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• How do you create large, growable, shared filesystems on Linux at AWS?

  - by Reece

  What are acceptable/reasonable/best ways to provide large, growable, shared storage at AWS, exposed as a single filesystem? We're currently making 1TB EBS volumes ~biweekly and NFS exporting with no_subtree_check and nohide. In this setup, distinct exports appear under a single mount on the client. This arrangement does not scale well. The options we've considered: LVM2 with ext4. resize2fs is too slow. Btrfs on Linux. not obviously ready for prime time yet. ZFS on Linux. not obviously ready for prime time yet (although LLNL uses it) ZFS on Solaris. future of this combo is uncertain (to me), and new OS in the mix glusterfs. heard mostly good but two scary (and maybe old?) stories. The ideal solution would provide sharing, a single fs view, easy expandability, snapshots, and replication. Thanks for sharing ideas and experience.

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• Flood fill algorithm for Game of Go

  - by Jackson Borghi

  I'm having a hell of a time trying to figure out how to make captured stones disappear. I've read everywhere that I should use the flood fill algorithm, but I haven't had any luck with that so far. Any help would be amazing! Here is my code: package Go; import static java.lang.Math.*; import static stdlib.StdDraw.*; import java.awt.Color; public class Go2 { public static Color opposite(Color player) { if (player == WHITE) { return BLACK; } return WHITE; } public static void drawGame(Color[][] board) { Color[][][] unit = new Color[400][19][19]; for (int h = 0; h < 400; h++) { for (int x = 0; x < 19; x++) { for (int y = 0; y < 19; y++) { unit[h][x][y] = YELLOW; } } } setXscale(0, 19); setYscale(0, 19); clear(YELLOW); setPenColor(BLACK); line(0, 0, 0, 19); line(19, 19, 19, 0); line(0, 19, 19, 19); line(0, 0, 19, 0); for (double i = 0; i < 19; i++) { line(0.0, i, 19, i); line(i, 0.0, i, 19); } for (int x = 0; x < 19; x++) { for (int y = 0; y < 19; y++) { if (board[x][y] != YELLOW) { setPenColor(board[x][y]); filledCircle(x, y, 0.47); setPenColor(GRAY); circle(x, y, 0.47); } } } int h = 0; } public static void main(String[] args) { int px; int py; Color[][] temp = new Color[19][19]; Color[][] board = new Color[19][19]; Color player = WHITE; for (int i = 0; i < 19; i++) { for (int h = 0; h < 19; h++) { board[i][h] = YELLOW; temp[i][h] = YELLOW; } } while (true) { drawGame(board); while (!mousePressed()) { } px = (int) round(mouseX()); py = (int) round(mouseY()); board[px][py] = player; while (mousePressed()) { } floodFill(px, py, player, board, temp); System.out.print("XXXXX = "+ temp[px][py]); if (checkTemp(temp, board, px, py)) { for (int x = 0; x < 19; x++) { for (int y = 0; y < 19; y++) { if (temp[x][y] == GRAY) { board[x][y] = YELLOW; } } } } player = opposite(player); } } private static boolean checkTemp(Color[][] temp, Color[][] board, int x, int y) { if (x < 19 && x > -1 && y < 19 && y > -1) { if (temp[x + 1][y] == YELLOW || temp[x - 1][y] == YELLOW || temp[x][y - 1] == YELLOW || temp[x][y + 1] == YELLOW) { return false; } } if (x == 18) { if (temp[x - 1][y] == YELLOW || temp[x][y - 1] == YELLOW || temp[x][y + 1] == YELLOW) { return false; } } if (y == 18) { if (temp[x + 1][y] == YELLOW || temp[x - 1][y] == YELLOW || temp[x][y - 1] == YELLOW) { return false; } } if (y == 0) { if (temp[x + 1][y] == YELLOW || temp[x - 1][y] == YELLOW || temp[x][y + 1] == YELLOW) { return false; } } if (x == 0) { if (temp[x + 1][y] == YELLOW || temp[x][y - 1] == YELLOW || temp[x][y + 1] == YELLOW) { return false; } } else { if (x < 19) { if (temp[x + 1][y] == GRAY) { checkTemp(temp, board, x + 1, y); } } if (x >= 0) { if (temp[x - 1][y] == GRAY) { checkTemp(temp, board, x - 1, y); } } if (y < 19) { if (temp[x][y + 1] == GRAY) { checkTemp(temp, board, x, y + 1); } } if (y >= 0) { if (temp[x][y - 1] == GRAY) { checkTemp(temp, board, x, y - 1); } } } return true; } private static void floodFill(int x, int y, Color player, Color[][] board, Color[][] temp) { if (board[x][y] != player) { return; } else { temp[x][y] = GRAY; System.out.println("x = " + x + " y = " + y); if (x < 19) { floodFill(x + 1, y, player, board, temp); } if (x >= 0) { floodFill(x - 1, y, player, board, temp); } if (y < 19) { floodFill(x, y + 1, player, board, temp); } if (y >= 0) { floodFill(x, y - 1, player, board, temp); } } } }

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• SOLID Thoughts

  - by GeekAgilistMercenary

  SOLID came up again in discussion.  What is SOLID?  Well, glad you asked, because I am going to elaborate on the SOLID Principles a bit. Initial Concept S Single Responsibility Principle O Open/Closed Principle L Liskov Substitution Principle I Interface Segregation Principle D Dependency Inversion/Injection Principle The Single Responsibility Principle (SRP) is stated that every object should have a single responsibility and should be entirely encapsulated by the class.  This helps keep cohesion.  Here is a short example, starting with a basic class. public class Car { decimal Gas; int Doors; int Speed; decimal RampJumpSpeed; } Now I will refactor a little bit to make it a bit more SRP friendly. public class Car { decimal Gas; int Speed; }   public class DuneBuggy : Car { decimal RampJumpSpeed; }   public class EconomyCar : Car { int Doors; } What we end up with, instead of one class, is an abstract class and two classes that have their respective methods or properties to keep the responsibilities were they need to be. The Open Closed Principle (OCP) is one of my favorites, which states simply, that you should be able to extend a classes behavior without modifying it.  There are a couple of ways one can extend a class, by inheritance, composition, or by proxy implementation.  The Liskov Substitution Principle (LSP) states that a derived class must be substitutable for their base classes. The Dependency Inversion Principle (DIP) states that one should depend on abstractions and not on concrete implementations. Finally, the Interface Segregation Principle (ISP) states that fine grain interfaces should be client specific. So hope that helps with kicking off a basic understanding of SOLID Principles.  I will be following this entry up with some new bits in the near future related to good software design and practice. Original post.

