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• Second display is rotated

  - by pram

  I've just updated to Ubuntu 12.10 last night. When I was at the office, I connected my laptop with a projector. Although it can detect the projector, it incorrectly set the projector portrait. Also, if I click the Rotation dropdown, it has no Normal option. It only offered Anticlockwise and Clockwise options. Ofcourse the projector would display my desktop 90 degrees clockwise/anticlockwise. I've just test my laptop again with an LCD monitor, and it happened again. Below is my screenshot for display settings. My display adapter is Intel GMA 950. How to fix this problem?

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• Install a Mirror without downloading all packages from official repository

  - by Sam

  I first gonna explain the situation: I have a Laptop which is connected to a wifi connection, and a Desktop which can not be connected to Internet (the modem is too far from it), and i want to install some software on the last one. (The two PCs are running Ubuntu 12.04, and are connected with an Ethernet cable) I've already searched for a solution, but all I've found was the use of some softwares that should have been already installed on the "Internet-less PC". ( Keryx, APTonCD ... ) What I want to do is to create a mirror in my laptop which contain the packages i have in this one ( situated in /var/cache/apt/archive ) and i don't want to download all the packages from the official repository, I actually don't need them. Can someone tell me if it is possible to do that ? Thanks,

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• Gnome panel hides window titlebar.

  - by Xorty

  I moved my laptop screen "below" external screen (was using left/right config before). There's a little problem. When my gnome panel is on top of laptop screen, all windows I maximize "drawn" under top gnome panel. Therefore, I cannot see window titlebar. I tried suggested fixes as metacity --replace and so on, but none worked. When I move my taskbar to bottom it works just fine. Any ideas? Thank you.

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• Keyboard and touchpad do not work

  - by user289219

  I have an Lenovo IdeaPad S210 Touch and I want to install Ubuntu on it. The problem is that when I try booting the system from a USB drive (starting the so-called Live session) to try to see if the system works on my computer, the system will turn on and everything will work properly except for the keyboard and the touchpad. Neither of them are listed when using this command: xinput --list. I cannot get my laptop keyboard/touchpad to work, but USB keyboards and mice will work and my laptop's touchscreen will also work.

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• Kernel Panic Fatal Machine Check

  - by 0x4a6f4672

  I have got a new Samsung Series 7 laptop with dual boot setup for Windows 8 and Ubuntu 12.10. The Ubuntu installation was quite a hassle, but with the help of Boot Repair finally it seemed to work. Or so I thought. Windows 8 starts fine, but if I want to start Ubuntu regularly the following error occurs, quite similar to this one [Hardware Error] CPU 1: Machine Check Exception: 5 Bank 6 [Hardware Error] RIP !inexact! 33 <00007fab2074598a> [Hardware Error] TSC 95b623464c ADDR fe400 MISC 3880000086 .. [similar messages for CPU 2,3 and 0] .. [Hardware Error] Machine Check: Processor context corrupt Kernel panic - not syncing: Fatal Machine Check Rebooting in 30 seconds Kernel panic does not sound good. Then it starts to reboot, and the second boot trial often works. Is it a Kernel or driver problem? The laptop has an Intel Core i7 processor. I already deactivated Hyperthreading in the BIOS, but it does not seem to help :-(

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• Suspend fails (reboot on resume) and no hibernate option

  - by Matt Kibble

  Upgraded from 10.04 to 10.10 removed hibernate option for me and introduced the problem where by after entering standby (being indicated by blinking amber LED on my laptop) I cannot resume my session. Instead I get a crash and system reboots (crash comes instantly on trying to resume). Tried clean install to eliminate possibility of an upgrade issue but its still persistent. All latest updates installed. Tried looking for an answer to this but still no joy. Laptop is Sony VGN-FW41E.

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• HP 6735s Brightness hotkey problem; where is brightness panel?

  - by Paul

  I have installed ubuntu 11.10 on my laptop hp 6735s. The screen is often too dark and i want to make it brighter, although the hotkeys Fn+F7/F8 are not working. I have tried some things: Firstly it appears that sometimes they are in fact working, after reboot they either work and continue to do so or they don't. I've read about a brightness applet; but where can i find or install it? I have tried some grub options; acpi_osi=Linux and acpi_backlight=vendor but nothing changes. I don't want to add another question but since it might be related: my laptop also gets quite hot, i'm having doubts whether ubuntu connects to the available sensors and cooling plans (or how does it work???); sensors (or psensor) only shows 2 sensors both named temp1. Any help is greatly appreciated! Paul

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• StreamInsight 2.1, meet LINQ

