ignore arguments - Page 178

Stuck due to "knowing too much"

- by Ran Biron

Note more discussion at http://news.ycombinator.com/item?id=4037794 Welcome Hacker News Visitors! While HN is a fine forum for discussion and debate, Programmers - Stack Exchange is not. From the FAQ: If your motivation for asking the question is “I would like to participate in a discussion about ____”, then you should not be asking here. However, if your motivation is “I would like others to explain ____ to me”, then you are probably OK. (Discussions are of course welcome in our real time web chat.) Currently, this question is viewed by the membership of Programmers.SE as more likely to provoke unproductive discussion than constructive answers; while debates on its form and future are conducted, it will be locked to prevent arguments and vandalism. -- Shog9 I have a relatively simple development task, but every time I try to attack it, I end up spiraling in deep thoughts - how could it extending the future, what are the 2nd generation clients going to need, how does it affect "non functional" aspects (e.g. Performance, authorization...), how would it best be architectured to allow change... I remember myself a while ago, younger and, perhaps, more eager. The "me" I was then wouldn't have given a thought about all that - he would've gone ahead and wrote something, then rewrote it, then rewrote it again (and again...). The "me" today is more hesitant, more careful. I find it much easier today to sit and plan and instruct other people on how to do things than to actually go ahead and do them myself - not because I don't like to code - the opposite, I love to! - but because every time I sit at the keyboard, I end up in that same annoying place. Is this wrong? Is this a natural evolution, or did I drive myself into a rut? Fair disclosure - in the past I was a developer, today my job title is a "system architect". Good luck figuring what it means - but that's the title. Wow. I honestly didn't expect this question to generate that many responses. I'll try to sum it up. Reasons: Analysis paralysis / Over engineering / gold plating / (any other "too much thinking up-front can hurt you"). Too much experience for the given task. Not focusing on what's important. Not enough experience (and realizing that). Solutions (not matched to reasons): Testing first. Start coding (+ for fun) One to throw away (+ one API to throw away). Set time constraints. Strip away the fluff, stay with the stuff. Make flexible code (kinda opposite to "one to throw away", no?). Thanks to everyone - I think the major benefit here was to realize that I'm not alone in this experience. I have, actually, already started coding and some of the too-big things have fallen off, naturally. Since this question is closed, I'll accept the answer with most votes as of today. When/if it changes - I'll try to follow.

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C# 4 Named Parameters for Overload Resolution

- by Steve Michelotti

C# 4 is getting a new feature called named parameters. Although this is a stand-alone feature, it is often used in conjunction with optional parameters. Last week when I was giving a presentation on C# 4, I got a question on a scenario regarding overload resolution that I had not considered before which yielded interesting results. Before I describe the scenario, a little background first. Named parameters is a well documented feature that works like this: suppose you have a method defined like this: 1: void DoWork(int num, string message = "Hello") 2: { 3: Console.WriteLine("Inside DoWork() - num: {0}, message: {1}", num, message); 4: } This enables you to call the method with any of these: 1: DoWork(21); 2: DoWork(num: 21); 3: DoWork(21, "abc"); 4: DoWork(num: 21, message: "abc"); and the corresponding results will be: Inside DoWork() - num: 21, message: Hello Inside DoWork() - num: 21, message: Hello Inside DoWork() - num: 21, message: abc Inside DoWork() - num: 21, message: abc This is all pretty straight forward and well-documented. What is slightly more interesting is how resolution is handled with method overloads. Suppose we had a second overload for DoWork() that looked like this: 1: void DoWork(object num) 2: { 3: Console.WriteLine("Inside second overload: " + num); 4: } The first rule applied for method overload resolution in this case is that it looks for the most strongly-type match first. Hence, since the second overload has System.Object as the parameter rather than Int32, this second overload will never be called for any of the 4 method calls above. But suppose the method overload looked like this: 1: void DoWork(int num) 2: { 3: Console.WriteLine("Inside second overload: " + num); 4: } In this case, both overloads have the first parameter as Int32 so they both fulfill the first rule equally. In this case the overload with the optional parameters will be ignored if the parameters are not specified. Therefore, the same 4 method calls from above would result in: Inside second overload: 21 Inside second overload: 21 Inside DoWork() - num: 21, message: abc Inside DoWork() - num: 21, message: abc Even all this is pretty well documented. However, we can now consider the very interesting scenario I was presented with. The question was what happens if you change the parameter name in one of the overloads. For example, what happens if you change the parameter *name* for the second overload like this: 1: void DoWork(int num2) 2: { 3: Console.WriteLine("Inside second overload: " + num2); 4: } In this case, the first 2 method calls will yield *different* results: 1: DoWork(21); 2: DoWork(num: 21); results in: Inside second overload: 21 Inside DoWork() - num: 21, message: Hello We know the first method call will go to the second overload because of normal method overload resolution rules which ignore the optional parameters. But for the second call, even though all the same rules apply, the compiler will allow you to specify a named parameter which, in effect, overrides the typical rules and directs the call to the first overload. Keep in mind this would only work if the method overloads had different parameter names for the same types (which in itself is weird). But it is a situation I had not considered before and it is one in which you should be aware of the rules that the C# 4 compiler applies.

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F1 Pit Pragmatics

- by mikef

"I hate computers. No, really, I hate them. I love the communications they facilitate, I love the conveniences they provide to my life. but I actually hate the computers themselves." - Scott Merrill, 'I hate computers: confessions of a Sysadmin' If Scott's goal was to polarize opinion and trigger raging arguments over the 'real reasons why computers suck', then he certainly succeeded. Impassioned vitriol sits side-by-side with rational debate. Yet Scott's fundamental point is absolutely on the money - Computers are a means to an end. The IT industry is finally starting to put weight behind the notion that good User Experience is an absolutely crucial goal, a cause championed by the likes of Microsoft's Bill Buxton, and which Apple's increasingly ubiquitous touch screen interface exemplifies. However, that doesn't change the fact that, occasionally, you just have to man up and deal with complex systems. In fact, sometimes you just need to sacrifice everything else in the name of performance. You'll find a perfect example of this Faustian bargain in Trevor Clarke's fascinating look into the (diabolical) IT infrastructure of modern F1 racing - high performance, high availability. high everything. To paraphrase, each car has up to 100 sensors, transmitting around 30Gb of data over the course of a race (70% in real-time). This data is then processed by no less than 3 servers (per car) so that the engineers in the pit have access to telemetry, strategy information, timing feeds, a connection back to the operations room in the team's home base - the list goes on. All of this while the servers are exposed "to carbon dust, oil, vibration, rain, heat, [and] variable power". Now, this is admittedly an extreme context where there's no real choice but to use complex systems where ease-of-use is, at best, a secondary concern. The flip-side is seen in small-scale personal computing such as that seen in Apple's iDevices, which are incredibly intuitive but limited in their scope. In terms of what kinds of systems they prefer to use, I suspect that most SysAdmins find themselves somewhere along this axis of Power vs. Usability, and which end of this axis you resonate with also hints at where you think the IT industry should focus its energy. Do you see yourself in the F1 pit, making split-second decisions, wrestling with information flows and reticent hardware to bend them to your will? If so, I imagine you feel that computers are subtle tools which need to be tuned and honed, using the advanced knowledge possessed only by responsible SysAdmins (If you have an iPhone, I suspect it's jail-broken). If the machines throw enigmatic errors, it's the price of flexibility and raw power. Alternatively, would you prefer to have your role more accessible, with users empowered by knowledge, spreading the load of managing IT environments? In that case, then you want hardware and software to have User Experience as their primary focus, and are of the "means to an end" school of thought (you're probably also fed up with users not listening to you when you try and help). At its heart, the dichotomy is between raw power (which might be difficult to use) and ease-of-use (which might have some limitations, but you can be up and running immediately). Of course, the ultimate goal is a fusion of flexibility, power and usability all in one system. It's achievable in specific software environments, and Red Gate considers it a target worth aiming for, but in other cases it's a goal right up there with cold fusion. I think it'll be a long time before we see it become ubiquitous. In the meantime, are you Power-Hungry or a Champion of Usability? Cheers, Michael Francis Simple Talk SysAdmin Editor

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Required Parameters [SSIS Denali]