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• Error while installing GNU Octave packages

  - by carllacan

  I want to install the GNU Octave optim package, but I keep receiving errors in the process. Apparently I need to install some other packages first, one of which is the general package. However, when I try to, I receive this error: octave:17> pkg install general-1.3.2.tar.gz make: /usr/bin/mkoctfile: Command not found make: *** [__exit__.oct] Error 127 'make' returned the following error: make: Entering directory `/tmp/oct-CGIPo9/general/src' /usr/bin/mkoctfile __exit__.cc make: Leaving directory `/tmp/oct-CGIPo9/general/src' error: called from `pkg>configure_make' in file /usr/share/octave/3.6.1/m/pkg/pkg.m near line 1391, column 9 error: called from: error: /usr/share/octave/3.6.1/m/pkg/pkg.m at line 834, column 5 error: /usr/share/octave/3.6.1/m/pkg/pkg.m at line 383, column 9

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• FloodFill Algorithm for Game of Go

  - by Jackson Borghi

  I'm having a hell of a time trying to figure out how to make captured stones disappear. I've read everywhere that I should use the FloodFill algorithm, but I havent had any luck with that so far. Any help would be amazing! Here is my code: package Go; import static java.lang.Math.; import static stdlib.StdDraw.; import java.awt.Color; public class Go2 { public static Color opposite(Color player) { if (player == WHITE) { return BLACK; } return WHITE; } public static void drawGame(Color[][] board) { Color[][][] unit = new Color[400][19][19]; for (int h = 0; h < 400; h++) { for (int x = 0; x < 19; x++) { for (int y = 0; y < 19; y++) { unit[h][x][y] = YELLOW; } } } setXscale(0, 19); setYscale(0, 19); clear(YELLOW); setPenColor(BLACK); line(0, 0, 0, 19); line(19, 19, 19, 0); line(0, 19, 19, 19); line(0, 0, 19, 0); for (double i = 0; i < 19; i++) { line(0.0, i, 19, i); line(i, 0.0, i, 19); } for (int x = 0; x < 19; x++) { for (int y = 0; y < 19; y++) { if (board[x][y] != YELLOW) { setPenColor(board[x][y]); filledCircle(x, y, 0.47); setPenColor(GRAY); circle(x, y, 0.47); } } } int h = 0; } public static void main(String[] args) { int px; int py; Color[][] temp = new Color[19][19]; Color[][] board = new Color[19][19]; Color player = WHITE; for (int i = 0; i < 19; i++) { for (int h = 0; h < 19; h++) { board[i][h] = YELLOW; temp[i][h] = YELLOW; } } while (true) { drawGame(board); while (!mousePressed()) { } px = (int) round(mouseX()); py = (int) round(mouseY()); board[px][py] = player; while (mousePressed()) { } floodFill(px, py, player, board, temp); System.out.print("XXXXX = "+ temp[px][py]); if (checkTemp(temp, board, px, py)) { for (int x = 0; x < 19; x++) { for (int y = 0; y < 19; y++) { if (temp[x][y] == GRAY) { board[x][y] = YELLOW; } } } } player = opposite(player); } } private static boolean checkTemp(Color[][] temp, Color[][] board, int x, int y) { if (x < 19 && x > -1 && y < 19 && y > -1) { if (temp[x + 1][y] == YELLOW || temp[x - 1][y] == YELLOW || temp[x][y - 1] == YELLOW || temp[x][y + 1] == YELLOW) { return false; } } if (x == 18) { if (temp[x - 1][y] == YELLOW || temp[x][y - 1] == YELLOW || temp[x][y + 1] == YELLOW) { return false; } } if (y == 18) { if (temp[x + 1][y] == YELLOW || temp[x - 1][y] == YELLOW || temp[x][y - 1] == YELLOW) { return false; } } if (y == 0) { if (temp[x + 1][y] == YELLOW || temp[x - 1][y] == YELLOW || temp[x][y + 1] == YELLOW) { return false; } } if (x == 0) { if (temp[x + 1][y] == YELLOW || temp[x][y - 1] == YELLOW || temp[x][y + 1] == YELLOW) { return false; } } else { if (x < 19) { if (temp[x + 1][y] == GRAY) { checkTemp(temp, board, x + 1, y); } } if (x >= 0) { if (temp[x - 1][y] == GRAY) { checkTemp(temp, board, x - 1, y); } } if (y < 19) { if (temp[x][y + 1] == GRAY) { checkTemp(temp, board, x, y + 1); } } if (y >= 0) { if (temp[x][y - 1] == GRAY) { checkTemp(temp, board, x, y - 1); } } } return true; } private static void floodFill(int x, int y, Color player, Color[][] board, Color[][] temp) { if (board[x][y] != player) { return; } else { temp[x][y] = GRAY; System.out.println("x = " + x + " y = " + y); if (x < 19) { floodFill(x + 1, y, player, board, temp); } if (x >= 0) { floodFill(x - 1, y, player, board, temp); } if (y < 19) { floodFill(x, y + 1, player, board, temp); } if (y >= 0) { floodFill(x, y - 1, player, board, temp); } } } }

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• Is there a way communicate or measure levels of abstraction?

  - by hydroparadise

  I'll be the first to say that this question is a bit... out there. But here are a couple questions I bear in mind : Is abstraction continuous or discrete? Is there a single unit of abstraction? But I'm not sure those questions are truly answerable or even really makes sence. My naive answer would be something along the lines of abitrarily discrete but not necescarily having a single unit measure. Here's what I mean... Take a Black Labrador; an abstraction that could be made is that a Black Lab is a type of animal. [Animal]<--[Black Lab] A Black Lab is also a type of Dog. [Dog]<--[Black Lab] One way to establish a degree of abstraction is by comparing the two the abstractions. We could say that [Animal] is more abstract than [Dog] in respect to a Black Lab. It just so happens [Animal] can also be used as an abstraction of [Dog] So, we might end up with something like [Animal]<--[Dog]<--[Black Lab] With the model above, one might be inclined to say that there's two hops of abstraction to get from [Black Lab] to [Animal]. But you can't exactly tell somebody they need one level abstraction and reasonalby expect they will come up with [Dog] given they aren't explicity given the options above. If I needed to tell someobody in a single email that they needed an abstract class with out knowing what that abstract class is, is there a way to communaticate a degree of abstraction such that they might end up on Dog instead of Animal? As a side note, what area of study might this type of analysis fall under?