  - by Roman Schindlauer

  Someone recently called LINQ “magic” in my hearing. I leapt to LINQ’s defense immediately. Turns out some people don’t realize “magic” is can be a pejorative term. I thought LINQ needed demystification. Here’s your best demystification resource: http://blogs.msdn.com/b/mattwar/archive/2008/11/18/linq-links.aspx. I won’t repeat much of what Matt Warren says in his excellent series, but will talk about some core ideas and how they affect the 2.1 release of StreamInsight. Let’s tell the story of a LINQ query. Compile time It begins with some code: IQueryable<Product> products = ...; var query = from p in products             where p.Name == "Widget"             select p.ProductID; foreach (int id in query) {     ... When the code is compiled, the C# compiler (among other things) de-sugars the query expression (see C# spec section 7.16): ... var query = products.Where(p => p.Name == "Widget").Select(p => p.ProductID); ... Overload resolution subsequently binds the Queryable.Where<Product> and Queryable.Select<Product, int> extension methods (see C# spec sections 7.5 and 7.6.5). After overload resolution, the compiler knows something interesting about the anonymous functions (lambda syntax) in the de-sugared code: they must be converted to expression trees, i.e.,“an object structure that represents the structure of the anonymous function itself” (see C# spec section 6.5). The conversion is equivalent to the following rewrite: ... var prm1 = Expression.Parameter(typeof(Product), "p"); var prm2 = Expression.Parameter(typeof(Product), "p"); var query = Queryable.Select<Product, int>(     Queryable.Where<Product>(         products,         Expression.Lambda<Func<Product, bool>>(Expression.Property(prm1, "Name"), prm1)),         Expression.Lambda<Func<Product, int>>(Expression.Property(prm2, "ProductID"), prm2)); ... If the “products” expression had type IEnumerable<Product>, the compiler would have chosen the Enumerable.Where and Enumerable.Select extension methods instead, in which case the anonymous functions would have been converted to delegates. At this point, we’ve reduced the LINQ query to familiar code that will compile in C# 2.0. (Note that I’m using C# snippets to illustrate transformations that occur in the compiler, not to suggest a viable compiler design!) Runtime When the above program is executed, the Queryable.Where method is invoked. It takes two arguments. The first is an IQueryable<> instance that exposes an Expression property and a Provider property. The second is an expression tree. The Queryable.Where method implementation looks something like this: public static IQueryable<T> Where<T>(this IQueryable<T> source, Expression<Func<T, bool>> predicate) {     return source.Provider.CreateQuery<T>(     Expression.Call(this method, source.Expression, Expression.Quote(predicate))); } Notice that the method is really just composing a new expression tree that calls itself with arguments derived from the source and predicate arguments. Also notice that the query object returned from the method is associated with the same provider as the source query. By invoking operator methods, we’re constructing an expression tree that describes a query. Interestingly, the compiler and operator methods are colluding to construct a query expression tree. The important takeaway is that expression trees are built in one of two ways: (1) by the compiler when it sees an anonymous function that needs to be converted to an expression tree, and; (2) by a query operator method that constructs a new queryable object with an expression tree rooted in a call to the operator method (self-referential). Next we hit the foreach block. At this point, the power of LINQ queries becomes apparent. The provider is able to determine how the query expression tree is evaluated! The code that began our story was intentionally vague about the definition of the “products” collection. Maybe it is a queryable in-memory collection of products: var products = new[]     { new Product { Name = "Widget", ProductID = 1 } }.AsQueryable(); The in-memory LINQ provider works by rewriting Queryable method calls to Enumerable method calls in the query expression tree. It then compiles the expression tree and evaluates it. It should be mentioned that the provider does not blindly rewrite all Queryable calls. It only rewrites a call when its arguments have been rewritten in a way that introduces a type mismatch, e.g. the first argument to Queryable.Where<Product> being rewritten as an expression of type IEnumerable<Product> from IQueryable<Product>. The type mismatch is triggered initially by a “leaf” expression like the one associated with the AsQueryable query: when the provider recognizes one of its own leaf expressions, it replaces the expression with the original IEnumerable<> constant expression. I like to think of this rewrite process as “type irritation” because the rewritten leaf expression is like a foreign body