- by jamiet

SQL Server Integration Services (SSIS) in its 2005 and 2008 incarnations expects you to set a property values within your package at runtime using Configurations. SSIS developers tend to have rather a lot of issues with SSIS configurations; in this blog post I am going to highlight one of those problems and how it has been alleviated in SQL Server code-named Denali. A configuration is a property path/value pair that exists outside of a package, typically within SQL Server or in a collection of one or more configurations in a file called a .dtsConfig file. Within the package one defines a pointer to a configuration that says to the package “When you execute, go and get a configuration value from this location” and if all goes well the package will fetch that configuration value as it starts to execute and you will see something like the following in your output log: Information: 0x40016041 at Package: The package is attempting to configure from the XML file "C:\Configs\MyConfig.dtsConfig". Unfortunately things DON’T always go well, perhaps the .dtsConfig file is unreachable or the name of the SQL Sever holding the configuration value has been defined incorrectly – any one of a number of things can go wrong. In this circumstance you might see something like the following in your log output instead: Warning: 0x80012014 at Package: The configuration file "C:\Configs\MyConfig.dtsConfig" cannot be found. Check the directory and file name. The problem that I want to draw attention to here though is that your package will ignore the fact it can’t find the configuration and executes anyway. This is really really bad because the package will not be doing what it is supposed to do and worse, if you have not isolated your environments you might not even know about it. Can you imagine a package executing for months and all the while inserting data into the wrong server? Sounds ridiculous but I have absolutely seen this happen and the root cause was that no-one picked up on configuration warnings like the one above. Happily in SSIS code-named Denali this problem has gone away as configurations have been replaced with parameters. Each parameter has a property called ‘Required’: Any parameter with Required=True must have a value passed to it when the package executes. Any attempt to execute the package will result in an error. Here we see that error when attempting to execute using the SSMS UI: and similarly when executing using T-SQL: Error is: Msg 27184, Level 16, State 1, Procedure prepare_execution, Line 112 In order to execute this package, you need to specify values for the required parameters. As you can see, SSIS code-named Denali has mechanisms built-in to prevent the problem I described at the top of this blog post. Specifying a Parameter required means that any packages in that project cannot execute until a value for the parameter has been supplied. This is a very good thing. I am loathe to make recommendations so early in the development cycle but right now I’m thinking that all Project Parameters should have Required=True, certainly any that are used to define external locations should be anyway. @Jamiet

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Do we still have a case against the goto statement? [closed]

- by FredOverflow

Possible Duplicate: Is it ever worthwhile using goto? In a recent article, Andrew Koenig writes: When asked why goto statements are harmful, most programmers will say something like "because they make programs hard to understand." Press harder, and you may well hear something like "I don't really know, but that's what I was taught." For that reason, I'd like to summarize Dijkstra's arguments. He then shows two program fragments, one without a goto and and one with a goto: if (n < 0) n = 0; Assuming that n is a variable of a built-in numeric type, we know that after this code, n is nonnegative. Suppose we rewrite this fragment: if (n >= 0) goto nonneg; n = 0; nonneg: ; In theory, this rewrite should have the same effect as the original. However, rewriting has changed something important: It has opened the possibility of transferring control to nonneg from anywhere else in the program. I emphasized the part that I don't agree with. Modern languages like C++ do not allow goto to transfer control arbitrarily. Here are two examples: You cannot jump to a label that is defined in a different function. You cannot jump over a variable initialization. Now consider composing your code of tiny functions that adhere to the single responsibility principle: int clamp_to_zero(int n) { if (n >= 0) goto n_is_not_negative: n = 0; n_is_not_negative: return n; } The classic argument against the goto statement is that control could have transferred from anywhere inside your program to the label n_is_not_negative, but this simply is not (and was never) true in C++. If you try it, you will get a compiler error, because labels are scoped. The rest of the program doesn't even see the name n_is_not_negative, so it's just not possible to jump there. This is a static guarantee! Now, I'm not saying that this version is better then the one without the goto, but to make the latter as expressive as the first one, we would at least have to insert a comment, or even better yet, an assertion: int clamp_to_zero(int n) { if (n < 0) n = 0; // n is not negative at this point assert(n >= 0); return n; } Note that you basically get the assertion for free in the goto version, because the condition n >= 0 is already written in line 1, and n = 0; satisfies the condition trivially. But that's just a random observation. It seems to me that "don't use gotos!" is one of those dogmas like "don't use multiple returns!" that stem from a time where the real problem were functions of hundreds or even thousand of lines of code. So, do we still have a case against the goto statement, other than that it is not particularly useful? I haven't written a goto in at least a decade, but it's not like I was running away in terror whenever I encountered one. 1 Ideally, I would like to see a strong and valid argument against gotos that still holds when you adhere to established programming principles for clean code like the SRP. "You can jump anywhere" is not (and has never been) a valid argument in C++, and somehow I don't like teaching stuff that is not true. 1: Also, I have never been able to resurrect even a single velociraptor, no matter how many gotos I tried :(

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Converting from mp4 to Xvid avi using avconv?

- by Ricardo Gladwell

I normally use avidemux to convert mp4s to Xvid AVI for my Philips Streamium SLM5500. Normally I select MPEG-4 ASP (Xvid) at Two Pass with an average bitrate f 1500kb/s for video and AC3 (lav) audio and it converts correctly. However, I'm trying to using avconv so I can automate the process with a script, but when I do this the video stutters and stops playing part way through. I have a suspicion its something to do with a faulty audio conversion. The commands I'm using are as follows: avconv -y -i video.mp4 -pass 1 -vtag xvid -c:a ac3 -b:a 128k -b:v 1500k -f avi /dev/null avconv -y -i video.mp4 -pass 2 -vtag xvid -c:a ac3 -b:a 128k -b:v 1500k -f avi video.avi There is a bewildering array of arguments for avconv. Is there something I'm doing wrong? Is there a way I can script avidemux from a headless server? Please see command line output: $ avconv -y -i video.mp4 -pass 1 -vtag xvid -an -b:v 1500k -f avi /dev/null avconv version 0.8.5-6:0.8.5-0ubuntu0.12.10.1, Copyright (c) 2000-2012 the Libav developers built on Jan 24 2013 14:49:20 with gcc 4.7.2 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'video.mp4': Metadata: major_brand : isom minor_version : 1 compatible_brands: isomavc1 creation_time : 2013-02-04 13:53:38 Duration: 00:44:09.16, start: 0.000000, bitrate: 669 kb/s Stream #0.0(und): Video: h264 (High), yuv420p, 720x404 [PAR 1:1 DAR 180:101], 538 kb/s, 25 fps, 25 tbr, 100 tbn, 50 tbc Metadata: creation_time : 2013-02-04 13:53:38 Stream #0.1(und): Audio: ac3, 44100 Hz, stereo, s16, 127 kb/s Metadata: creation_time : 2013-02-04 13:53:42 [buffer @ 0x7f4c40] w:720 h:404 pixfmt:yuv420p Output #0, avi, to '/dev/null': Metadata: major_brand : isom minor_version : 1 compatible_brands: isomavc1 creation_time : 2013-02-04 13:53:38 ISFT : Lavf53.21.1 Stream #0.0(und): Video: mpeg4, yuv420p, 720x404 [PAR 1:1 DAR 180:101], q=2-31, pass 1, 1500 kb/s, 25 tbn, 25 tbc Metadata: creation_time : 2013-02-04 13:53:38 Stream mapping: Stream #0:0 -> #0:0 (h264 -> mpeg4) Press ctrl-c to stop encoding frame=66227 fps=328 q=2.0 Lsize= 0kB time=2649.16 bitrate= 0.0kbits/s video:401602kB audio:0kB global headers:0kB muxing overhead -100.000000% $ avconv -y -i video.mp4 -pass 2 -vtag xvid -c:a ac3 -b:a 128k -b:v 1500k -f avi video.avi avconv version 0.8.5-6:0.8.5-0ubuntu0.12.10.1, Copyright (c) 2000-2012 the Libav developers built on Jan 24 2013 14:49:20 with gcc 4.7.2 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'video.mp4': Metadata: major_brand : isom minor_version : 1 compatible_brands: isomavc1 creation_time : 2013-02-04 13:53:38 Duration: 00:44:09.16, start: 0.000000, bitrate: 669 kb/s Stream #0.0(und): Video: h264 (High), yuv420p, 720x404 [PAR 1:1 DAR 180:101], 538 kb/s, 25 fps, 25 tbr, 100 tbn, 50 tbc Metadata: creation_time : 2013-02-04 13:53:38 Stream #0.1(und): Audio: ac3, 44100 Hz, stereo, s16, 127 kb/s Metadata: creation_time : 2013-02-04 13:53:42 [buffer @ 0x12b4f00] w:720 h:404 pixfmt:yuv420p Incompatible sample format 's16' for codec 'ac3', auto-selecting format 'flt' [mpeg4 @ 0x12b3ec0] [lavc rc] Using all of requested bitrate is not necessary for this video with these parameters. Output #0, avi, to 'video.avi': Metadata: major_brand : isom minor_version : 1 compatible_brands: isomavc1 creation_time : 2013-02-04 13:53:38 ISFT : Lavf53.21.1 Stream #0.0(und): Video: mpeg4, yuv420p, 720x404 [PAR 1:1 DAR 180:101], q=2-31, pass 2, 1500 kb/s, 25 tbn, 25 tbc Metadata: creation_time : 2013-02-04 13:53:38 Stream #0.1(und): Audio: ac3, 44100 Hz, stereo, flt, 128 kb/s Metadata: creation_time : 2013-02-04 13:53:42 Stream mapping: Stream #0:0 -> #0:0 (h264 -> mpeg4) Stream #0:1 -> #0:1 (ac3 -> ac3) Press ctrl-c to stop encoding Input stream #0:1 frame changed from rate:44100 fmt:s16 ch:2 to rate:44100 fmt:flt ch:2 frame=66227 fps=284 q=2.2 Lsize= 458486kB time=2649.13 bitrate=1417.8kbits/s video:413716kB audio:41393kB global headers:0kB muxing overhead 0.741969%

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Unit Testing Framework for XQuery