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• Help with complex MVVM (multiple views)

  - by jsjslim

  I need help creating view models for the following scenario: Deep, hierarchical data Multiple views for the same set of data Each view is a single, dynamically-changing view, based on the active selection Depending on the value of a property, display different types of tabs in a tab control My questions: Should I create a view-model representation for each view (VM1, VM2, etc)? 1. Yes: a. Should I model the entire hierarchical relationship? (ie, SubVM1, HouseVM1, RoomVM1) b. How do I keep all hierarchies in sync? (e.g, adding/removing nodes) 2. No: a. Do I use a huge, single view model that caters for all views? Here's an example of a single view Figure 1: Multiple views updated based on active room. Notice Tab control Figure 2: Different active room. Multiple views updated. Tab control items changed based on object's property. Figure 3: Different selection type. Entire view changes

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• Ubuntu 11.10 with KDE installed does not prompt for elevation for privileged ops in all apps

  - by Michael Goldshteyn

  I installed the KDE window manager on top of Ubuntu 11.10 and while I am using KDE, I do not get an elevation dialog when I try to perform tasks that require root privileges. Instead, the operations silently fail, unless I launch apps from a terminal, in which case I get errors like: Traceback (most recent call last): File "/usr/lib/python2.7/dist-packages/softwareproperties/gtk/SoftwarePropertiesGtk.py", line 649, in on_isv_source_toggled self.backend.ToggleSourceUse(str(source_entry)) File "/usr/lib/python2.7/dist-packages/dbus/proxies.py", line 143, in __call__ **keywords) File "/usr/lib/python2.7/dist-packages/dbus/connection.py", line 630, in call_blocking message, timeout) dbus.exceptions.DBusException: com.ubuntu.SoftwareProperties.PermissionDeniedByPolicy: com.ubuntu.softwareproperties.applychanges Or from the muon package manager, an error dialog such as: Does anyone know what I need to do to fix this, so that I get a proper dialog asking for elevation? Otherwise, I have to start each app that may need root privs with sudo from a terminal or gksudo. Thanks

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• shutdown -i all computers in active directory domain

  - by Sihan Zheng

  I'm not sure if this is possible, but this is my goal: At the end of the day, I want to be able to turn off all the computers in the domain from a client. My account has sufficient privileges to shutdown any single computer remotely using shutdown -I, and I can RDP into any computer in the domain. However, is there an automated technique that does this? the computers in the domain are predictably named (computer1, computer2, etc), but than manipulating a list of 2000 computers in shutdown -I is pretty clumsy. Is there a way to shutdown every single computer in the domain from a single client? The domain server is windows 2003, and the clients all run windows xp thanks

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• Is there a name for a testing method where you compare a set of very different designs?

  - by DVK

  "A/B testing" is defined as "a method of marketing testing by which a baseline control sample is compared to a variety of single-variable test samples in order to improve response rates". The point here, of course, is to know which small single-variable changes are more optimal, with the goal of finding the local optimum. However, one can also envision a somewhat related but different scenario for testing the response rate of major re-designs: take a baseline control design, take one or more completely different designs, and run test samples on those redesigns to compare response rates. As a practical but contrived example, imagine testing a set of designs for the same website, one being minimalist "googly" design, one being cluttered "Amazony" design, and one being an artsy "designy" design (e.g. maximum use of design elements unlike Google but minimal simultaneously presented information, like Google but unlike Amazon) Is there an official name for such testing? It's definitely not A/B testing, since the main component of it (finding local optimum by testing single-variable small changes that can be attributed to response shift) is not present. This is more about trying to compare a set of local optimums, and compare to see which one works better as a global optimum. It's not a multivriable, A/B/N or any other such testing since you don't really have specific variables that can be attributed, just different designs.

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• HTTP Non-persistent connection and objects splitting

  - by Fabio Carello

  I hope this is the right board for my question about HTTP protocol with non-persistent connections. Suppose a single request for a html object that requires to be split in two different HTML response messages. My question is quite simple: do the connection will be closed after the first packet dispatch and then the other one will be sent on a new connection? I can't figure out if the non-persistent connection is applied at "single object level" (does't care if on multiples messages) or for every single message. Thanks for your answers!

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• Recommend Online password manager [closed]

  - by Dmitriy Nagirnyak

  Possible Duplicate: online password manager with sharing capabilities Hi, I am looking for a good online password manager with the following requirements: Single click login from browser. Single click form saving from the browser. Not attached to a single PC. Offline version (so I can use it if there is no internet, for example plug USB and have last sync-ed data). Ability to store plain text (notes, for example). Should work on Windows, Linux and Mac. So far I have been happy with RoboForm, but its offline USB version is not available on Linux. Please recommend. Thanks, Dmitriy.

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• SpriteBatch.end() generating null pointer exception

  - by odaymichael

  I am getting a null pointer exception using libGDX that the debugger points as the SpriteBatch.end() line. I was wondering what would cause this. Here is the offending code block, specifically the batch.end() line: batch.begin(); for (int j = 0; j < 3; j++) for (int i = 0; i < 3; i++) if (zoomgrid[i][j].getPiece().getImage() != null) zoomgrid[i][j].getPiece().getImage().draw(batch); batch.end(); The top of the stack is actually a line that calls lastTexture.bind(); In the flush() method of com.badlogic.gdx.graphics.g2d.SpriteBatch. I appreciate any input, let me know if I haven't included enough information.

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• Is rotating the lead developer a good or bad idea?

  - by Renesis

  I work on a team that has been flat organizationally since it's creation several months ago. My manager is non-technical and this means that our whole team is responsible for decision-making. My manager is beginning to realize that there are several benefits to having a lead developer, both for his sake (a single point of contact and single responsible party for tasks) and ours (dispute resolution, organized technical guidance, etc.). Because the team has been flat, one concern is that picking one lead developer may discourage the others. A non-developer suggested to my manager that rotating the lead developer is a possible way to avoid this issue. One developer would be lead one month, another the next, and so on. Is this a good idea? Why or why not? Keep in mind that this means all developers — All developers are good, but not necessarily equally suited to leadership. And if it is not, suppose I am likely the best candidate for lead developer — how do I recommend that we avoid this approach without looking like it's merely for selfish reasons? (In other words, the team is small enough that anyone recommending a single leader is likely to appear to be recommending themselves — especially those who have been part of the team longer.)

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• Using Delegates in C# (Part 1)

