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• 2D Animation Smoothness - Delta time vs. Kinematics

  - by viperld002

  I'm animating a sprite in 2D with key frames of rotation and xy-positions. I've recently had a discussion with someone saying that when the device (happens to be an iPad using cocos2D) hits a performance bump due to whatever else the user may be doing, lag will arise and that the best way to fight it is to not use actual positions, but velocities, accelerations and torques with kinematics. His message is to evaluate the positions and rotations from these speeds at the current point in time. I've never experienced a situation where I've heard of using kinematics to stem lag in 2D animations and am not sure of how effective it could be. Also, it seems to be overkill. The application is not networked so it's all running on a local device. The desired effect is that the animation always plays as closely as it can to the target frame rate. Wouldn't the technique suffer the same problems as just using the time since the last frame or a fixed time step since the kinematics would also require some time value to perform the calculation? What techniques could you suggest to best achieve the desired effect? EDIT 1 Thank you for your responses, they are very illuminating. I want to clarify my question before choosing an answer however, to make sure that this post really serves it's purpose. I have a sprite of a ball, and a text file with 3 arrays worth of information (rotation,translations x, translations y) with each unit of information existing as a key frame to be stepped through (0 to 49 and back to 0 to replay it again). I have this playing by interpolating from the current key frame to the next, every n-units of time. The animation is visibly correct when compared to a video I was given of it, and it is smooth because of the interpolations between the key frames. This is the existing state of the project. There are no physics simulated, only a static animation of a ball moving in a way an artist specifically designed. Should I, instead of rotation in degrees and translations by positions in space, derive velocities, accelerations and torques to express this static animation as a function of time? As in, position now = foo(time now), where foo uses kinematics.

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• Is the expected time shown during file copy the best time or worst time?

  - by chinmoy

  When we copy files in windows, we get an expected time of completion. Is that time the best time or the worst time? Also are you assuming the environmental variables?

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• MySQL: should I use "date" and "time" fields when I already have a timestamp field?

  - by KeyStroke

  Hi, I have a MySQL table where there is a 'date_added' (date) field, 'time_added' (time) field and 'timestamp' (int) field. I found out afterwards that I can convert timestamp to a date or a time anyway, so so does that mean I could get rid of the other date/time fields and keep the timestamp only? Thanks in advance

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• How to change the date/time in Python for all modules?

  - by Felix Schwarz

  When I write with business logic, my code often depends on the current time. For example the algorithm which looks at each unfinished order and checks if an invoice should be sent (which depends on the no of days since the job was ended). In these cases creating an invoice is not triggered by an explicit user action but by a background job. Now this creates a problem for me when it comes to testing: I can test invoice creation itself easily However it is hard to create an order in a test and check that the background job identifies the correct orders at the correct time. So far I found two solutions: In the test setup, calculate the job dates relative to the current date. Downside: The code becomes quite complicated as there are no explicit dates written anymore. Sometimes the business logic is pretty complex for edge cases so it becomes hard to debug due to all these relative dates. I have my own date/time accessor functions which I use throughout my code. In the test I just set a current date and all modules get this date. So I can simulate an order creation in February and check that the invoice is created in April easily. Downside: 3rd party modules do not use this mechanism so it's really hard to integrate+test these. The second approach was way more successful to me after all. Therefore I'm looking for a way to set the time Python's datetime+time modules return. Setting the date is usually enough, I don't need to set the current hour or second (even though this would be nice). Is there such a utility? Is there an (internal) Python API that I can use?

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• How can you set a time limit for a PowerShell script to run for?

  - by calrain

  I want to set a time limit on a PowerShell (v2) script so it forcibly exits after that time limit has expired. I see in PHP they have commands like set_time_limit and max_execution_time where you can limit how long the script and even a function can execute for. With my script, a do/while loop that is looking at the time isn't appropriate as I am calling an external code library that can just hang for a long time. I want to limit a block of code and only allow it to run for x seconds, after which I will terminate that code block and return a response to the user that the script timed out. I have looked at background jobs but they operate in a different thread so won't have kill rights over the parent thread. Has anyone dealt with this or have a solution? Thanks!

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• Series On Embedded Development (Part 2) - Build-Time Optionality