- by Knut Vatsendvik

This posting provides a unit testing framework for XQuery using Oracle Service Bus. It allows you to write a test case to run your XQuery transformations in an automated fashion. When the test case is run, the framework returns any differences found in the response. The complete code sample with install instructions can be downloaded from here. Writing a Unit Test You start a new Test Case by creating a Proxy Service from Workshop that comes with Oracle Service Bus. In the General Configuration page select Service Type to be Messaging Service In the Message Type Configuration page link both the Request & Response Message Type to the TestCase element of the UnitTest.xsd schema The TestCase element consists of the following child elements The ID and optional Name element is simply used for reference. The Transformation element is the XQuery resource to be executed. The Input elements represents the input to run the XQuery with. The Output element represents the expected output. These XML documents are “also” represented as an XQuery resource where the XQuery function takes no arguments and returns the XML document. Why not pass the test data with the TestCase? Passing an XML structure in another XML structure is not very easy or at least not very human readable. Therefore it was chosen to represent the test data as an loadable resource in the OSB. However you are free to go ahead with another approach on this if wanted. The XMLDiff elements represents any differences found. A sample on input is shown here. Modeling the Message Flow Then the next step is to model the message flow of the Proxy Service. In the Request Pipeline create a stage node that loads the test case input data. For this, specify a dynamic XQuery expression that evaluates at runtime to the name of a pre-registered XQuery resource. The expression is of course set by the input data from the test case. Add a Run stage node. Assign the result of the XQuery, that is to be run, to a context variable. Define a mapping for each of the input variables added in previous stage. Add a Compare stage. Like with the input data, load the expected output data. Do a compare using XMLDiff XQuery provided where the first argument is the loaded output test data, and the second argument the result from the Run stage. Any differences found is replaced back into the test case XMLDiff element. In case of any unexpected failure while processing, add an Error Handler to the Pipeline to capture the fault. To pass back the result add the following Insert action In the Response Pipeline. A sample on output is shown here.

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Deploy Oracle Management Agent using RPM File

- by cristiano.toni

Normal 0 21 false false false EN-US JA X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tableau Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times","serif"; mso-ansi-language:FR;} 1) Create a rpm package on Enterprise Manager 12c a) as Root : # yum install rpmbuild # mkdir /usr/lib/oracle b) as oracle user # cd $<OMS_HOME>/bin/ # emcli get_supported_platforms ----------------------------------------------- Version = 12.1.0.3.0 Platform = Linux x86-64 ----------------------------------------------- Platforms list displayed successfully. # emcli get_agentimage_rpm -destination=/tmp/agentRPM -platform="Linux x86-64" \ -version=12.1.0.3.0 Platform:Linux x86-64 Destination:/tmp/agentRPM Exalogic:false Checking for disk space requirements... === Partition Detail === Space free : 6 GB Space required : 1 GB RPM creation in progress ... Check the logs at /Oracle/gc_inst/em/EMGC_OMS1/sysman/emcli/setup/.emcli/get_agentimage_rpm_date-PM.log Copying agent image from software library to /tmp/agentRPM Setting property ORACLE_HOME to:/Oracle/middleware/oms calling pulloneoffs with arguments:/Oracle/middleware/oms/Oracle/middleware/oms/sysman/agent/ \ 12.1.0.3.0_AgentCore_226.zip12.1.0.3.0Linux x86-64/tmp/agentRPMtrue Agent Image copied successfully... Creation of RPM started... RPM creation successful. Agent image to rpm conversion completed successfully 2) Copy it on all new hosts and install it. As Root user : c) check and install rpm file # rpm -ivh --test oracle-agt-12.1.0.3.0-1.0.x86_64.rpm Preparing... ########################################### [100%] # rpm -ivh oracle-agt-12.1.0.3.0-1.0.x86_64.rpm Preparing... ########################################### [100%] Running the prereq 1:oracle-agt ########################################### [100%] Agent RPM installation is completed successfully. Now to configure the agent follow the below steps: 1. Edit the properties file: /usr/lib/oracle/agent/agent.properties with the correct values 2. Execute the script /etc/init.d/oracle-agt RESPONSE_FILE=/usr/lib/oracle/agent/agent.properties d) create a user for the agent: # useradd -m -d /home/em12adm -s /bin/bash -g dba -G oinstall em12adm # passwd em12adm e) Edit file /usr/lib/oracle/agent/agent.properties # vi /usr/lib/oracle/agent/agent.properties OMS_HOST=<host_Enterprise_Manager> OMS_PORT=<HTTPS Upload Port > AGENT_REGISTRATION_PASSWORD=oracle AGENT_USERNAME=em12adm AGENT_GROUP=dba ORACLE_HOSTNAME=oraclevm-mgmt # chown -R em12adm:dba /usr/lib/oracle/agent/ Start agent and register the new host server on EM12c # /etc/init.d/oracle-agt RESPONSE_FILE=/usr/lib/oracle/agent/agent.properties Now you have registered on EM12C your new target host.

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Windows Phone 8, possible tablets and what the latest update might mean

- by Roger Hart

Microsoft have just announced an update to Windows Phone 8. As one of the five, maybe six people who actually bought a WP8 handset I found this interesting. Then I read the blog post about it, and rushed off to write somewhat less than a thousand words about a single picture. The blog post announces an extra column of tiles on the start screen, and support for higher resolutions. If we ignore all the usual flummery about how this will make your life better, that (and the rotation lock) sounds a little like stage setting for tablets. Looking at the preview screenshot, I started to wonder. What it’s called Phablet_5F00_StartScreenProductivity_5F00_01_5F00_072A1240.jpg Pretty conclusive. If you can brand something a “phablet” and sleep at night you’re made of sterner stuff than I am, but that’s beside the point. It’s explicit in the post that Microsoft are expecting a broader range of form factors for WP8, but they stop short of quite calling out tablet size. The extra columns and resolution definitely back that up, so why stop at a 6 inch “phablet”? Sadly, the string of numbers there don’t really look like a Lumia model number – that would be a bit tendentious even for a speculative blog post about a single screenshot. “Productivity” is interesting too. I get into this a bit more below, but this is a pretty clear pitch for a business device. What it looks like Something that would look quite decent on a 7 inch screen, but something a bit too vertical to go toe-to-toe with the Surface. Certainly, it would look a lot better on a large-factor phone than any of the current models. Those tiles are going to get cramped and a bit ugly if the handsets aren’t getting bigger. What’s on it You have a bunch of missed calls, you rarely text, use a stocks app, and your budget spreadsheet and meeting notes are a thumb-reach away. Outlook is your main form of email. You care enough about LinkedIn to not only install its app but give it a huge live tile. There’s no beating about the bush here, the implicit persona is a corporate exec. With Nokia in the bag and Blackberry pushing daisies, that may not be a stupid play. There’s almost certainly a niche there if they can parlay their corporate credentials into filling it before BYOD (which functionally means an iPhone) reaches the late adopters. The really quite slick WP8 Office implementation ought to help here. This is the face they’ve chosen to present, the cultural milieu they’re normalizing for Windows Phone. It’s an iPhone for Serious Business Grown-ups. Could work, I guess. Does it mean anything? Is the latest WP8 update a sign that we can expect to see tablets running Windows Phone rather than WinRT? Well, WinRT tablets haven’t exactly taken off but I’m not quite going to make a leap like that just from a file name and a column of icons. I feel pretty safe, however, conjecturing that Microsoft would like to squeeze a WP8 “phablet” into the palm of every exec who’s ever grumbled about their Blackberry, and this release might get them a bit closer. If it works well incrementing up to larger devices, then that could be a fair hedge against WinRt crashing and burning any harder in the marketplace.

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Tweaking Remote Control (In-Kernel LIRC)