  - by rajbk

  This post provides a very basic introduction of delegates in C#. Part 2 of this post can be read here. A delegate is a class that is derived from System.Delegate.  It contains a list of one or more methods called an invocation list. When a delegate instance is “invoked” with the arguments as defined in the signature of the delegate, each of the methods in the invocation list gets invoked with the arguments. The code below shows example with static and instance methods respectively: Static Methods 1: using System; 2: using System.Linq; 3: using System.Collections.Generic; 4: 5: public delegate void SayName(string name); 6: 7: public class Program 8: { 9: [STAThread] 10: static void Main(string[] args) 11: { 12: SayName englishDelegate = new SayName(SayNameInEnglish); 13: SayName frenchDelegate = new SayName(SayNameInFrench); 14: SayName combinedDelegate =(SayName)Delegate.Combine(englishDelegate, frenchDelegate); 15: 16: combinedDelegate.Invoke("Tom"); 17: Console.ReadLine(); 18: } 19: 20: static void SayNameInFrench(string name) { 21: Console.WriteLine("J'ai m'appelle " + name); 22: } 23: 24: static void SayNameInEnglish(string name) { 25: Console.WriteLine("My name is " + name); 26: } 27: } We have declared a delegate of type SayName with return type of void and taking an input parameter of name of type string. On line 12, we create a new instance of this delegate which refers to a static method - SayNameInEnglish.  SayNameInEnglish has the same return type and parameter list as the delegate declaration.  Once a delegate is instantiated, the instance will always refer to the same target. Delegates are immutable. On line 13, we create a new instance of the delegate but point to a different static method. As you may recall, a delegate instance encapsulates an invocation list. You create an invocation list by combining delegates using the Delegate.Combine method (there is an easier syntax as you will see later). When two non null delegate instances are combined, their invocation lists get combined to form a new invocation list. This is done in line 14.  On line 16, we invoke the delegate with the Invoke method and pass in the required string parameter. Since the delegate has an invocation list with two entries, each of the method in the invocation list is invoked. If an unhandled exception occurs during the invocation of one of these methods, the exception gets bubbled up to the line where the invocation was made (line 16). If a delegate is null and you try to invoke it, you will get a System.NullReferenceException. We see the following output when the method is run: My name is TomJ'ai m'apelle Tom Instance Methods The code below outputs the same results as before. The only difference here is we are creating delegates that point to a target object (an instance of Translator) and instance methods which have the same signature as the delegate type. The target object can never be null. We also use the short cut syntax += to combine the delegates instead of Delegate.Combine. 1: public delegate void SayName(string name); 2: 3: public class Program 4: { 5: [STAThread] 6: static void Main(string[] args) 7: { 8: Translator translator = new Translator(); 9: SayName combinedDelegate = new SayName(translator.SayNameInEnglish); 10: combinedDelegate += new SayName(translator.SayNameInFrench); 11:  12: combinedDelegate.Invoke("Tom"); 13: Console.ReadLine(); 14: } 15: } 16: 17: public class Translator { 18: public void SayNameInFrench(string name) { 19: Console.WriteLine("J'ai m'appelle " + name); 20: } 21: 22: public void SayNameInEnglish(string name) { 23: Console.WriteLine("My name is " + name); 24: } 25: } A delegate can be removed from a combination of delegates by using the –= operator. Removing a delegate from an empty list or removing a delegate that does not exist in a non empty list will not result in an exception. Delegates are invoked synchronously using the Invoke method. We can also invoke them asynchronously using the BeginInvoke and EndInvoke methods which are compiler generated.

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• Critical Patch Update For Oracle Fusion Middleware - CPU October 2012

  - by Daniel Mortimer

  The latest Critical Patch Update (CPU) has been released for Oracle products. Start your reading hereCritical Patch Updates, Security Alerts and Third Party Bulletin  This is the home page containing links to all "Critical Patch Updates" released to date, along with sections detailing  Security Alerts  Third Party Bulletin Public Vulnerabilities Fixed Policies Reporting Security Vulnerabilities  On this page you will find the link to the Oracle Critical Patch Update Advisory - October 2012 The advisory lists the support documents that cover the patch availability for all Oracle products. From an Oracle Fusion Middleware perspective, you can cut to the chase by using the links below which take you to the appropriate sections inPatch Set Update and Critical Patch Update October 2012 Availability Document [ID 1477727.1] Oracle Fusion Middleware 11g Release 2  11.1.2.0 Oracle Fusion Middleware 11g Release 1 11.1.1.4 (Portal,Forms,Reports and Discoverer) 11.1.1.5 11.1.1.6 Oracle Application Server 10g Release 3 10.1.3.5 The #anchor links above should work in Firefox and IE provided you have already logged into My Oracle Support within the same browser session. For some reason, Chrome always takes you to the top of the document :-/ Tip: Error Correction Support for Oracle Identity Management 10g, version 10.1.4.x ended in December 2011. For this reason, there is no section which is specific to this version. However, Error Correction Support remains in place, until end of this year, for the Oracle Identity Management 10.1.4.x components Single Sign On (SSO) Delegated Administration Services (OIDDAS) provided you are using them as part of a Single Sign-On solution (OID 11g + SSO / OIDDAS 10.1.4.3) for a Portal / Forms / Reports and Discoverer 11.1.1.x architecture.    As such there are security related patches available for Fusion Middleware Single Sign On. You will find the patch numbers listed in the sections for 11.1.1.4, 11.1.1.5 and 11.1.1.6 And finally, if you are hit any unexpected errors when applying the CPU patches, check out the known issues documented in these two support documents. Critical Patch Update October 2012 Oracle Fusion Middleware Known Issues (Doc ID 1455408.1) Critical Patch Update October 2012 Database Known Issues (Doc ID 1477865.1)

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• install error wubi 12.10 rev273

  - by Doug

  Keep getting this error when installing wubi 12.10 rev273 11-09 14:16 ERROR TaskList: Error executing command command=C:\Windows\sysnative\bcdedit.exe /set {31400a42-f78f-11e0-9f68-e8757c793044} device partition=F: retval=1 stderr=An error has occurred setting the element data. The request is not supported. stdout= Traceback (most recent call last): File "\lib\wubi\backends\common\tasklist.py", line 197, in call File "\lib\wubi\backends\win32\backend.py", line 697, in modify_bcd File "\lib\wubi\backends\common\utils.py", line 66, in run_command Exception: Error executing command command=C:\Windows\sysnative\bcdedit.exe /set {31400a42-f78f-11e0-9f68-e8757c793044} device partition=F: retval=1 stderr=An error has occurred setting the element data. The request is not supported. Am trying to install in F drive Doug

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• Styles of games that work at low-resolution

  - by Brendan Long

  I'm taking a class on compilers, and the goal is to write a compiler for Meggy Jr devices (Arduino). The goal is just to make a simple compilers with loops and variables and stuff. Obviously, that's lame, so the "real goal" is to make an impressive game on the device. The problem is that it only has 64 pixels to work with (technically 72, but the top 8 are single-color and not part of the main display, so they're really only useful for displaying things like money). My problem is thinking of something to do on a device that small. It doesn't really matter if it's original, but it can't be something that's already available. My first idea was "snake", but that comes with the SDK. Same with a side-scrolling shooter. Remaining ideas include a tower defense game (hard to write, hard to control), an RPG (same), tetris (lame).. The problem is that all of the games I like require a high-resolution screen because they have a lot of text. Even a really simple game like nethack would be hard because each creature would be a single color. tl;dr What styles of games require a. No text; and b. Few enough objects that representing them each with a single color is acceptable? EDIT: To clarify, the display is 8x8 for a total of 64 pixels, not 64x64.