that triggers an immune response (further rewrites) in the tree. The technique ensures that only those portions of the expression tree constructed by a particular provider are rewritten by that provider: no type irritation, no rewrite. Let’s consider the behavior of an alternative LINQ provider. If “products” is a collection created by a LINQ to SQL provider: var products = new NorthwindDataContext().Products; the provider rewrites the expression tree as a SQL query that is then evaluated by your favorite RDBMS. The predicate may ultimately be evaluated using an index! In this example, the expression associated with the Products property is the “leaf” expression. StreamInsight 2.1 For the in-memory LINQ to Objects provider, a leaf is an in-memory collection. For LINQ to SQL, a leaf is a table or view. When defining a “process” in StreamInsight 2.1, what is a leaf? To StreamInsight a leaf is logic: an adapter, a sequence, or even a query targeting an entirely different LINQ provider! How do we represent the logic? Remember that a standing query may outlive the client that provisioned it. A reference to a sequence object in the client application is therefore not terribly useful. But if we instead represent the code constructing the sequence as an expression, we can host the sequence in the server: using (var server = Server.Connect(...)) {     var app = server.Applications["my application"];     var source = app.DefineObservable(() => Observable.Range(0, 10, Scheduler.NewThread));     var query = from i in source where i % 2 == 0 select i; } Example 1: defining a source and composing a query Let’s look in more detail at what’s happening in example 1. We first connect to the remote server and retrieve an existing app. Next, we define a simple Reactive sequence using the Observable.Range method. Notice that the call to the Range method is in the body of an anonymous function. This is important because it means the source sequence definition is in the form of an expression, rather than simply an opaque reference to an IObservable<int> object. The variation in Example 2 fails. Although it looks similar, the sequence is now a reference to an in-memory observable collection: var local = Observable.Range(0, 10, Scheduler.NewThread); var source = app.DefineObservable(() => local); // can’t serialize ‘local’! Example 2: error referencing unserializable local object The Define* methods support definitions of operator tree leaves that target the StreamInsight server. These methods all have the same basic structure. The definition argument is a lambda expression taking between 0 and 16 arguments and returning a source or sink. The method returns a proxy for the source or sink that can then be used for the usual style of LINQ query composition. The “define” methods exploit the compile-time C# feature that converts anonymous functions into translatable expression trees! Query composition exploits the runtime pattern that allows expression trees to be constructed by operators taking queryable and expression (Expression<>) arguments. The practical upshot: once you’ve Defined a source, you can compose LINQ queries in the familiar way using query expressions and operator combinators. Notably, queries can be composed using pull-sequences (LINQ to Objects IQueryable<> inputs), push sequences (Reactive IQbservable<> inputs), and temporal sequences (StreamInsight IQStreamable<> inputs). You can even construct processes that span these three domains using “bridge” method overloads (ToEnumerable, ToObservable and To*Streamable). Finally, the targeted rewrite via type irritation pattern is used to ensure that StreamInsight computations can leverage other LINQ providers as well. Consider the following example (this example depends on Interactive Extensions): var source = app.DefineEnumerable((int id) =>     EnumerableEx.Using(() =>         new NorthwindDataContext(), context =>             from p in context.Products             where p.ProductID == id             select p.ProductName)); Within the definition, StreamInsight has no reason to suspect that it ‘owns’ the Queryable.Where and Queryable.Select calls, and it can therefore defer to LINQ to SQL! Let’s use this source in the context of a StreamInsight process: var sink = app.DefineObserver(() => Observer.Create<string>(Console.WriteLine)); var query = from name in source(1).ToObservable()             where name == "Widget"             select name; using (query.Bind(sink).Run("process")) {     ... } When we run the binding, the source portion which filters on product ID and projects the product name is evaluated by SQL Server. Outside of the definition, responsibility for evaluation shifts to the StreamInsight server where we create a bridge to the Reactive Framework (using ToObservable) and evaluate an additional predicate. It’s incredibly easy to define computations that span multiple domains using these new features in StreamInsight 2.1! Regards, The StreamInsight Team