- by Geoff

I've recently rebuilt my MythTV box using Mythbuntu 12.04, to take advantage of newer hardware (Ivy Bridge). On my previous build I used lirc to manage the remote, i.e. the mapping of key codes - keypresses - application keys; it was quite a journey to learn it all, and I ended up fairly comfortable with how it all worked. What I have: I have a cheap Chinavasion remote and USB dongle, which I've found several articles on; these largely revolve around working with XBMC (interesting, but I don't think directly applicable) and also around getting a Harmony remote to work (it's a Chinavasion CVSB-983 - very useful, since I needed this to get my Harmony 900 working). Mythbuntu 12.04 64-bit MythTV 0.25 (likely irrelevant) How it is right now When I plug this in, it 'just works'. Which is great, except that Ubuntu uses it natively, and prevents some of the button presses from getting through to Myth. For example, I can send a button from the remote that equates to Ctrl-Alt-A (which I assume Ubuntu isn't interested in), and then trap that in Mythfrontend, but the remote's Play button is caught by Ubuntu (which displays a large circle with a line though it, as there's no media player loaded). I understand that this is because lirc is merged into the kernel now, and I like that. What I've done so far: Found the device using lsusb: $ lsusb Bus 001 Device 004: ID 073a:2230 Chaplet Systems, Inc. infrared dongle for remote Found the event device number: $ cat /proc/bus/input/devices I: Bus=0003 Vendor=073a Product=2230 Version=0110 N: Name="HID 073a:2230" P: Phys=usb-0000:00:1a.0-1.2/input0 S: Sysfs=/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.2/1-1.2:1.0/input/input5 U: Uniq= H: Handlers=sysrq kbd mouse1 event5 js0 B: PROP=0 B: EV=10001f B: KEY=4c37fff072ff32d bf54445600000000 ffffffffff 30c100b17c007 ffa67bfad951dfff febeffdfffefffff fffffffffffffffe B: REL=343 B: ABS=100030000 B: MSC=10 Tested the input with evtest (I pressed Play): $ sudo evtest /dev/input/event5 Input driver version is 1.0.1 Input device ID: bus 0x3 vendor 0x73a product 0x2230 version 0x110 Input device name: "HID 073a:2230" Supported events: Event type 0 (EV_SYN) Event type 1 (EV_KEY) Event code 1 (KEY_ESC) Event code 2 (KEY_1) Event code 3 (KEY_2) Event code 4 (KEY_3) Event code 5 (KEY_4) Event code 6 (KEY_5) Event code 7 (KEY_6) <------------snipped lots of 'Event code' lines------------> Testing ... (interrupt to exit) Event: time 1336435683.230656, -------------- SYN_REPORT ------------ Event: time 1336435683.246648, type 4 (EV_MSC), code 4 (MSC_SCAN), value c00cd Event: time 1336435683.246652, type 1 (EV_KEY), code 164 (KEY_PLAYPAUSE), value 0 Event: time 1336435683.246655, -------------- SYN_REPORT ------------ Tested showkey, again for the Play key: $ sudo showkey -s kb mode was RAW [ if you are trying this under X, it might not work since the X server is also reading /dev/console ] press any key (program terminates 10s after last keypress)... 0xe0 0x22 0xe0 0xa2 What I want: I'd like a way to scan the incoming button presses, if the above method isn't correct. I'd like to either remap each button press to something that Ubuntu/Unity will ignore, or even better pass the keypress directly to Myth (I suspect this later is only possible with lirc, but I could be wrong). I would really like to do this with the in-kernel drivers, i.e. without explicitly loading lirc; if that's the way the world is going, I'd rather find a way to map the current behaviour to what I want, rather than forcing the 'old' arrangement of loading lirc outside the kernel. Learning something new is also worthwhile! My guess: I'm assuming that this will require using setkeycodes, but have had trouble finding enough information to configure this. Any help greatly appreciated!

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SharePoint 2013 Developer Ramp-Up - Part 1

Today I had a little spare time during the morning hours and I decided that after checking MVA that I'm going to query the available course material over at Pluralsight. Wow, thanks to fantastic corporations and acquisitions there are lots of courses available. Nicely split by SharePoint version as well as particular interest group. Additionally, I found a couple of online blogs and community sites that I'm going to visit regularly during the next couple of weeks. Today's resource(s) Of course, I'm "all in" for the latest developer resources: SharePoint 2013 Developer Ramp-Up - Part 1 - Understanding the Platform and Developer Experience SharePoint 2013 Developer Ramp-Up - Part 2 SharePoint 2013 Developer Ramp-Up - Part 3 SharePoint 2013 Developer Ramp-Up - Part 4 SharePoint 2013 Developer Ramp-Up - Part 5 SharePoint 2013 Developer Ramp-Up - Part 6 I guess, I'm going to stick to the Pluralsight library until the end of this week. We'll see... Anyway, apart from the video material I came across a couple of other websites which I'd like to list here, too. That's mainly for personal reference instead of bookmarking in the browser, I'll use my own blog for that purpose. Atkinson's SharePoint Blog Düsseldorfer Jung Doerflers SharePoint Blog SharePoint Community Absolute SharePoint The links are in no preferential order and I added them as soon as I found them. Most probably, I'm going to report about specific articles from those resources during this challenge. So, stay tuned and I try to provide more details on certain topics. Takeaway First contact with the 'real stuff' in order to get an idea about software development in Microsoft SharePoint and beyond. Unfortunately and as already expected, the marketing department over at Microsoft seemed to have nothing better to do than to invent new names and baptise literally the same product with every release. Luckily, the release cycles between versions have been three years (roughly) - 2007, 2010, and 2013. Nonetheless, there will be a lot of version-specfic issues to tackle during this learning phase. Especially, when it's about historical expressions like 'WSS'* like I had it yesterday... It's going to be exciting and demanding to catch up with roughly 6-7 years of development and changes. Okay, let's face it. * WSS stands for Windows SharePoint Services 3.0 which forms the 'core engine' of SharePoint 2007. Part 1 of Andrew Connell's series on SharePoint 2013 for developers provides a brief history and overview of the various product names and their relation to the actual SharePoint version. I guess, I might create a cheat-sheet or something comparable in order to reduce the level of confusion while reading through other material: SharePoint 2007 (aka SharePoint v3 aka SharePoint 12) Windows SharePoint Services (WSS) 3.0 Microsoft Office SharePoint Server (MOSS) 2007 .NET Framework 3.0, 32-bit or 64-bit OS SharePoint 2010 (aka SharePoint v4 aka SharePoint 14) Microsoft SharePoint Foundation (SPF) 2010 Microsoft SharePoint Server (SPS) 2010 .NET Framework 3.5 SP1, 64-bit OS only SharePoint 2013 Microsoft SharePoint Foundation (SPF) 2013 Microsoft SharePoint Server (SPS) 2013 .NET Framework 4.5, 64-bit OS only After this quick excursion it is getting more interesting. SharePoint 2013 has a number of Development Practices and Techniques under the hood, and it will be quite a decision process depending on the task requirements to choose the correct path to go. At the moment, the following two options seem to be my future fields of operation: Client-Side Object Model (CSOM) REST API and OData syntax As part of my job assignment, I see myself developing within Visual Studio 2012/2013. Most probably the client development in C# will be using CSOM but of course I'll keep an eye on the REST API, too. JavaScript has quite a momentum since a while and it would a shame to ignore this type of opportunity and possibilities.

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MPI Cluster Debugger launch integration in VS2010

Let's assume that you have all the HPC bits installed and that you have existing MPI code (or you created a "Hello World" project using the MPI project template). Of course, you create a single MPI application and at runtime it will correspond to multiple processes (of the same app) launched on multiple nodes (i.e. machines) on the cluster. So how do you debug such a situation by simply hitting the familiar "F5" keystroke (i.e. Debug - Start Debugging)?WATCH IT INSTEAD OF READING ABOUT ITIf you can't bear to read through all the details below, just watch this 19-minute screencast explaining this VS2010 feature. Alternatively, or even additionally, keep on reading.REQUIREMENTWhen you debug an MPI application, you would want the copying of resources from your client machine (where Visual Studio is installed) to each compute node (where Windows HPC Server is installed) to take place automatically for you. 'Resources' in the previous sentence includes your application binary, plus any binary or data dependencies it may have, plus PDBs if needed, plus the debug CRT of the correct bitness, plus msvsmon for remote debugging to work. You would also want, after copying is complete, to have your app and msvsmon launched and attached so that you can hit breakpoints back in Visual Studio on your client machine. All these thing that you would want are delivered in VS2010.STEPS TO F51. In your MPI project where you have placed a breakpoint go to Project Properties - Configuration Properties - Debugging. Ensure the "Debugger to launch" combo box value is set to MPI Cluster Debugger.2. There are a whole bunch of properties here and typically you can ignore all of them except one: Run Environment. By default it is set to run 1 process on your local machine and if you change the number after that to, for example, 4 it will launch 4 processes of your app on your local machine.You want this to run on your cluster though, so go to the dropdown arrow at the end of the Run Environment cell and open it to expose the "Edit Hpc node" menu which opens the Node Selector dialog:In this dialog you can enter (or pick from a list) the cluster head node name and then the number of processes you want to execute on the cluster and then hit OK and… you are done.3. Press F5 and watch your breakpoint get hit (after giving it some time for copying, remote execution, attachment and symbol resolution to take place).GOING DEEPERIn the MPI Cluster Debugger project properties above, you can see many additional properties to the Run Environment. They are all optional, but you may want to understand them in order to fine tune your cluster debugging. Read all about each one of these on the MSDN page Configuration Properties for the MPI Cluster Debugger.In the Node Selector dialog above you can see more options than just the Head Node name and Number of Process to run. They should be self-explanatory but I also cover them in depth in my screencast showing you an example of why you would choose to schedule processes per core versus per node. You can also read about these options on MSDN as part of the page How to: Configure and Launch the MPI Cluster Debugger.To read through an example that touches on MPI project creation, project properties, node selector, and also usage of MPI with OpenMP plus MPI with PPL, read the MSDN page Walkthrough: Launching the MPI Cluster Debugger in Visual Studio 2010.Happy MPI debugging! Comments about this post welcome at the original blog.

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DataContractSerializer: type is not serializable because it is not public?