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• What's New in Database Lifecycle Management in Enterprise Manager 12c Release 3

  - by HariSrinivasan

  Enterprise Manager 12c Release 3 includes improvements and enhancements across every area of the product. This blog provides an overview of the new and enhanced features in the Database Lifecycle Management area. I will deep dive into specific features more in depth in subsequent posts. "What's New?"  In this release, we focused on four things: 1. Lifecycle Management Support for new Database12c - Pluggable Databases 2. Management of long running processes, such as a security patch cycle (Change Activity Planner) 3. Management of large number of systems by · Leveraging new framework capabilities for lifecycle operations, such as the new advanced ‘emcli’ script option · Refining features such as configuration search and compliance 4. Minor improvements and quality fixes to existing features · Rollback support for Single instance databases · Improved "OFFLINE" Patching experience · Faster collection of ORACLE_HOME configurations Lifecycle Management Support for new Database 12c - Pluggable Databases Database 12c introduces Pluggable Databases (PDBs), the brand new addition to help you achieve your consolidation goals. Pluggable databases offer unprecedented consolidation at database level and native lifecycle verbs for creating, plugging and unplugging the databases on a container database (CDB). Enterprise Manager can supplement the capabilities of pluggable databases by offering workflows for migrating, provisioning and cloning them using the software library and the deployment procedures. For example, Enterprise Manager can migrate an existing database to a PDB or clone a PDB by storing a versioned copy in the software library. One can also manage the planned downtime related to patching by  migrating the PDBs to a new CDB. While pluggable databases offer these exciting features, it can also pose configuration management and compliance challenges if not managed properly. Enterprise Manager features like inventory management, topology associations and configuration search can mitigate the sprawl of PDBs and also lock them to predefined golden standards using configuration comparison and compliance rules. Learn More ... Management of Long Running datacenter processes - Change Activity Planner (CAP) Currently, customers resort to cumbersome methods to create, execute, track and monitor change activities within their data center. Some customers use traditional tools such as spreadsheets, project planners and in-house custom built solutions. Customers often have weekly sync up meetings across stake holders to collect status and updates. Some of the change activities, for example the quarterly patch set update (PSU) patch rollouts are not single tasks but processes with multiple tasks. Some of those tasks are performed within Enterprise Manager Cloud Control (for example Patch) and some are performed outside of Enterprise Manager Cloud Control. These tasks often run for a longer period of time and involve multiple people or teams. Enterprise Manger Cloud Control supports core data center operations such as configuration management, compliance management, and automation. Enterprise Manager Cloud Control release 12.1.0.3 leverages these capabilities and introduces the Change Activity Planner (CAP). CAP provides the ability to plan, execute, and track change activities in real time. It covers the typical datacenter activities that are spread over a long period of time, across multiple people and multiple targets (even target types). Here are some examples of Change Activity Process in a datacenter: · Patching large environments (PSU/CPU Patching cycles) · Upgrading large number of database environments · Rolling out Compliance Rules · Database Consolidation to Exadata environments CAP provides user flows for Compliance Officers/Managers (incl. lead administrators) and Operators (DBAs and admins). Managers can create change activity plans for various projects, allocate resources, targets, and groups affected. Upon activation of the plan, tasks are created and automatically assigned to individual administrators based on target ownership. Administrators (DBAs) can identify their tasks and understand the context, schedules, and priorities. They can complete tasks using Enterprise Manager Cloud Control automation features such as patch plans (or in some cases outside Enterprise Manager). Upon completion, compliance is evaluated for validations and updates the status of the tasks and the plans. Learn More about CAP ...  Improved Configuration & Compliance Management of a large number of systems Improved Configuration Comparison:  Get to the configuration comparison results faster for simple ad-hoc comparisons. When performing a 1 to 1 comparison, Enterprise Manager will perform the comparison immediately and take the user directly to the results without having to wait for a job to be submitted and executed. Flattened system comparisons reduce comparison setup time and reduce complexity. In addition to the previously existing topological comparison, users now have an option to compare using a “flattened” methodology. Flattening means to remove duplicate target instances within the systems and remove the hierarchy of member targets. The result are much easier to spot differences particularly for specific use cases like comparing patch levels between complex systems like RAC and Fusion Apps. Improved Configuration Search & Advanced EMCLI Script option for Mass Automation Enterprise manager 12c introduces a new framework level capability to be able to script and stitch together multiple tasks using EMCLI. This powerful capability can be leveraged for lifecycle operations, especially when executing a task over a large number of targets. Specific usages of this include, retrieving a qualified list of targets using Configuration Search and then using the resultset for automation. Another example would be executing a patching operation and then re-executing on targets where it may have failed. This is complemented by other enhancements, such as a better usability for designing reusable configuration searches. IN EM 12c Rel 3, a simplified UI makes building adhoc searches even easier. Searching for missing patches is a common use of configuration search. This required the use of the advanced options which are now clearly defined and easy to use. Perform “Configuration Search” using the EMCLI. Users can find and execute Configuration Searches from the EMCLI which can be extremely useful for building sophisticated automation scripts. For an example, Run the Search named “Oracle Databases on Exadata” which finds all Database targets running on top of Exadata. Further filter the results by refining by options like name, host, etc.. emcli get_targets -config_search="Databases on Exadata" –target_name="exa%“ Use this in powerful mass automation operations using the new emcli script option. For example, to solve the use case of – Finding all DBs running on Exadata and housing E-Biz and Patch them. Create a Python script with emcli functions and invoke it in the new EMCLI script option shell. Invoke the script in the new EMCLI with script option directly: $<path to emcli>/emcli @myPSU_Patch.py Richer compliance content:  Now over 50 Oracle Provided Compliance Standards including new standards for Pluggable Database, Fusion Applications, Oracle Identity Manager, Oracle VM and Internet Directory. 9 Oracle provided Real Time Monitoring Standards containing over 900 Compliance Rules across 500 Facets. These new Real time Compliance Standards covers both Exadata Compute nodes and Linux servers. The result is increased Oracle software coverage and faster time to compliance monitoring on Exadata. Enhancements to Patch Management: Overhauled "OFFLINE" Patching experience: Simplified Patch uploads UI to improve the offline experience of patching. There is now a single step process to get the patches into software library. Customers often maintain local repositories of patches, sometimes called software depots, where they host the patches downloaded from My Oracle Support. In the past, you had to move these patches to your desktop then upload them to the Enterprise Manager's Software library through the Enterprise Manager Cloud Control user interface. You can now use the following EMCLI command to upload multiple patches directly from a remote location within the data center: $emcli upload_patches -location <Path to Patch directory> -from_host <HOSTNAME> The upload process filters all of the new patches, automatically selects the relevant metadata files from the location, and uploads the patches to software library. Other Improvements:  Patch rollback for single instance databases, new option in the Patch Plan to rollback the patches added to the patch plans. Upon execution, the procedure would rollback the patch and the SQL applied to the single instance Databases. Improved and faster configuration collection of Oracle Home targets can enable more reliable automation at higher level functions like Provisioning, Patching or Database as a Service. Just to recap, here is a list of database lifecycle management features:  * Red highlights mark – New or Enhanced in the Release 3. • Discovery, inventory tracking and reporting • Database provisioning including o Migration to Pluggable databases o Plugging and unplugging of pluggable databases o Gold image based cloning o Scaling of RAC nodes •Schema and data change management •End-to-end patch management in online and offline modes, including o Patch advisories in online (connected with My Oracle Support) and offline mode o Patch pre-deployment analysis, deployment and rollback (currently only for single instance databases) o Reporting • Upgrade planning and execution of the upgrade process • Configuration management including • Compliance management with out-of-box content • Change Activity Planner for planning, designing and tracking long running processes For more information on Enterprise Manager’s database lifecycle management capabilities, visit http://www.oracle.com/technetwork/oem/lifecycle-mgmt/index.html

