiting the graph or when reaching a cul de sac.

PR_new = alpha/n + (1-alpha)*PR_old




Every PR is then normalized between 0 and 1.

The process keeps going until it has reached i iterations or the difference between old and new PR doesn't vary over a certain threshold.

Our implementation is available here.


3. Gephi parser:

To use the
parser you you must have the nodes and adj_list files from the chosen dataset. The parser outputs a .gexf file to be opened with Gephi. Here is a sample .gexf file obtained by parsing the first dataset available on the site (the one about abortion).

25/05/2011

pro-AD website: MRI analysis for prodromal Alzheimer’s assessment

Recently I participated in the pro-AD’s website development.


pro-AD is a website created at DIFI, the University of Genoa’s Department of Physics, to help medics automagically analyse MRI images for the prodromal Alzheimer's disease assessment.

Registered medics can easily submit DICOM or NII files through the website to their private local folder via the java applet JUploader or the PHP uploader which is shown automatically when no java plugin is detected on the user's browser. They can then modify the information associated with those images: age, gender and an optional unique ID - no personal data about the patients is stored anywhere anytime during the process.


Easy access for the medic's personal profile is provided through a dedicated page; if a valid e-mail address is provided, it is possible to enable e-mail notifications about processing results.


When one or more files are selected for processing, the server enqueues them in a multithreaded pipeline and starts the analysis. At the end, a single number which describes the patient's likelihood of being affected in the near future by the disease is returned for each file sent to processing. If the file processed was of really bad quality or was not a valid file, the process fails and an error is shown instead of the result.


All results are stored for easy future access and can be viewed and exported in XLS format from a dedicated page. If a file is sent to processing more times, only the latest result is stored.

[PHP] Create XLS document

If you need to create XLS documents via PHP, you may need these functions:

//XLS Begin of file
function xlsBOF() {
echo pack("ssssss", 0x809, 0x8, 0x0, 0x10, 0x0, 0x0);
return;
}
//XLS End of file
function xlsEOF() {
echo pack("ss", 0x0A, 0x00);
return;
}
//Writes a number in a cell
function xlsWriteNumber($Row, $Col, $Value) {
if($Value == null){
xlsWriteLabel($Row, $Col, $Value);
}
else{
echo pack("sssss", 0x203, 14, $Row, $Col, 0x0);
echo pack("d", $Value);
}
return;
}
//Writes a string in a cell
function xlsWriteLabel($Row, $Col, $Value ) {
$L = strlen($Value);
echo pack("ssssss", 0x204, 8 + $L, $Row, $Col, 0x0, $L);
echo $Value;
return;
}

//Creates headers to download the file
function xlsWriteHeader(){
// Send Header
header("Pragma: public");
header("Expires: 0");
header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
header("Content-Type: application/force-download");
header("Content-Type: application/octet-stream");
header("Content-Type: application/download");;
header("Content-Disposition: attachment;filename=EXPORTNAME.xls ");
header("Content-Transfer-Encoding: binary ");
}

[PHP] Send mail with attachment using PEAR

If you use PEAR and want to send mails with attachments via PHP, you may find this helpful.

First, ensure you have installed PEAR’s Mail and Mail_mime packages. Then, you just need a function like this:

 

function send_mail($mail, $subject, $bodytxt, $bodyhtml, $attachment){
    require_once('Mail.php');
    require_once('Mail/mime.php');
    //mail parameters, this is the basic one
    $params = array("host"=>"YOUR_HOST");
    //creates smtp mail object
    $mail_sender = Mail::factory("smtp", $params);
    //creates mail headers
    $headers = array("From"=>"YOUR_ADDRESS", "To"=>$mail, "Subject"=>$subject);
    //creates attachment and body fields
    $crlf = "\n";
    $mime = new Mail_mime($crlf);
    $mime->setTXTBody($bodytxt);
    $mime->setHTMLBody($bodyhtml);
    $mime->addAttachment($attachment, "ATTACHMENT_TYPE");
    //never change these lines order
    $body = $mime->get();
    $headers = $mime->headers($headers);
    $error=$mail_sender->send($mail, $headers, $body);
    return $error;
}

 

where:

  • YOUR_HOST is your mail host, something like smtp.gmail.com
  • $mail is the recipient’s mail address
  • $bodytxt is the mail’s body in TXT format, do not use HTML markup here!
  • ATTACHMENT_TYPE is the attachment’s MIME type as per IANA’s specifications, something like image/jpeg
  • if you change the order of the last lines, the attach operation will not work

13/05/2011

[PHP, XML] Twitter friends graph

Brief example on how to create and draw some Twitter user’s friends graph.

Piccolo esempio di come creare e disegnare il grafo dei friends di un dato utente Twitter.

 

English:

With friends Twitter means “people whom the user follows”. Starting from a chosen user, we grab all his friends until a depth level of 3 and we create a XML file with a proper structure to be opened by Gephi in order to graphically visualize the result. The number of users we get is far lower than the real one due to Twitter API’s limitations.

To create the gexf file for Gephi, just run the HowDoYouGraph script after editing the $username variable with the desired username. After a little coffee break, in the same folder as the script you should find a file named grafo.gexf.

 

Show an example graph for user VivoMikiX and download the gexf source.

 

Stats about the undirected example graph:

  • Total nodes: 5013
  • Total edges: 5539
  • Medium degree = 2.21
  • Diameter = 6
  • Density = 0
  • Modularity = 0.876
    • Number of communities = 72
  • Weakly connected components = 1
  • Medium clustering coefficient = 0.014
    • Total triangles = 202
  • Eigenvector centrality with 300 iterations = 0.0325
  • Medium path length = 4.496
    • Number of shortest paths = 25125156
    • Radius = 3

 

Italiano:

Con friends si intendono tutte le persone che l'utente segue. Partendo da un dato utente, recuperiamo i suoi friends fino al livello 3 e generiamo un file XML con una struttura gradita a Gephi per visualizzare graficamente il risultato. Il numero di utenti recuperati e' inferiore al numero reale a causa di limitazioni imposte dalle API di Twitter.

Per creare il file gexf per Gephi, basta far girare lo script HowDoYouGraph dopo aver modificato la variabile $username con lo username desiderato. Dopo aver preso un caffe', nella stessa cartella dello script apparira' un file chiamato grafo.gexf che e' quello che ci interessa.

 

Visiona un grafo di esempio per l’utente VivoMikiX e scarica il file gexf sorgente.

 

Statistiche sul grafo d’esempio, considerandolo indiretto:

  • Totale nodi: 5013
  • Totale archi: 5539
  • Grado Medio = 2.21
  • Diametro = 6
  • Densità = 0
  • Modularità = 0.876
    • Numero di Comunità = 72
  • Componenti connesse debolmente = 1
  • Coefficiente di Clustering Medio = 0.014
    • Triangoli totali = 202
  • Centralità di autovettori con 300 iterazioni = 0.0325
  • Lunghezza cammino medio = 4.496
    • Numero di percorsi piu' corti = 25125156
    • Raggio = 3

31/03/2011

[PHP, JavaScript] Twitter, Google Maps, YouTube API mashup

Where you followin' me?

English:

A mashup with Twitter, Google Maps and YouTube APIs.

We grab some Twitter user's followers, show them on Google Maps and include YouTube videos about the city where most followers live.

Italiano:

Un mashup con le API di Twitter, Google Maps e YouTube.

Si recuperano i follower di un certo utente Twitter, si mostra la loro concentrazione su Google Maps e si includono dei video riguardanti la cittá in cui risiede la maggior parte dei follower.