- by Michael B. McLaughlin

I recently ran into an odd and annoying error when working with the DataContractSerializer class for a WP7 project. I thought I’d share it to save others who might encounter it the same annoyance I had. So I had an instance of ObservableCollection<T> that I was trying to serialize (with T being a class I wrote for the project) and whenever it would hit the code to save it, it would give me: The data contract type 'ProjectName.MyMagicItemsClass' is not serializable because it is not public. Making the type public will fix this error. Alternatively, you can make it internal, and use the InternalsVisibleToAttribute attribute on your assembly in order to enable serialization of internal members - see documentation for more details. Be aware that doing so has certain security implications. This, of course, was malarkey. I was trying to write an instance of MyAwesomeClass that looked like this: [DataContract] public class MyAwesomeClass { [DataMember] public ObservableCollection<MyMagicItemsClass> GreatItems { get; set; } [DataMember] public ObservableCollection<MyMagicItemsClass> SuperbItems { get; set; } public MyAwesomeClass { GreatItems = new ObservableCollection<MyMagicItemsClass>(); SuperbItems = new ObservableCollection<MyMagicItemsClass>(); } } That’s all well and fine. And MyMagicItemsClass was also public with a parameterless public constructor. It too had DataContractAttribute applied to it and it had DataMemberAttribute applied to all the properties and fields I wanted to serialize. Everything should be cool, but it’s not because I keep getting that “not public” exception. I could tell you about all the things I tried (generating a List<T> on the fly to make sure it wasn’t ObservableCollection<T>, trying to serialize the the Collections directly, moving it all to a separate library project, etc.), but I want to keep this short. In the end, I remembered my the “Debug->Exceptions…” VS menu option that brings up the list of exception-related circumstances under which the Visual Studio debugger will break. I checked the “Thrown” checkbox for “Common Language Runtime Exceptions”, started the project under the debugger, and voilà: the true problem revealed itself. Some of my properties had fairly elaborate setters whose logic I wanted to ignore. So for some of them, I applied an IgnoreDataMember attribute to them and applied the DataMember attribute to the underlying fields instead. All of which, in line with good programming practices, were private. Well, it just so happens that WP7 apps run in a “partial trust” environment and outside of “full trust”-land, DataContractSerializer refuses to serialize or deserialize non-public members. Of course that exception was swallowed up internally by .NET so all I ever saw was that bizarre message about things that I knew for certain were public being “not public”. I changed all the private fields I was serializing to public and everything worked just fine. In hindsight it all makes perfect sense. The serializer uses reflection to build up its graph of the object in order to write it out. In partial trust, you don’t want people using reflection to get at non-public members of an object since there are potential security problems with allowing that (you could break out of the sandbox pretty quickly by reflecting and calling the appropriate methods and cause some havoc by reflecting and setting the appropriate fields in certain circumstances. The fact that you cannot reflect your own assembly seems a bit heavy-handed, but then again I’m not a compiler writer or a framework designer and I have no idea what sorts of difficulties would go into allowing that from a compilation standpoint or what sorts of security problems allowing that could present (if any). So, lesson learned. If you get an incomprehensible exception message, turn on break on all thrown exceptions and try running it again (it might take a couple of tries, depending) and see what pops out. Chances are you’ll find the buried exception that actually explains what was going on. And if you’re getting a weird exception when trying to use DataContractSerializer complaining about public types not being public, chances are you’re trying to serialize a private or protected field/property.

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RPi and Java Embedded GPIO: Sensor Reading using Java Code

- by hinkmond

And, now to program the Java code for reading the fancy-schmancy static electricity sensor connected to your Raspberry Pi, here is the source code we'll use: First, we need to initialize ourselves... /* * Java Embedded Raspberry Pi GPIO Input app */ package jerpigpioinput; import java.io.FileWriter; import java.io.RandomAccessFile; import java.text.DateFormat; import java.text.SimpleDateFormat; import java.util.Calendar; /** * * @author hinkmond */ public class JerpiGPIOInput { static final String GPIO_IN = "in"; // Add which GPIO ports to read here static String[] GpioChannels = { "7" }; /** * @param args the command line arguments */ public static void main(String[] args) { try { /*** Init GPIO port(s) for input ***/ // Open file handles to GPIO port unexport and export controls FileWriter unexportFile = new FileWriter("/sys/class/gpio/unexport"); FileWriter exportFile = new FileWriter("/sys/class/gpio/export"); for (String gpioChannel : GpioChannels) { System.out.println(gpioChannel); // Reset the port unexportFile.write(gpioChannel); unexportFile.flush(); // Set the port for use exportFile.write(gpioChannel); exportFile.flush(); // Open file handle to input/output direction control of port FileWriter directionFile = new FileWriter("/sys/class/gpio/gpio" + gpioChannel + "/direction"); // Set port for input directionFile.write(GPIO_IN); directionFile.flush(); } And, next we will open up a RandomAccessFile pointer to the GPIO port. /*** Read data from each GPIO port ***/ RandomAccessFile[] raf = new RandomAccessFile[GpioChannels.length]; int sleepPeriod = 10; final int MAXBUF = 256; byte[] inBytes = new byte[MAXBUF]; String inLine; int zeroCounter = 0; // Get current timestamp with Calendar() Calendar cal; DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss.SSS"); String dateStr; // Open RandomAccessFile handle to each GPIO port for (int channum=0; channum Then, loop forever to read in the values to the console. // Loop forever while (true) { // Get current timestamp for latest event cal = Calendar.getInstance(); dateStr = dateFormat.format(cal.getTime()); // Use RandomAccessFile handle to read in GPIO port value for (int channum=0; channum Rinse, lather, and repeat... Compile this Java code on your host PC or Mac with javac from the JDK. Copy over the JAR or class file to your Raspberry Pi, "sudo -i" to become root, then start up this Java app in a shell on your RPi. That's it! You should see a "1" value get logged each time you bring a statically charged item (like a balloon you rub on the cat) near the antenna of the sensor. There you go. You've just seen how Java Embedded technology on the Raspberry Pi is an easy way to access sensors. Hinkmond

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GoldenGate 12c - MySQL Active-Active Replication Setup

- by Jinyu Wang-Oracle

Active-active (also called Master-Master or Bi-Directional) replication captures data changes from two or more systems and replicat the changes to synchronize the data. Active-Active replication is often needed for high availability, load balancing and scaling out purposes. Oracle GoldenGate is known to be one of the first and the best replication tool handling active-active replications. As of Oracle GoldenGate 12c, it provides (Refer to Oracle GoldenGate 12.1.2 Documentation - Configuring Oracle GoldenGate for Active-Active High Availability for more information) the followings: Robust loop-back prevention Comprehensive conflict resolution and detection support Heterogeneous support across different database versions and operation systems. Oracle GoldenGate supports active-active configurations for DB2 on z/OS, LUW, and IBM i, MySQL, Oracle, SQL/MX,SQL Server, Sybase, and Teradata. However, the setup is different from database to database. In this example, I will show you how to setup an active-active data replication between two MySQL database instances. The example setup below is to have active-active replication between MySQL 5.5 and MySQL 5.6 instances and is shown as follows: MySQL 5.5 (Manager Port: 15105) Extract EXTRACT demoex01 SETENV (MYSQL_UNIX_PORT='/home/oracle/software/mysql_5.5.38/data/mysql.sock') DBOPTIONS CONNECTIONPORT 3305 DBOPTIONS HOST oraclelinux6.localdomain SOURCEDB test USERID root, PASSWORD mysql EXTTRAIL ./dirdat/extract/de TRANLOGOPTIONS ALTLOGDEST "/home/oracle/software/mysql_5.5.38/data/binlog/bin-log.index" FILTERTABLE test.checkpoint_tbl REPORTROLLOVER AT 05:30 ON saturday TABLE test.TCUSTMER; TABLE test.TCUSTORD; Pump EXTRACT demopm01 RMTHOST localhost, MGRPORT 15106, COMPRESS, TIMEOUT 30 RMTTRAIL ./dirdat/replicat/ps PASSTHRU TABLE test.TCUSTMER; TABLE test.TCUSTORD; Replicat replicat demorp01 setenv (MYSQL_UNIX_PORT='/home/oracle/software/mysql_5.5.38/data/mysql.sock') dboptions host oraclelinux6.localdomain, connectionport 3305 targetdb test, userid root, password mysql sourcedefs ./dirdat/replicat/democust.def discardfile ./dirrpt/demprp01.dsc, purge REPERROR (DEFAULT, ABEND) REPERROR(1062, IGNORE) map test.TCUSTMER, target test.TCUSTMER,colmap(usedefaults, region_code="region code"); map test.TCUSTORD, target test.TCUSTORD; MySQL 5.6 (Manager Port: 15106) Replicat replicat demorp01 setenv (MYSQL_UNIX_PORT='/home/oracle/software/mysql_5.6.19/data/mysql.sock') dboptions host oraclelinux6.localdomain, connectionport 3306 targetdb test, userid root, password mysql --assumetargetdefs sourcedefs ./dirdat/replicat/democust.def discardfile ./dirrpt/demprp01.dsc, purge map test.TCUSTMER, target test.TCUSTMER, colmap(usedefaults, "region code"=region_code); map test.TCUSTORD, target test.TCUSTORD; Extract EXTRACT demoex01 SETENV (MYSQL_UNIX_PORT='/home/oracle/software/mysql_5.6.19/data/mysql.sock') DBOPTIONS CONNECTIONPORT 3306 DBOPTIONS HOST oraclelinux6.localdomain SOURCEDB test USERID root, USERID mysql EXTTRAIL ./dirdat/extract/de TRANLOGOPTIONS ALTLOGDEST "/usr/local/mysql56/data/binlog/bin-log.index" FILTERTABLE test.checkpoint_tbl TABLE test.TCUSTMER; TABLE test.TCUSTORD; Pump EXTRACT demopm01 RMTHOST localhost, MGRPORT 15105, COMPRESS, TIMEOUT 30 RMTTRAIL ./dirdat/replicat/ps PASSTHRU TABLE test.TCUSTMER; TABLE test.TCUSTORD; The setup parameters are quite self-explanatory. The key setup is to avoid the replication data looping. Oracle GoldenGate for MySQL uses the information in the replication checkpoint table to identify the transaction applied by replicats and thus avoid extracting those transactions by Oracle GoldenGate extracts. The example setup in the extract in MySQL 5.5 instance is shown as follows. TRANLOGOPTIONS ALTLOGDEST "/home/oracle/software/mysql_5.5.38/data/binlog/bin-log.index" FILTERTABLE test.checkpoint_tbl Setting up an active-active replication is often more complicated than this and requires the following additional considerations. I would elaborate on this in the follow-up discussions.