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• Solving Big Problems with Oracle R Enterprise, Part II

  - by dbayard

  Part II – Solving Big Problems with Oracle R Enterprise In the first post in this series (see https://blogs.oracle.com/R/entry/solving_big_problems_with_oracle), we showed how you can use R to perform historical rate of return calculations against investment data sourced from a spreadsheet.  We demonstrated the calculations against sample data for a small set of accounts.  While this worked fine, in the real-world the problem is much bigger because the amount of data is much bigger.  So much bigger that our approach in the previous post won’t scale to meet the real-world needs. From our previous post, here are the challenges we need to conquer: The actual data that needs to be used lives in a database, not in a spreadsheet The actual data is much, much bigger- too big to fit into the normal R memory space and too big to want to move across the network The overall process needs to run fast- much faster than a single processor The actual data needs to be kept secured- another reason to not want to move it from the database and across the network And the process of calculating the IRR needs to be integrated together with other database ETL activities, so that IRR’s can be calculated as part of the data warehouse refresh processes In this post, we will show how we moved from sample data environment to working with full-scale data.  This post is based on actual work we did for a financial services customer during a recent proof-of-concept. Getting started with the Database At this point, we have some sample data and our IRR function.  We were at a similar point in our customer proof-of-concept exercise- we had sample data but we did not have the full customer data yet.  So our database was empty.  But, this was easily rectified by leveraging the transparency features of Oracle R Enterprise (see https://blogs.oracle.com/R/entry/analyzing_big_data_using_the).  The following code shows how we took our sample data SimpleMWRRData and easily turned it into a new Oracle database table called IRR_DATA via ore.create().  The code also shows how we can access the database table IRR_DATA as if it was a normal R data.frame named IRR_DATA. If we go to sql*plus, we can also check out our new IRR_DATA table: At this point, we now have our sample data loaded in the database as a normal Oracle table called IRR_DATA.  So, we now proceeded to test our R function working with database data. As our first test, we retrieved the data from a single account from the IRR_DATA table, pull it into local R memory, then call our IRR function.  This worked.  No SQL coding required! Going from Crawling to Walking Now that we have shown using our R code with database-resident data for a single account, we wanted to experiment with doing this for multiple accounts.  In other words, we wanted to implement the split-apply-combine technique we discussed in our first post in this series.  Fortunately, Oracle R Enterprise provides a very scalable way to do this with a function called ore.groupApply().  You can read more about ore.groupApply() here: https://blogs.oracle.com/R/entry/analyzing_big_data_using_the1 Here is an example of how we ask ORE to take our IRR_DATA table in the database, split it by the ACCOUNT column, apply a function that calls our SimpleMWRR() calculation, and then combine the results. (If you are following along at home, be sure to have installed our myIRR package on your database server via  “R CMD INSTALL myIRR”). The interesting thing about ore.groupApply is that the calculation is not actually performed in my desktop R environment from which I am running.  What actually happens is that ore.groupApply uses the Oracle database to perform the work.  And the Oracle database is what actually splits the IRR_DATA table by ACCOUNT.  Then the Oracle database takes the data for each account and sends it to an embedded R engine running on the database server to apply our R function.  Then the Oracle database combines all the individual results from the calls to the R function. This is significant because now the embedded R engine only needs to deal with the data for a single account at a time.  Regardless of whether we have 20 accounts or 1 million accounts or more, the R engine that performs the calculation does not care.  Given that normal R has a finite amount of memory to hold data, the ore.groupApply approach overcomes the R memory scalability problem since we only need to fit the data from a single account in R memory (not all of the data for all of the accounts). Additionally, the IRR_DATA does not need to be sent from the database to my desktop R program.  Even though I am invoking ore.groupApply from my desktop R program, because the actual SimpleMWRR calculation is run by the embedded R engine on the database server, the IRR_DATA does not need to leave the database server- this is both a performance benefit because network transmission of large amounts of data take time and a security benefit because it is harder to protect private data once you start shipping around your intranet. Another benefit, which we will discuss in a few paragraphs, is the ability to leverage Oracle database parallelism to run these calculations for dozens of accounts at once. From Walking to Running ore.groupApply is rather nice, but it still has the drawback that I run this from a desktop R instance.  This is not ideal for integrating into typical operational processes like nightly data warehouse refreshes or monthly statement generation.  But, this is not an issue for ORE.  Oracle R Enterprise lets us run this from the database using regular SQL, which is easily integrated into standard operations.  That is extremely exciting and the way we actually did these calculations in the customer proof. As part of Oracle R Enterprise, it provides a SQL equivalent to ore.groupApply which it refers to as “rqGroupEval”.  To use rqGroupEval via SQL, there is a bit of simple setup needed.  Basically, the Oracle Database needs to know the structure of the input table and the grouping column, which we are able to define using the database’s pipeline table function mechanisms. Here is the setup script: At this point, our initial setup of rqGroupEval is done for the IRR_DATA table.  The next step is to define our R function to the database.  We do that via a call to ORE’s rqScriptCreate. Now we can test it.  The SQL you use to run rqGroupEval uses the Oracle database pipeline table function syntax.  The first argument to irr_dataGroupEval is a cursor defining our input.  You can add additional where clauses and subqueries to this cursor as appropriate.  The second argument is any additional inputs to the R function.  The third argument is the text of a dummy select statement.  The dummy select statement is used by the database to identify the columns and datatypes to expect the R function to return.  The fourth argument is the column of the input table to split/group by.  The final argument is the name of the R function as you defined it when you called rqScriptCreate(). The Real-World Results In our real customer proof-of-concept, we had more sophisticated calculation requirements than shown in this simplified blog example.  For instance, we had to perform the rate of return calculations for 5 separate time periods, so the R code was enhanced to do so.  In addition, some accounts needed a time-weighted rate of return to be calculated, so we extended our approach and added an R function to do that.  And finally, there were also a few more real-world data irregularities that we needed to account for, so we added logic to our R functions to deal with those exceptions.  For the full-scale customer test, we loaded the customer data onto a Half-Rack Exadata X2-2 Database Machine.  As our half-rack had 48 physical cores (and 96 threads if you consider hyperthreading), we wanted to take advantage of that CPU horsepower to speed up our calculations.  To do so with ORE, it is as simple as leveraging the Oracle Database Parallel Query features.  Let’s look at the SQL used in the customer proof: Notice that we use a parallel hint on the cursor that is the input to our rqGroupEval function.  That is all we need to do to enable Oracle to use parallel R engines. Here are a few screenshots of what this SQL looked like in the Real-Time SQL Monitor when we ran this during the proof of concept (hint: you might need to right-click on these images to be able to view the images full-screen to see the entire image): From the above, you can notice a few things (numbers 1 thru 5 below correspond with highlighted numbers on the images above.  You may need to right click on the above images and view the images full-screen to see the entire image): The SQL completed in 110 seconds (1.8minutes) We calculated rate of returns for 5 time periods for each of 911k accounts (the number of actual rows returned by the IRRSTAGEGROUPEVAL operation) We accessed 103m rows of detailed cash flow/market value data (the number of actual rows returned by the IRR_STAGE2 operation) We ran with 72 degrees of parallelism spread across 4 database servers Most of our 110seconds was spent in the “External Procedure call” event On average, we performed 8,200 executions of our R function per second (110s/911k accounts) On average, each execution was passed 110 rows of data (103m detail rows/911k accounts) On average, we did 41,000 single time period rate of return calculations per second (each of the 8,200 executions of our R function did rate of return calculations for 5 time periods) On average, we processed over 900,000 rows of database data in R per second (103m detail rows/110s) R + Oracle R Enterprise: Best of R + Best of Oracle Database This blog post series started by describing a real customer problem: how to perform a lot of calculations on a lot of data in a short period of time.  While standard R proved to be a very good fit for writing the necessary calculations, the challenge of working with a lot of data in a short period of time remained. This blog post series showed how Oracle R Enterprise enables R to be used in conjunction with the Oracle Database to overcome the data volume and performance issues (as well as simplifying the operations and security issues).  It also showed that we could calculate 5 time periods of rate of returns for almost a million individual accounts in less than 2 minutes. In a future post, we will take the same R function and show how Oracle R Connector for Hadoop can be used in the Hadoop world.  In that next post, instead of having our data in an Oracle database, our data will live in Hadoop and we will how to use the Oracle R Connector for Hadoop and other Oracle Big Data Connectors to move data between Hadoop, R, and the Oracle Database easily.