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• WMemoryProfiler is Released

  - by Alois Kraus

  What is it? WMemoryProfiler is a managed profiling Api to aid integration testing. This free library can get managed heap statistics and memory usage for your own process (remember testing) and other processes as well. The best thing is that it does work from .NET 2.0 up to .NET 4.5 in x86 and x64. To make it more interesting it can attach to any running .NET process. The reason why I do mention this is that commercial profilers do support this functionality only for their professional editions. An normally only since .NET 4.0 since the profiling API only since then does support attaching to a running process. This thing does differ in many aspects from “normal” profilers because while profiling yourself you can get all objects from all managed heaps back as an object array. If you ever wanted to change the state of an object which does only exist a method local in another thread you can get your hands on it now … Enough theory. Show me some code /// <summary> /// Show feature to not only get statisics out of a process but also the newly allocated /// instances since the last call to MarkCurrentObjects. /// GetNewObjects does return the newly allocated objects as object array /// </summary> static void InstanceTracking() { using (var dumper = new MemoryDumper()) // if you have problems use to see the debugger windows true,true)) { dumper.MarkCurrentObjects(); Allocate(); ILookup<Type, object> newObjects = dumper.GetNewObjects() .ToLookup( x => x.GetType() ); Console.WriteLine("New Strings:"); foreach (var newStr in newObjects[typeof(string)] ) { Console.WriteLine("Str: {0}", newStr); } } } … New Strings: Str: qqd Str: String data: Str: String data: 0 Str: String data: 1 … This is really hot stuff. Not only you can get heap statistics but you can directly examine the new objects and make queries upon them. When I do find more time I can reconstruct the object root graph from it from my own process. It this cool or what? You can also peek into the Finalization Queue to check if you did accidentally forget to dispose a whole bunch of objects … /// <summary> /// .NET 4.0 or above only. Get all finalizable objects which are ready for finalization and have no other object roots anymore. /// </summary> static void NotYetFinalizedObjects() { using (var dumper = new MemoryDumper()) { object[] finalizable = dumper.GetObjectsReadyForFinalization(); Console.WriteLine("Currently {0} objects of types {1} are ready for finalization. Consider disposing them before.", finalizable.Length, String.Join(",", finalizable.ToLookup( x=> x.GetType() ) .Select( x=> x.Key.Name)) ); } } How does it work? The W of WMemoryProfiler is a good hint. It does employ Windbg and SOS dll to do the heavy lifting and concentrates on an easy to use Api which does hide completely Windbg. If you do not want to see Windbg you will never see it. In my experience the most complex thing is actually to download Windbg from the Windows 8 Stanalone SDK. This is described in the Readme and the exception you are greeted with if it is missing in much greater detail. So I will not go into this here.   What Next? Depending on the feedback I do get I can imagine some features which might be useful as well Calculate first order GC Roots from the actual object graph Identify global statics in Types in object graph Support read out of finalization queue of .NET 2.0 as well. Support Memory Dump analysis (again a feature only supported by commercial profilers in their professional editions if it is supported at all) Deserialize objects from a memory dump into a live process back (this would need some more investigation but it is doable) The last item needs some explanation. Why on earth would you want to do that? The basic idea is to store in your live process some logging/tracing data which can become quite big but since it is never written to it is very fast to generate. When your process crashes with a memory dump you could transfer this data structure back into a live viewer which can then nicely display your program state at the point it did crash. This is an advanced trouble shooting technique I have not seen anywhere yet but it could be quite useful. You can have here a look at the current feature list of WMemoryProfiler with some examples.   How To Get Started? First I would download the released source package (it is tiny). And compile the complete project. Then you can compile the Example project (it has this name) and uncomment in the main method the scenario you want to check out. If you are greeted with an exception it is time to install the Windows 8 Standalone SDK which is described in great detail in the exception text. Thats it for the first round. I have seen something more limited in the Java world some years ago (now I cannot find the link anymore) but anyway. Now we have something much better.

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• Page Load Time - "Waiting on..." taking ages. What part of page request process is hung?

  - by James

  I have a new cluster site running on Magento that's on a development server that is made up of 2 x web servers and 1 x database server. I have optimized the site in all areas I know (gzip, increasing php memory limits, increasing database memory limits etc) but sometimes the page loading gets stuck on 'waiting for xxx.xx.xx.xxx' (Chrome and other broswers, chrome just shows it that way). It can sit there for 40 + seconds, sometimes it just never loads and I close it in frustration. What part of the page loading process is this hung at? Is it a server issue, database issue, platform issue? I need to know where to start or whether to push the hosting provider about it.

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• How can I generate signed distance fields (2D) in real time, fast?

  - by heishe

  In a previous question, it was suggested that signed distance fields can be precomputed, loaded at runtime and then used from there. For reasons I will explain at the end of this question (for people interested), I need to create the distance fields in real time. There are some papers out there for different methods which are supposed to be viable in real-time environments, such as methods for Chamfer distance transforms and Voronoi diagram-approximation based transforms (as suggested in this presentation by the Pixeljunk Shooter dev guy), but I (and thus can be assumed a lot of other people) have a very hard time actually putting them to use, since they're usually long, largely bloated with math and not very algorithmic in their explanation. What algorithm would you suggest for creating the distance fields in real-time (favourably on the GPU) especially considering the resulting quality of the distance fields? Since I'm looking for an actual explanation/tutorial as opposed to a link to just another paper or slide, this question will receive a bounty once it's eligible for one :-). Here's why I need to do it in real time: There's something else:

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• Install a Mirror without downloading all the packages in the official repository

  - by Sam

  I first gonna explain the situation : ( The two PCs are running Ubuntu 12.04 ) I have a Laptop which is connected to a wifi connection, and a Desktop which can not be connected to Internet ( the modem is too far from it ), and i want to install some software to the last one. ( the two PCs are connected with an Ethernet cable ) I've already searched for a solution, but all i found was the use of some softwares that should have been already installed on the "Internet-less PC". ( Keryx, APTonCD ... ) What I want to do is to create a mirror in my laptop which contain the packages i have in this one ( situated in /var/cache/apt/archive ) and i don't want to download all the packages from the official repository, I don't need them. Can someone tell me if this is possible ? Thank you.

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• Move Data into the Grid for Scalable, Predictable Response Times

  - by JuergenKress

  CloudTran is pleased to introduce the availability of the CloudTran Transaction and Persistence Manager for creating scalable, reliable data services on the Oracle Coherence In-Memory Data Grid (IMDG). Use of IMDG architectures has been key to handling today’s web-scale loads because it eliminates database latency by storing important and frequently access data in memory instead of on disk. The CloudTran product lets developers easily use an IMDG for full ACID-compliant transactions without having to be concerned about the location or spread of data. The system has its own implementation of fast, scalable distributed transactions that does NOT depend on XA protocols but still guarantees all ACID properties. Plus, CloudTran asynchronously replicates data going into the IMDG to back-end datastores and back-up data centers, again ensuring ACID properties. CloudTran can be accessed through Java Persistence API (JPA via TopLink Grid) and now, through a new Low-Level API, or LLAPI. This is ideal for use in SOA applications that need data reliability, high availability, performance, and scalability. Still in limited beta release, the LLAPI gives developers the ability to use standard put/remove logic available in Coherence and then wrap logic with simple Spring annotations or XML+AspectJ to start transactions. An important feature of LLAPI is the ability to join transactions. This is a common outcome for SOA applications that need to reduce network traffic by aggregating data into single cache entries and then doing SOA service processing in the node holding the data. This results in the need to orchestrate transaction processing across multiple service calls. CloudTran has the capability to handle these “multi-client” transactions at speed with no loss in ACID properties. Developing software around an IMDG like Oracle Coherence is an important choice for today’s web-scale applications and services. But this introduces new architectural considerations to maintain scalability in light of increased network loads and data movement. Without using CloudTran, developers are faced with an incredibly difficult task to ensure data reliability, availability, performance, and scalability when working with an IMDG. Working with highly distributed data that is entirely volatile while stored in memory presents numerous edge cases where failures can result in data loss. The CloudTran product takes care of all of this, leaving developers with the confidence and peace of mind that all data is processed correctly. For those interested in evaluating the CloudTran product and IMDGs, take a look at this link for more information: http://www.CloudTran.com/downloadAPI.php, or, send your questions to [email protected]. WebLogic Partner Community For regular information become a member in the WebLogic Partner Community please visit: http://www.oracle.com/partners/goto/wls-emea ( OPN account required). If you need support with your account please contact the Oracle Partner Business Center. BlogTwitterLinkedInMixForumWiki Technorati Tags: Coherence,cloudtran,cache,WebLogic Community,Oracle,OPN,Jürgen Kress

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• returning a heap block by reference in c++

  - by basicR

  I was trying to brush up my c++ skills. I got 2 functions: concat_HeapVal() returns the output heap variable by value concat_HeapRef() returns the output heap variable by reference When main() runs it will be on stack,s1 and s2 will be on stack, I pass the value by ref only and in each of the below functions, I create a variable on heap and concat them. When concat_HeapVal() is called it returns me the correct output. When concat_HeapRef() is called it returns me some memory address (wrong output). Why? I use new operator in both the functions. Hence it allocates on heap. So when I return by reference, heap will still be VALID even when my main() stack memory goes out of scope. So it's left to OS to cleanup the memory. Right? string& concat_HeapRef(const string& s1, const string& s2) { string *temp = new string(); temp->append(s1); temp->append(s2); return *temp; } string* concat_HeapVal(const string& s1, const string& s2) { string *temp = new string(); temp->append(s1); temp->append(s2); return temp; } int main() { string s1,s2; string heapOPRef; string *heapOPVal; cout<<"String Conact Experimentations\n"; cout<<"Enter s-1 : "; cin>>s1; cout<<"Enter s-2 : "; cin>>s2; heapOPRef = concat_HeapRef(s1,s2); heapOPVal = concat_HeapVal(s1,s2); cout<<heapOPRef<<" "<<heapOPVal<<" "<<endl; return -9; }