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New R Interface to Oracle Data Mining Available for Download

- by charlie.berger

The R Interface to Oracle Data Mining ( R-ODM) allows R users to access the power of Oracle Data Mining's in-database functions using the familiar R syntax. R-ODM provides a powerful environment for prototyping data analysis and data mining methodologies. R-ODM is especially useful for: Quick prototyping of vertical or domain-based applications where the Oracle Database supports the application Scripting of "production" data mining methodologies Customizing graphics of ODM data mining results (examples: classification, regression, anomaly detection) The R-ODM interface allows R users to mine data using Oracle Data Mining from the R programming environment. It consists of a set of function wrappers written in source R language that pass data and parameters from the R environment to the Oracle RDBMS enterprise edition as standard user PL/SQL queries via an ODBC interface. The R-ODM interface code is a thin layer of logic and SQL that calls through an ODBC interface. R-ODM does not use or expose any Oracle product code as it is completely an external interface and not part of any Oracle product. R-ODM is similar to the example scripts (e.g., the PL/SQL demo code) that illustrates the use of Oracle Data Mining, for example, how to create Data Mining models, pass arguments, retrieve results etc. R-ODM is packaged as a standard R source package and is distributed freely as part of the R environment's Comprehensive R Archive Network (CRAN). For information about the R environment, R packages and CRAN, see www.r-project.org. R-ODM is particularly intended for data analysts and statisticians familiar with R but not necessarily familiar with the Oracle database environment or PL/SQL. It is a convenient environment to rapidly experiment and prototype Data Mining models and applications. Data Mining models prototyped in the R environment can easily be deployed in their final form in the database environment, just like any other standard Oracle Data Mining model. What is R? R is a system for statistical computation and graphics. It consists of a language plus a run-time environment with graphics, a debugger, access to certain system functions, and the ability to run programs stored in script files. The design of R has been heavily influenced by two existing languages: Becker, Chambers & Wilks' S and Sussman's Scheme. Whereas the resulting language is very similar in appearance to S, the underlying implementation and semantics are derived from Scheme. R was initially written by Ross Ihaka and Robert Gentleman at the Department of Statistics of the University of Auckland in Auckland, New Zealand. Since mid-1997 there has been a core group (the "R Core Team") who can modify the R source code archive. Besides this core group many R users have contributed application code as represented in the near 1,500 publicly-available packages in the CRAN archive (which has shown exponential growth since 2001; R News Volume 8/2, October 2008). Today the R community is a vibrant and growing group of dozens of thousands of users worldwide. It is free software distributed under a GNU-style copyleft, and an official part of the GNU project ("GNU S"). Resources: R website / CRAN R-ODM

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Responding to the page unload in a managed bean

- by frank.nimphius

Though ADF Faces provides an uncommitted data warning functionality, developers may have the requirement to respond to the page unload event within custom application code, programmed in a managed bean. The af:clientListener tag that is used in ADF Faces to listen for JavaScript and ADF Faces client component events does not provide the option to listen for the unload event. So this often recommended way of implementing JavaScript in ADF Faces does not work for this use case. To send an event from JavaScript to the server, ADF Faces provides the af:serverListener tag that you use to queue a CustomEvent that invokes method in a managed bean. While this is part of the solution, during testing, it turns out, the browser native JavaScript unload event itself is not very helpful to send an event to the server using the af:serverListener tag. The reason for this is that when the unload event fires, the page already has been unloaded and the ADF Faces AdfPage object needed to queue the custom event already returns null. So the solution to the unload page event handling is the unbeforeunload event, which I am not sure if all browsers support them. I tested IE and FF and obviously they do though. To register the beforeunload event, you use an advanced JavaScript programming technique that dynamically adds listeners to page events. <af:document id="d1" onunload="performUnloadEvent" clientComponent="true"> <af:resource type="javascript"> window.addEventListener('beforeunload', function (){performUnloadEvent()},false) function performUnloadEvent(){ //note that af:document must have clientComponent="true" set //for JavaScript to access the component object var eventSource = AdfPage.PAGE.findComponentByAbsoluteId('d1'); //var x and y are dummy variables obviously needed to keep the page //alive for as long it takes to send the custom event to the server var x = AdfCustomEvent.queue(eventSource, "handleOnUnload", {args:'noargs'},false); //replace args:'noargs' with key:value pairs if your event needs to //pass arguments and values to the server side managed bean. var y = 0; } </af:resource> <af:serverListener type="handleOnUnload" method="#{UnloadHandler.onUnloadHandler}"/> // rest of the page goes here … </af:document> The managed bean method called by the custom event has the following signature: public void onUnloadHandler(ClientEvent clientEvent) { } I don't really have a good explanation for why the JavaSCript variables "x" and "y" are needed, but this is how I got it working. To me it ones again shows how fragile custom JavaScript development is and why you should stay away from using it whenever possible. Note: If the unload event is produced through navigation in JavaServer Faces, then there is no need to use JavaScript for this. If you know that navigation is performed from one page to the next, then the action you want to perform can be handled in JSF directly in the context of the lifecycle.

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Wikipedia A* pathfinding algorithm takes a lot of time

- by Vee

I've successfully implemented A* pathfinding in C# but it is very slow, and I don't understand why. I even tried not sorting the openNodes list but it's still the same. The map is 80x80, and there are 10-11 nodes. I took the pseudocode from here Wikipedia And this is my implementation: public static List<PGNode> Pathfind(PGMap mMap, PGNode mStart, PGNode mEnd) { mMap.ClearNodes(); mMap.GetTile(mStart.X, mStart.Y).Value = 0; mMap.GetTile(mEnd.X, mEnd.Y).Value = 0; List<PGNode> openNodes = new List<PGNode>(); List<PGNode> closedNodes = new List<PGNode>(); List<PGNode> solutionNodes = new List<PGNode>(); mStart.G = 0; mStart.H = GetManhattanHeuristic(mStart, mEnd); solutionNodes.Add(mStart); solutionNodes.Add(mEnd); openNodes.Add(mStart); // 1) Add the starting square (or node) to the open list. while (openNodes.Count > 0) // 2) Repeat the following: { openNodes.Sort((p1, p2) => p1.F.CompareTo(p2.F)); PGNode current = openNodes[0]; // a) We refer to this as the current square.) if (current == mEnd) { while (current != null) { solutionNodes.Add(current); current = current.Parent; } return solutionNodes; } openNodes.Remove(current); closedNodes.Add(current); // b) Switch it to the closed list. List<PGNode> neighborNodes = current.GetNeighborNodes(); double cost = 0; bool isCostBetter = false; for (int i = 0; i < neighborNodes.Count; i++) { PGNode neighbor = neighborNodes[i]; cost = current.G + 10; isCostBetter = false; if (neighbor.Passable == false || closedNodes.Contains(neighbor)) continue; // If it is not walkable or if it is on the closed list, ignore it. if (openNodes.Contains(neighbor) == false) { openNodes.Add(neighbor); // If it isn’t on the open list, add it to the open list. isCostBetter = true; } else if (cost < neighbor.G) { isCostBetter = true; } if (isCostBetter) { neighbor.Parent = current; // Make the current square the parent of this square. neighbor.G = cost; neighbor.H = GetManhattanHeuristic(current, neighbor); } } } return null; } Here's the heuristic I'm using: private static double GetManhattanHeuristic(PGNode mStart, PGNode mEnd) { return Math.Abs(mStart.X - mEnd.X) + Math.Abs(mStart.Y - mEnd.Y); } What am I doing wrong? It's an entire day I keep looking at the same code.

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Ask the Readers: Would You Be Willing to Give Windows Up and Use a Different O.S.?