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• Styles of games that work at low-resolution

  - by Brendan Long

  I'm taking a class on compilers, and the goal is to write a compiler for Meggy Jr devices (Arduino). The goal is just to make a simple compilers with loops and variables and stuff. Obviously, that's lame, so the "real goal" is to make an impressive game on the device. The problem is that it only has 64 pixels to work with (technically 72, but the top 8 are single-color and not part of the main display, so they're really only useful for displaying things like money). My problem is thinking of something to do on a device that small. It doesn't really matter if it's original, but it can't be something that's already available. My first idea was "snake", but that comes with the SDK. Same with a side-scrolling shooter. Remaining ideas include a tower defense game (hard to write, hard to control), an RPG (same), tetris (lame).. The problem is that all of the games I like require a high-resolution screen because they have a lot of text. Even a really simple game like nethack would be hard because each creature would be a single color. tl;dr What styles of games require a. No text; and b. Few enough objects that representing them each with a single color is acceptable?

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• Drawing on a webpage – HTML5 - IE9

  - by nmarun

  So I upgraded to IE9 and continued exploring HTML5. Now there’s this ‘thing’ called Canvas in HTML5 with which you can do some cool stuff. Alright what IS this Canvas thing anyways? The Web Hypertext Application Technology Working Group says this: “The canvas element provides scripts with a resolution-dependent bitmap canvas, which can be used for rendering graphs, game graphics, or other visual images on the fly.” The Canvas element has two only attributes – width and height and when not specified they take up the default values of 300 and 150 respectively. Below is what my HTML file looks like: 1: <!DOCTYPE html> 2: <html lang="en-US"> 3: <head> 4: <script type="text/javascript" src="CustomScript.js"></script> 5: <script src="jquery-1.4.4.js" type="text/javascript"></script 6:  7: <title>Draw on a webpage</title> 8: </head> 9: <body> 10: <canvas id="canvas" width="500" height="500"></canvas> 11: <br /> 12: <input type="submit" id="submit" value="Clear" /> 13: <h4 id="currentPosition"> 14: 0, 0 15: </h4> 16: <div id="mousedownCoords"></div> 17: </body> 18: </html> In case you’re wondering, this is not a MVC or any kind of web application. This is plain ol’ HTML even though I’m writing all this in VS 2010. You see this is a very simple, ‘gimmicks-free’ html page. I have declared a Canvas element on line 10 and a button on line 11 to clear the drawing board. I’m using jQuery / JavaScript show the current position of the mouse on the screen. This will get updated in the ‘currentPosition’ <h4> tag and I’m using the ‘mousedownCoords’ to write all the places where the mouse was clicked. This is what my page renders as: The rectangle with a background is our canvas. The coloring is due to some javascript (which we’ll see in a moment). Now let’s get to our CustomScript.js file. 1: jQuery(document).ready(function () { 2: var isFirstClick = true; 3: var canvas = document.getElementById("canvas"); 4: // getContext: Returns an object that exposes an API for drawing on the canvas 5: var canvasContext = canvas.getContext("2d"); 6: fillBackground(); 7:  8: $("#submit").click(function () { 9: clearCanvas(); 10: fillBackground(); 11: }); 12:  13: $(document).mousemove(function (e) { 14: $('#currentPosition').html(e.pageX + ', ' + e.pageY); 15: }); 16: $(document).mouseup(function (e) { 17: // on the first click 18: // set the moveTo 19: if (isFirstClick == true) { 20: canvasContext.beginPath(); 21: canvasContext.moveTo(e.pageX - 7, e.pageY - 7); 22: isFirstClick = false; 23: } 24: else { 25: // on subsequent clicks, draw a line 26: canvasContext.lineTo(e.pageX - 7, e.pageY - 7); 27: canvasContext.stroke(); 28: } 29:  30: $('#mousedownCoords').text($('#mousedownCoords').text() + '(' + e.pageX + ',' + e.pageY + ')'); 31: }); 32:  33: function fillBackground() { 34: canvasContext.fillStyle = '#a1b1c3'; 35: canvasContext.fillRect(0, 0, 500, 500); 36: canvasContext.fill(); 37: } 38:  39: function clearCanvas() { 40: // wipe-out the canvas 41: canvas.width = canvas.width; 42: // set the isFirstClick to true 43: // so the next shape can begin 44: isFirstClick = true; 45: // clear the text 46: $('#mousedownCoords').text(''); 47: } 48: })   The script only looks long and complicated, but is not. I’ll go over the main steps. Get a ‘hold’ of your canvas object and retrieve the ‘2d’ context out of it. On mousemove event, write the current x and y coordinates to the ‘currentPosition’ element. On mouseup event, check if this is the first time the user has clicked on the canvas. The coloring of the canvas is done in the fillBackground() function. We first need to start a new path. This is done by calling the beginPath() function on our context. The moveTo() function sets the starting point of our path. The lineTo() function sets the end point of the line to be drawn. The stroke() function is the one that actually draws the line on our canvas. So if you want to play with the demo, here’s how you do it. First click on the canvas (nothing visible happens on the canvas). The second click draws a line from the first click to the current coordinates and so on and so forth. Click on the ‘Clear’ button, to reset the canvas and to give your creativity a clean slate. Here’s a sample output: Happy drawing! Verdict: HTML5 and IE9 – I think we’re on to something big and great here!