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• How can I make KDE faster in Ubuntu 12.04. It's very slow

  - by Rizwan Rifan

  I installed the kubuntu-desktop package in Ubuntu 12.04 LTS, but the problem is KDE responses very slowly. If I click on an application's icon to run it, it appears after 10 seconds and sometimes does not appear at all. It hangs all the time. The cursor is almost impossible to follow because of the lag. I have read on the Internet that Unity uses more memory and CPU than KDE. But on my PC Unity runs smoothly and KDE does not. So what should I do to make KDE as fast, responsive and smooth as Unity? My specifications are as follows: RAM: 1.5 GB (DDR2) Processor: 3 GHz Dual Core Graphics Card: Intel HD graphics with 256 MB memory.

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• interface changed after restart on Xubuntu

  - by Svetlana

  Something happened a few times after using Xubuntu since 1 month ago. A few times after i restarted my laptop the interface was totally changed. The icons from the panel were different and almost everything. It looked great, it had a grey interface, very nice icons, buttons were bigger and everything looked great. I have no idea what happened, i tried to find the same interface/theme from Settings Manager but without succes. Can anyone please tell me what happened or how can i use the grey interface? It dissapeared after i restarted the laptop. Thank you

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• How can I generate signed distance fields in real time, fast?

  - by heishe

  In a previous question, it was suggested that signed distance fields can be precomputed, loaded at runtime and then used from there. For reasons I will explain at the end of this question (for people interested), I need to create the distance fields in real time. There are some papers out there for different methods which are supposed to be viable in real-time environments, such as methods for Chamfer distance transforms and Voronoi diagram-approximation based transforms (as suggested in this presentation by the Pixeljunk Shooter dev guy), but I (and thus can be assumed a lot of other people) have a very hard time actually putting them to use, since they're usually long, largely bloated with math and not very algorithmic in their explanation. What algorithm would you suggest for creating the distance fields in real-time (favourably on the GPU) especially considering the resulting quality of the distance fields? Since I'm looking for an actual explanation/tutorial as opposed to a link to just another paper or slide, this question will receive a bounty once it's eligible for one :-). Here's why I need to do it in real time:

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• SQL 2014 does data the way developers want

  - by Rob Farley

  A post I’ve been meaning to write for a while, good that it fits with this month’s T-SQL Tuesday, hosted by Joey D’Antoni (@jdanton) Ever since I got into databases, I’ve been a fan. I studied Pure Maths at university (as well as Computer Science), and am very comfortable with Set Theory, which undergirds relational database concepts. But I’ve also spent a long time as a developer, and appreciate that that databases don’t exactly fit within the stuff I learned in my first year of uni, particularly the “Algorithms and Data Structures” subject, in which we studied concepts like linked lists. Writing in languages like C, we used pointers to quickly move around data, without a database in sight. Of course, if we had a power failure all this data was lost, as it was only persisted in RAM. Perhaps it’s why I’m a fan of database internals, of indexes, latches, execution plans, and so on – the developer in me wants to be reassured that we’re getting to the data as efficiently as possible. Back when SQL Server 2005 was approaching, one of the big stories was around CLR. Many were saying that T-SQL stored procedures would be a thing of the past because we now had CLR, and that obviously going to be much faster than using the abstracted T-SQL. Around the same time, we were seeing technologies like Linq-to-SQL produce poor T-SQL equivalents, and developers had had a gutful. They wanted to move away from T-SQL, having lost trust in it. I was never one of those developers, because I’d looked under the covers and knew that despite being abstracted, T-SQL was still a good way of getting to data. It worked for me, appealing to both my Set Theory side and my Developer side. CLR hasn’t exactly become the default option for stored procedures, although there are plenty of situations where it can be useful for getting faster performance. SQL Server 2014 is different though, through Hekaton – its In-Memory OLTP environment. When you create a table using Hekaton (that is, a memory-optimized one), the table you create is the kind of thing you’d’ve made as a developer. It creates code in C leveraging structs and pointers and arrays, which it compiles into fast code. When you insert data into it, it creates a new instance of a struct in memory, and adds it to an array. When the insert is committed, a small write is made to the transaction to make sure it’s durable, but none of the locking and latching behaviour that typifies transactional systems is needed. Indexes are done using hashes and using bw-trees (which avoid locking through the use of pointers) and by handling each updates as a delete-and-insert. This is data the way that developers do it when they’re coding for performance – the way I was taught at university before I learned about databases. Being done in C, it compiles to very quick code, and although these tables don’t support every feature that regular SQL tables do, this is still an excellent direction that has been taken. @rob_farley

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• Why wifi doesn't work in this case?