- by Asian Angel

When it comes to computers, Windows definitely rules the desktop in comparison to other operating systems. What we would like to know this week is if you would actually be willing to give up using Windows altogether and move to a different operating system on your computers. Note: This week’s Ask the Readers post is posing a hypothetical situation, so please refrain from starting arguments or a flame war in the comments. Good reasoned discussion is always welcome. There is no doubt that Windows is the dominant operating system in use today. Everywhere you go or look it is easy to find computers with Windows installed such as at work, home, the library, government offices, and more. For many people it is the operating system that they know and are comfortable with, which makes changing to a different operating system less appealing. Adding to the preference for Windows (or dependency based on your view) is the custom software that many businesses use on a daily basis. Throw in the high volume of people who depend on and use Microsoft Office as a standard for their business documents and it is little wonder that Windows is so dominant. So what would you use if you did decide to take a break from or permanently move away from Windows? If your choice is Linux then you have a large and wonderful variety of distributions to choose from based on what you want out of your system. Want a distribution that is easy to work with? You could choose Ubuntu, Linux Mint, or others that are engineered to be ready to go “out of the box”. Like a challenge? Perhaps Arch Linux is more your style. One of the most attractive features of all about Linux is the price…it is very hard to beat free! Maybe Mac OS X sounds like the perfect choice. It has a certain mystique and elegance associated with it and many OS X fans refuse to use anything else if given a choice. Then there is the soon to be released Chrome OS with its’ emphasis on cloud computing. This is a system that is definitely focused on being as low-maintenance and hassle-free as possible. Quick on, quick off, minimalist, and made to be portable. All of the system’s updates will occur automatically leaving you free to work and play in the cloud. But it does have its’ limitations…no installing all of those custom apps that you love using on Windows or other systems…it is literally all about the browsing window and web apps. So there you have it. If the opportunity presented itself would you, could you give Windows up and use a different operating system? Would it be easy or hard for you to do? Perhaps it would not really matter so long as you could do what you needed or wanted to do on a computer. And maybe this is the perfect time to try something new and find out…that new favorite operating system could be just an install disc away. Let us know your thoughts in the comments! How-To Geek Polls require Javascript. Please Click Here to View the Poll. Latest Features How-To Geek ETC The Complete List of iPad Tips, Tricks, and Tutorials The 50 Best Registry Hacks that Make Windows Better The How-To Geek Holiday Gift Guide (Geeky Stuff We Like) LCD? LED? Plasma? The How-To Geek Guide to HDTV Technology The How-To Geek Guide to Learning Photoshop, Part 8: Filters Improve Digital Photography by Calibrating Your Monitor The Brothers Mario – Epic Gangland Style Mario Brothers Movie Trailer [Video] Score Awesome Games on the Cheap with the Humble Indie Bundle Add a Colorful Christmas Theme to Your Windows 7 Desktop This Windows Hack Changes the Blue Screen of Death to Red Edit Images Quickly in Firefox with Pixlr Grabber Zoho Writer, Sheet, and Show Now Available in Chrome Web Store

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ArchBeat Link-o-Rama for 2012-06-29

- by Bob Rhubart

Backward-compatible vs. forward-compatible: a tale of two clouds | William Vambenepe "There is the Cloud that provides value by requiring as few changes as possible. And there is the Cloud that provides value by raising the abstraction and operation level," says William Vambenepe. "The backward-compatible Cloud versus the forward-compatible Cloud." Vambenepe was a panelist on the recent ArchBeat podcast Public, Private, and Hybrid Clouds. Andrejus Baranovskis's Blog: ADF 11g PS5 Application with Customized BPM Worklist Task Flow (MDS Seeded Customization) Oracle ACE Director Andrejus Baranovskis investigates "how you can customize a standard BPM Task Flow through MDS Seeded customization." Oracle OpenWorld 2012 Music Festival If, after a day spent in sessions at Oracle Openworld, you want nothing more than to head back to your hotel for a quiet evening spent responding to email, please ignore the rest of this message. Because every night from Sept 30 to Oct 4 the streets of San Francisco will pulsate with music from a vast array of bands representing more musical styles than a single human brain an comprehend. It's the first ever Oracle Music Festival, baby, 7:00pm to 1:00am every night. Are those emails that important...? Resource Kit: Oracle Exadata - includes demos, videos, product datasheets, and technical white papers. This free resource kit includes several customer case study videos, two 3D product demos, several product datasheets, and three technical architecture white papers. Registration is required for the who don't already have a free Oracle.com membership account. Some execs contemplate making 'Bring Your Own Device' mandatory | ZDNet "Companies and agencies are recognizing that individual employees are doing a better job of handling and managing their devices than their harried and overworked IT departments – who need to focus on bigger priorities, such as analytics and cloud," says ZDNet SOA blogger Joe McKendrick. Podcast Show Notes: Public, Private, and Hybrid Clouds All three parts of this discussion are now available. Featuring a panel of leading Oracle cloud computing experts, including Dr. James Baty, Mark T. Nelson, Ajay Srivastava, and William Vambenepe, the discussion covers an overview of the various flavors of cloud computing, the importance of standards, Why cloud computing is a paradigm shift—and why it isn't, and advice on what architects need to know to take advantage of the cloud. And for those who prefer reading to listening, a complete transcript is also available. Amazon AMIs and Oracle VM templates (Cloud Migrations) Cloud migration expert Tom Laszewski shares an objective comparison of these two resources. IOUC : Blogs : Read the latest news on the global user group community - June 2012! The June 2012 edition of "Are You a Member Yet?"—the quarterly newsletter about Oracle user group communities around the world. Webcast: Introducing Identity Management 11g R2 - July 19 Date: Thursday, July 19, 2012 Time: 10am PT / 1pm ET Please join Oracle and customer executives for the launch of Oracle Identity Management 11g R2, the breakthrough technology that dramatically expands the reach of identity management to cloud and mobile environments. Thought for the Day "The most important single aspect of software development is to be clear about what you are trying to build." — Bjarne Stroustrup Source: SoftwareQuotes.com

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WebLogic Server Performance and Tuning: Part II - Thread Management

- by Gokhan Gungor

WebLogic Server, like any other java application server, provides resources so that your applications use them to provide services. Unfortunately none of these resources are unlimited and they must be managed carefully. One of these resources is threads which are pooled to provide better throughput and performance along with the fast response time and to avoid deadlocks. Threads are execution points that WebLogic Server delivers its power and execute work. Managing threads is very important because it may affect the overall performance of the entire system. In previous releases of WebLogic Server 9.0 we had multiple execute queues and user defined thread pools. There were different queues for different type of work which had fixed number of execute threads. Tuning of this thread pools and finding the proper number of threads was time consuming which required many trials. WebLogic Server 9.0 and the following releases use a single thread pool and a single priority-based execute queue. All type of work is executed in this single thread pool. Its size (thread count) is automatically decreased or increased (self-tuned). The new “self-tuning” system simplifies getting the proper number of threads and utilizing them.Work manager allows your applications to run concurrently in multiple threads. Work manager is a mechanism that allows you to manage and utilize threads and create rules/guidelines to follow when assigning requests to threads. We can set a scheduling guideline or priority a request with a work manager and then associate this work manager with one or more applications. At run-time, WebLogic Server uses these guidelines to assign pending work/requests to execution threads. The position of a request in the execute queue is determined by its priority. There is a default work manager that is provided. The default work manager should be sufficient for most applications. However there can be cases you want to change this default configuration. Your application(s) may be providing services that need mixture of fast response time and long running processes like batch updates. However wrong configuration of work managers can lead a performance penalty while expecting improvement.We can define/configure work managers at;• Domain Level: config.xml• Application Level: weblogic-application.xml • Component Level: weblogic-ejb-jar.xml or weblogic.xml(For a specific web application use weblogic.xml)We can use the following predefined rules/constraints to manage the work;• Fair Share Request Class: Specifies the average thread-use time required to process requests. The default is 50.• Response Time Request Class: Specifies a response time goal in milliseconds.• Context Request Class: Assigns request classes to requests based on context information.• Min Threads Constraint: Limits the number of concurrent threads executing requests.• Max Threads Constraint: Guarantees the number of threads the server will allocate to requests.• Capacity Constraint: Causes the server to reject requests only when it has reached its capacity. Let’s create a work manager for our application for a long running work.Go to WebLogic console and select Environment | Work Managers from the domain structure tree. Click New button and select Work manager and click next. Enter the name for the work manager and click next. Then select the managed server instances(s) or clusters from available targets (the one that your long running application is deployed) and finish. Click on MyWorkManager, and open the Configuration tab and check Ignore Stuck Threads and save. This will prevent WebLogic to tread long running processes (that is taking more than a specified time) as stuck and enable to finish the process.