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• Audigy 2 Coaxial to Coaxial/Optical connection possible?

  - by Chris

  Hello, The original question is deleted, and asked again below with accurate information. Edit: Excuse me for my ignorance, my friend has a Logitech Z-5500 set. I thought after comparing those systems on Google images that he had the Z-680, but he hasn't. This set has a single Digital coaxial for DVD or CD players or PC sound cards (requires coaxial cable, sold separately) cable. This single cable was connected to the orange tulip connector (SPDIF coaxial out) on the backside of his onboard HP Elite m9070, this connector is broken. How can I use the digital out with a single cable coaxial cable on the Audigy2 (see image below) (I have the following converters for my disposal, can I use one of these? 3.5 mm male - coax optical mini optical male - toslink optical female 2 x toslink optical female, toslink coupler, optical audio extension note: Is it possible to connect a toslink cable with an mini optical male - toslink converter on the digital out of the Audigy 2? (see image below)

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• e-Seminars para Parceiros - Maio 2010

  - by Claudia Costa

   A equipa de Alliances & Channels apresenta os novos e-Seminars para o mês de Maio. Para se inscrever nas formações que se encontram abaixo por favor utilize os links de registo indicados.     Nome Dia Duração Local Oracle Real-Time Decisions (RTD): Introduction to Oracle RTD   4 1 hora Início: 09h00 On-line Oracle Information Rights Management Overview   14 1 hora Início: 09h00 On-line Introduction to Oracle GoldenGate: Real -Time Data Integration and High Availability Solutions 21 1 hora Início: 09h00 On-line                                       

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• Which of these algorithms is best for my goal?

  - by JonathonG

  I have created a program that restricts the mouse to a certain region based on a black/white bitmap. The program is 100% functional as-is, but uses an inaccurate, albeit fast, algorithm for repositioning the mouse when it strays outside the area. Currently, when the mouse moves outside the area, basically what happens is this: A line is drawn between a pre-defined static point inside the region and the mouse's new position. The point where that line intersects the edge of the allowed area is found. The mouse is moved to that point. This works, but only works perfectly for a perfect circle with the pre-defined point set in the exact center. Unfortunately, this will never be the case. The application will be used with a variety of rectangles and irregular, amorphous shapes. On such shapes, the point where the line drawn intersects the edge will usually not be the closest point on the shape to the mouse. I need to create a new algorithm that finds the closest point to the mouse's new position on the edge of the allowed area. I have several ideas about this, but I am not sure of their validity, in that they may have far too much overhead. While I am not asking for code, it might help to know that I am using Objective C / Cocoa, developing for OS X, as I feel the language being used might affect the efficiency of potential methods. My ideas are: Using a bit of trigonometry to project lines would work, but that would require some kind of intense algorithm to test every point on every line until it found the edge of the region... That seems too resource intensive since there could be something like 200 lines that would have each have to have as many as 200 pixels checked for black/white.... Using something like an A* pathing algorithm to find the shortest path to a black pixel; however, A* seems resource intensive, even though I could probably restrict it to only checking roughly in one direction. It also seems like it will take more time and effort than I have available to spend on this small portion of the much larger project I am working on, correct me if I am wrong and it would not be a significant amount of code (100 lines or around there). Mapping the border of the region before the application begins running the event tap loop. I think I could accomplish this by using my current line-based algorithm to find an edge point and then initiating an algorithm that checks all 8 pixels around that pixel, finds the next border pixel in one direction, and continues to do this until it comes back to the starting pixel. I could then store that data in an array to be used for the entire duration of the program, and have the mouse re-positioning method check the array for the closest pixel on the border to the mouse target position. That last method would presumably execute it's initial border mapping fairly quickly. (It would only have to map between 2,000 and 8,000 pixels, which means 8,000 to 64,000 checked, and I could even permanently store the data to make launching faster.) However, I am uncertain as to how much overhead it would take to scan through that array for the shortest distance for every single mouse move event... I suppose there could be a shortcut to restrict the number of elements in the array that will be checked to a variable number starting with the intersecting point on the line (from my original algorithm), and raise/lower that number to experiment with the overhead/accuracy tradeoff. Please let me know if I am over thinking this and there is an easier way that will work just fine, or which of these methods would be able to execute something like 30 times per second to keep mouse movement smooth, or if you have a better/faster method. I've posted relevant parts of my code below for reference, and included an example of what the area might look like. (I check for color value against a loaded bitmap that is black/white.) // // This part of my code runs every single time the mouse moves. // CGPoint point = CGEventGetLocation(event); float tX = point.x; float tY = point.y; if( is_in_area(tX,tY, mouse_mask)){ // target is inside O.K. area, do nothing }else{ CGPoint target; //point inside restricted region: float iX = 600; // inside x float iY = 500; // inside y // delta to midpoint between iX,iY and tX,tY float dX; float dY; float accuracy = .5; //accuracy to loop until reached do { dX = (tX-iX)/2; dY = (tY-iY)/2; if(is_in_area((tX-dX),(tY-dY),mouse_mask)){ iX += dX; iY += dY; } else { tX -= dX; tY -= dY; } } while (abs(dX)>accuracy || abs(dY)>accuracy); target = CGPointMake(roundf(tX), roundf(tY)); CGDisplayMoveCursorToPoint(CGMainDisplayID(),target); } Here is "is_in_area(int x, int y)" : bool is_in_area(NSInteger x, NSInteger y, NSBitmapImageRep *mouse_mask){ NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init]; NSUInteger pixel[4]; [mouse_mask getPixel:pixel atX:x y:y]; if(pixel[0]!= 0){ [pool release]; return false; } [pool release]; return true; }

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