  - by xRobot

  I have a brand new notebook where I have installed Windows 7 and Ubuntu 12.04 LTS 64bit in dual boot. In windows 7 wifi works but in Ubuntu not. Could you help me please ? iwconfig lo no wireless extensions. wlan0 IEEE 802.11bgn ESSID:off/any Mode:Managed Access Point: Not-Associated Tx-Power=20 dBm Retry long limit:7 RTS thr:off Fragment thr:off Encryption key:off Power Management:off eth0 no wireless extensions. lshw -C network *-network description: Ethernet interface product: RTL8111/8168B PCI Express Gigabit Ethernet controller vendor: Realtek Semiconductor Co., Ltd. physical id: 0 bus info: pci@0000:01:00.0 logical name: eth0 version: 07 serial: b4:b5:1f:1b:9a:56 size: 10Mbit/s capacity: 1Gbit/s width: 64 bits clock: 33MHz capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=half firmware=rtl8168e-3_0.0.4 03/27/12 latency=0 link=no multicast=yes port=MII speed=10Mbit/s resources: irq:41 ioport:3000(size=256) memory:c2404000-c2404fff memory:c2400000-c2403fff *-network description: Wireless interface product: Ralink corp. vendor: Ralink corp. physical id: 0 bus info: pci@0000:02:00.0 logical name: wlan0 version: 00 serial: 84:4b:f4:0a:3a:22 width: 32 bits clock: 33MHz capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless configuration: broadcast=yes driver=rt2800pci driverversion=3.2.0-31-generic firmware=0.34 latency=0 link=no multicast=yes wireless=IEEE 802.11bgn resources: irq:18 memory:c2500000-c250ffff lspci | grep -i net 01:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 07) 02:00.0 Network controller: Ralink corp. Device 539a iwlist scan lo Interface doesn't support scanning. wlan0 Interface doesn't support scanning : Device or resource busy eth0 Interface doesn't support scanning. lsmod Module Size Used by rfcomm 47604 0 bnep 18281 2 bluetooth 180104 10 rfcomm,bnep parport_pc 32866 0 ppdev 17113 0 snd_hda_codec_hdmi 32474 1 snd_hda_codec_realtek 224173 1 joydev 17693 0 hp_wmi 18092 0 sparse_keymap 13890 1 hp_wmi snd_hda_intel 33773 3 snd_hda_codec 127706 3 snd_hda_codec_hdmi,snd_hda_codec_realtek,snd_hda_intel snd_hwdep 13668 1 snd_hda_codec snd_pcm 97188 3 snd_hda_codec_hdmi,snd_hda_intel,snd_hda_codec snd_seq_midi 13324 0 snd_rawmidi 30748 1 snd_seq_midi snd_seq_midi_event 14899 1 snd_seq_midi snd_seq 61896 2 snd_seq_midi,snd_seq_midi_event snd_timer 29990 2 snd_pcm,snd_seq snd_seq_device 14540 3 snd_seq_midi,snd_rawmidi,snd_seq psmouse 97362 0 snd 78855 16 snd_hda_codec_hdmi,snd_hda_codec_realtek,snd_hda_intel,snd_hda_codec,snd_hwdep,snd_pcm,snd_rawmidi,snd_seq,snd_timer,snd_seq_device arc4 12529 2 rt2800pci 18715 0 rt2800lib 58925 1 rt2800pci crc_ccitt 12667 1 rt2800lib rt2x00pci 14577 1 rt2800pci rt2x00lib 51144 3 rt2800pci,rt2800lib,rt2x00pci mac80211 506816 3 rt2800lib,rt2x00pci,rt2x00lib soundcore 15091 1 snd mac_hid 13253 0 uvcvideo 72627 0 videodev 98259 1 uvcvideo v4l2_compat_ioctl32 17128 1 videodev wmi 19256 1 hp_wmi i915 473240 3 cfg80211 205544 2 rt2x00lib,mac80211 eeprom_93cx6 12725 1 rt2800pci drm_kms_helper 46978 1 i915 drm 242038 4 i915,drm_kms_helper i2c_algo_bit 13423 1 i915 snd_page_alloc 18529 2 snd_hda_intel,snd_pcm mei 41616 0 serio_raw 13211 0 video 19596 1 i915 lp 17799 0 parport 46562 3 parport_pc,ppdev,lp usbhid 47199 0 hid 99559 1 usbhid r8169 62099 0 rfkill list: # rfkill list 0: phy0: Wireless LAN Soft blocked: no Hard blocked: no 1: hp-wifi: Wireless LAN Soft blocked: no Hard blocked: no