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11.10 desktop alerts (volume change and terminal bell) stopped working but all other audio still works

- by FlabbergastedPickle

All, My sound works just fine in 11.10 64-bit install on HP dm1-4050 Sandy Bridge notebook (e.g. audio works in Banshee, flash, games, browser, Thunderbird email notification, etc.), but the core desktop notifications (e.g. pressing a tab in a terminal where there is more than one option should trigger a terminal bell, or changing volume using volume keys should be accompanied with the supporting "quack" that the volume app makes) do not work. I've intentionally disabled login sound as explained here on ask ubuntu but even enabling it back makes no difference. These notifications did work before just fine and I am not sure when did the actually stop working but it must've been fairly recently. Only things I did were trying to install some ppa edge xorg drivers for my intel card (a separate issue) but also reverted them all with ppa-purge once I discovered they did not improve anything. Other thing I did was check volume settings with alsamixer and did alsactl store for the soundcard after I did some experimenting with volume settings for PCM (on my laptop PCM at 100% crackles so I had to lower it and make pulseaudio ignore its setting as per ask ubuntu's page). That said, neither of these should have any bearing on the said notifications since the volume is up and they clearly work everywhere else but the core desktop events. The system ready drum sound when Ubuntu boots and user reaches the login screen also does not work. The guest login behaves exactly same as mine. Audio works (including the login sound since I've not disabled it for the guest account), but no quacks when changing the volume or terminal bell sounds... I've tried copying ubuntu sounds to /usr/share/sounds/ as suggested on ask ubuntu and that did not work. I also tried using dconf-editor to check sound theme settings and tried both freedesktop (which is what it was set to) and ubuntu, as suggested on ask ubuntu. This did not work either. I tried purging the ~/.pulse folder and the /tmp/*pulse* entries, rebooting and restarting pulseaudio with -D flag. While audio came back on and behaved just fine in all aspects (e.g. one can adjust volume levels, play music, games, in-browser sound stuff, and other app alerts) except for the system ready drum sound (at the login screen), and any system event (terminal bell and volume change quack sound). It is interesting that the quack sound works inside system settings-sound when adjusting levels there, but it does not when volume is changed via top bar's volume settings... I do recall that at one point yesterday when I was restarting pulseaudio the quacks that accompany volume change did start working but I have no idea what caused that. This was also when I first realized those alerts were not working. After rebooting it was again gone. I did compile my own 3.0.14-rt31 kernel a little while ago as instructed on one of the wiki's for the 11.10 rt kernel. Everything works as before except for the said sound alerts. I am not sure if this began happening since I started using the rt kernel though and yesterday's momentary ability to hear those quacks while changing the volume make me believe that the kernel is not one responsible for this problem. One more thing I can think of is that I used alsoft-conf tool to configure buffering on the OpenAL (due to TA Spring's choppy audio) and changed in there default audio device to ALSA. I also tried reverting it to Pulseaudio as the only allowed output but the bottom part of the Backend tab always reverts to ALSA even when I select Pulseaudio. The pulseaudio does remain as the only active choice on top. This, however, once again does not make any sense in terms of preventing desktop audio alerts when everything else including OpenAL games plays sound just fine... So, there you have it, as verbose as I could make it :-). I tried all I could find on this issue and had no luck so far... Any ideas?

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Open a File Browser From Your Current Command Prompt/Terminal Directory

- by The Geek

Ever been doing some work at the command line when you realized… it would be a lot easier if I could just use the mouse for this task? One command later, you’ll have a window open to the same place that you’re at. This same tip works in more than one operating system, so we’ll detail how to do it in every way we know how. Open a File Browser in Windows We’ve actually covered this before when we told you how to open an Explorer window from the command prompt’s current directory, but we’ll briefly review: Just type the follow command into your command prompt: explorer . Note: You could actually just type “start .” instead. And you’ll then see a file browsing window set to the same directory you were previous at. And yes, this screenshot is from Vista, but it works the same in every version of Windows. If that wasn’t good enough, you should really read how you can navigate in the File Open/Save dialogs with just the keyboard—now that’s a Stupid Geek Trick! Open a File Browser in Linux For this exercise, we’re going to assume that you’re using Gnome under a Linux flavor like Ubuntu, because that’s the most common. From your terminal window, just type in the following command: nautilus . And the next thing you know, you’ll have a file browser window open at the current location. You’ll see some type of error message at the prompt, but you can pretty much ignore that. You can also use “gnome-open .” if you want. Open Finder in Mac OS X All the Mac computers in this office are running Linux, so we haven’t had a chance to verify, but you should be able to use the following command on OS X to open Finder in the current terminal location: open . Open Dolphin on Linux KDE4 dolphin . Got any extra tips to help out your fellow readers? How do you do the same thing in KDE3? What about OS X? Leave your savvy advice in the comments, and maybe we’ll update the article. Or not. Either way, it’ll help somebody! Similar Articles Productive Geek Tips Keyboard Ninja: Concatenate Multiple Text Files in WindowsStupid Geek Tricks: Open an Explorer Window from the Command Prompt’s Current DirectoryHow to automate FTP uploads from the Windows Command LineShell Geek: Rename Multiple Files At OnceAdd "Open with gedit" to the right click menu in Ubuntu TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 Home Networks – How do they look like & the problems they cause Check Your IMAP Mail Offline In Thunderbird Follow Finder Finds You Twitter Users To Follow Combine MP3 Files Easily QuicklyCode Provides Cheatsheets & Other Programming Stuff Download Free MP3s from Amazon

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A proposal for #DAX Code Formatting #ssas #powerpivot #tabular

- by Marco Russo (SQLBI)

I recently published a set of rules for DAX code formatting. The following is an example of what I obtain: CALCULATE ( SUMX ( Orders, Orders[Amount] ), FILTER ( ALL ( Customers ), CALCULATE ( COUNTROWS ( Sales ), ALL ( Calendar[Date] ) ) > 42 + 8 – 25 * ( 3 - 1 ) + 2 – 1 + 2 – 1 + CALCULATE ( 2 + 2 – 2 + 2 - 2 ) – CALCULATE ( 4 ) ) ) The goal is to improve code readability and I look forward to implement a code formatting feature in DAX Studio. The DAX Editor already supports the rules described in the article. I am also considering whether to add a rule specific for ADDCOLUMNS / SUMMARIZE because I would like to see the “pairs” of arguments to define a column in the same row or with a special indentation rule (DAX expression for a column is indented in the line following the column name). EVALUATE CALCULATETABLE ( CALCULATETABLE ( SUMMARIZE ( Audience, 'Date'[Year], Individuals[Gender], Individuals[AgeRange], "Num of Rows", FORMAT (COUNTROWS (Audience), "#,#"), "Weighted Mean Age", SUMX (Audience, Audience[Weight] * Audience[Age]) / SUM (Audience[Weight]) ), SUMMARIZE ( BridgeIndividualsTargets, Individuals[ID_Individual] ), Audience[Weight] > 0 ), Targets[Target] = "Maschi", 'Date'[Year] = 2010, 'Date'[MonthName] = "January" ) I would like to get feedback for that – you can use comments here or comments in original article. Thanks!

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What are the disadvantages of self-encapsulation?

- by Dave Jarvis

Background Tony Hoare's billion dollar mistake was the invention of null. Subsequently, a lot of code has become riddled with null pointer exceptions (segfaults) when software developers try to use (dereference) uninitialized variables. In 1989, Wirfs-Brock and Wikerson wrote: Direct references to variables severely limit the ability of programmers to re?ne existing classes. The programming conventions described here structure the use of variables to promote reusable designs. We encourage users of all object-oriented languages to follow these conventions. Additionally, we strongly urge designers of object-oriented languages to consider the effects of unrestricted variable references on reusability. Problem A lot of software, especially in Java, but likely in C# and C++, often uses the following pattern: public class SomeClass { private String someAttribute; public SomeClass() { this.someAttribute = "Some Value"; } public void someMethod() { if( this.someAttribute.equals( "Some Value" ) ) { // do something... } } public void setAttribute( String s ) { this.someAttribute = s; } public String getAttribute() { return this.someAttribute; } } Sometimes a band-aid solution is used by checking for null throughout the code base: public void someMethod() { assert this.someAttribute != null; if( this.someAttribute.equals( "Some Value" ) ) { // do something... } } public void anotherMethod() { assert this.someAttribute != null; if( this.someAttribute.equals( "Some Default Value" ) ) { // do something... } } The band-aid does not always avoid the null pointer problem: a race condition exists. The race condition is mitigated using: public void anotherMethod() { String someAttribute = this.someAttribute; assert someAttribute != null; if( someAttribute.equals( "Some Default Value" ) ) { // do something... } } Yet that requires two statements (assignment to local copy and check for null) every time a class-scoped variable is used to ensure it is valid. Self-Encapsulation Ken Auer's Reusability Through Self-Encapsulation (Pattern Languages of Program Design, Addison Wesley, New York, pp. 505-516, 1994) advocated self-encapsulation combined with lazy initialization. The result, in Java, would resemble: public class SomeClass { private String someAttribute; public SomeClass() { setAttribute( "Some Value" ); } public void someMethod() { if( getAttribute().equals( "Some Value" ) ) { // do something... } } public void setAttribute( String s ) { this.someAttribute = s; } public String getAttribute() { String someAttribute = this.someAttribute; if( someAttribute == null ) { setAttribute( createDefaultValue() ); } return someAttribute; } protected String createDefaultValue() { return "Some Default Value"; } } All duplicate checks for null are superfluous: getAttribute() ensures the value is never null at a single location within the containing class. Efficiency arguments should be fairly moot -- modern compilers and virtual machines can inline the code when possible. As long as variables are never referenced directly, this also allows for proper application of the Open-Closed Principle. Question What are the disadvantages of self-encapsulation, if any? (Ideally, I would like to see references to studies that contrast the robustness of similarly complex systems that use and don't use self-encapsulation, as this strikes me as a fairly straightforward testable hypothesis.)

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