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• Failure to boot after suspending

  - by kosmonavt

  I have two issues with Ubuntu 12.04 (upgraded from 11.04, 11.10) on my ASUS K52De laptop. First issue: Booting fails, if it follows a suspension, then a wake-up and finally a shut down. If I realize this sequence, then, during the boot I see the Asus logo and after that I see only a blinking cursor instead of grub2. Then I have to recover grub2. Second issue: Sometimes, my laptop doesn't shut down. It freezes on the Ubuntu logo and I must turn it down with power buttom. Thank you.

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• Network Manager troubleshooting

  - by Anero

  I'm having some issues when connecting to my house's wifi from my Ubuntu 10.10 laptop. If the connection doesn't exists, when selecting the network (and after entering the WPA2 password) I'm able to connect. Once the connection is saved, when trying to reconnect, Network Manager works for a minute or so and then fails; the only way to reconnect then is to delete the saved connection and re-select the network from the list of available wireless networks. The same network works with no issues on the same laptop when running Win7, and on other wireless networks when running Ubuntu. Is there a Network Manager log which I can take a look at for troubleshooting the issue? Are there any tools for checking the wifi status?

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• Using static in PHP

  - by nischayn22

  I have a few functions in PHP that read data from functions in a class readUsername(int userId){ $reader = getReader(); return $reader->getname(userId); } readUserAddress(){ $reader = getReader(); return $reader->getaddress(userId); } All these make a call to getReader() { require_once("Reader.php"); static $reader = new Reader(); return $reader; } An overview of Reader class Reader{ getname(int id) { //if in-memory cache exists for this id return that //else get from db and cache it } getaddress(int id) { $this->getname(int id); //get address from name here } /*Other stuff*/ } Why is class Reader needed The Reader class does some in-memory caching of user details. So, I need only one object of class Reader and it will cache the user details instead of making multiple db calls. I am using static so that it the object gets created only once. Is this the right approach or should I do something else?

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• How to use only intel graphics and power off radeon?

  - by luizrogeriocn

  I've been using Linux for quite a while in everyday computing and programming. But now i got this new laptop with amazing battery life on windows which runs pretty cool even while gaming. But for some reason on Ubuntu I get like 1/3 battery life and it gets hot even while browsing the web. I have the proprietary drivers for radeon, but I'm thinking about upgrading from Ubuntu 12.04 to 14.04, and I would like to know how can I use only the Intel graphics and have radeon always turned off? Since I do not need the discrete graphics on Ubuntu and I'm pretty sure my problem is related to the radeon sucking up my battery and generating heat. My laptop technical specifications are: Dell latitude 3540 Intel core i7 4500U (with Intel hd4400 graphics ) Ati Radeon HD 8850m with 2GB GDDR5 VRAM 8 GB DDR3L @1600mhz Toshiba 256gb SSD Ubuntu 12.4.3 If you need any additional info, please tell me :)

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• No sound after clean install

  - by John Cheednik

  Did a clean install of Ubuntu 12.10 and everything working great except for the sound. Ubuntu doesn't even seem to be recognizing the fact my HP dv6000 has the capability of making sound! I have the dummy output problem, and when I try to open alsamixer using terminal I get the message that no such file or directory exists. I can't get it to recognize any soundcards or audio devices at all. I've been working on the problem for a couple days now and have even taken the laptop apart to ensure that all cables are properly attached... When I go into the PhoenixBIOS there are no sound options that I can find. The laptop does make a loud beep if I press buttons in the BIOS, but once it boots to the hard drive, the thing is mute. HELP!

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• Problem with Ubuntu and UEFI (Problem with any linux OS)

  - by K.T.Sumant

  I have purchased a new Sony Vaio laptop and it is said that the Windows in the recent laptops is installed in the UEFI mode. But all the Linux OS are installed in default in Legacy mode. When I reboot my laptop, Ubuntu is not being detected on boot. Only Windows is detected. To access Ubuntu, whenever I boot the system, I need to: (1) enter the boot menu, (2) change the mode to legacy, and (3) type a bit of scary commands in grub then Ubuntu successfully opens. This is a bit of problem for me. So I wanted to know the solution for this problem. So please kindly look over my problem as soon as possible.

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