  - by user12612705

  In this entry on embedded development, I'm going to discuss build-time optionality (BTO). BTO is the ability to subset your software at build-time so you only use what is needed. BTO typically pertains more to software providers rather then developers of final products. For example, software providers ship source products, frameworks or platforms which are used by developers to build other products. If you provide a source product, you probably don't have to do anything to support BTO as the developers using your source will only use the source they need to build their product. If you provide a framework, then there are some things you can do to support BTO. Say you provide a Java framework which supports audio and video. If you provide this framework in a single JAR, then developers who only want audio are forced to ship their product with the video portion of your framework even though they aren't using it. In this case, support providing the framework in separate JARs...break the framework into an audio JAR and a video JAR and let the users of your framework decide which JARs to include in their product. Sometimes this is as simple as packaging, but if, for example, the video functionality is dependent on the audio functionality, it may require coding work to cleanly separate the two. BTO can also work at install-time, and this is sometimes overlooked. Let's say your building a phone application which can use Near Field Communications (NFC) if it's available on the phone, but it doesn't require NFC to work. Typically you'd write one app for all phones (saving you time)...both those that have NFC and those that don't, and just use NFC if it's there. However, for better efficiency, you can detect at install-time if the phone supports NFC and not install the NFC portion of your app if the phone doesn't support NFC. This requires that you write the app so it can run without the optional NFC code and that you write your install app so it can detect NFC and do the right thing at install-time. Supporting install-time optionality will save persistent footprint on the phone, something your customers will appreciate, your app "neighbors" will appreciate, and that you'll appreciate when they save static footprint for you. In the next article, I'll talk about runtime optionality.

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• How do I build (get/download) time.h library?

  - by coffeenet

  I am trying to build a project on Linux via Makefile. I keep getting cannot find <sys/time.h> error. I asked around, and I was told that my project doesn't have access to library folders. Therefore, I am trying to solve this problem by using the time library locally inside my project's folder. I am very new to Linux. So, please forgive my question if it sounds naive. I found this, but I don't know what files I need, and how to build the library. http://sourceware.org/git/?p=glibc.git;a=tree;f=time;h=c950c5d4dd90541e8f3c7e1649fcde4aead989bb;hb=master Where can I find the time.h library/package? How do I build the library?

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• Getting current time in milliseconds

  - by user90293423

  How to get the current time in milliseconds? I'm working on a hacking simulation game and when ever someone connects to another computer/NPC, a login screen popups with a button on the side called BruteForce. When BruteForce is clicked, what i want the program to do is, calculate how many seconds cracking the password is going to take based on the player's CPU speed but that's the easy part. The hard part is i want to enter a character in the password's box every X milliseconds based on a TimeToCrack divided by PasswordLength formula. But since i don't know how to find how many milliseconds have elapsed since the second has passed, the program waits until the CurrentTime is higher than the TimeBeforeTheLoopStarted + HowLongItTakesToTypeaCharacter which is always going to be a second. How would you handle my problems? I've commented the game breaking part. std::vector<QString> hardware = user.getHardware(); QString CPU = hardware[0]; unsigned short Speed = 0; if(CPU == "OMG SingleCore 1.8GHZ"){ Speed = 2; } const short passwordLength = password.length(); /* It's equal to 16 */ int Time = passwordLength / Speed; double TypeSpeed = Time / passwordLength; time_t t = time(0); struct tm * now = localtime(&t); unsigned short EndTime = (now->tm_sec + Time) % 60; unsigned short CurrentTime = 0; short i = passwordLength - 1; do{ t = time(0); now = localtime(&t); CurrentTime = now->tm_sec; do{ t = time(0); now = localtime(&t); }while(now->tm_sec < CurrentTime + TypeSpeed); /* Highly flawed */ /* Do this while your integer value is under this double value */ QString tempPass = password; tempPass.chop(i); ui->lineEdit_2->setText(tempPass); i--; }while(CurrentTime != EndTime);

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• Most efficient way to implement delta time

  - by Starkers

  Here's one way to implement delta time: /// init /// var duration = 5000, currentTime = Date.now(); // and create cube, scene, camera ect ////// function animate() { /// determine delta /// var now = Date.now(), deltat = now - currentTime, currentTime = now, scalar = deltat / duration, angle = (Math.PI * 2) * scalar; ////// /// animate /// cube.rotation.y += angle; ////// /// update /// requestAnimationFrame(render); ////// } Could someone confirm I know how it works? Here what I think is going on: Firstly, we set duration at 5000, which how long the loop will take to complete in an ideal world. With a computer that is slow/busy, let's say the animation loop takes twice as long as it should, so 10000: When this happens, the scalar is set to 2.0: scalar = deltat / duration scalar = 10000 / 5000 scalar = 2.0 We now times all animation by twice as much: angle = (Math.PI * 2) * scalar; angle = (Math.PI * 2) * 2.0; angle = (Math.PI * 4) // which is 2 rotations When we do this, the cube rotation will appear to 'jump', but this is good because the animation remains real-time. With a computer that is going too quickly, let's say the animation loop takes half as long as it should, so 2500: When this happens, the scalar is set to 0.5: scalar = deltat / duration scalar = 2500 / 5000 scalar = 0.5 We now times all animation by a half: angle = (Math.PI * 2) * scalar; angle = (Math.PI * 2) * 0.5; angle = (Math.PI * 1) // which is half a rotation When we do this, the cube won't jump at all, and the animation remains real time, and doesn't speed up. However, would I be right in thinking this doesn't alter how hard the computer is working? I mean it still goes through the loop as fast as it can, and it still has render the whole scene, just with different smaller angles! So this a bad way to implement delta time, right? Now let's pretend the computer is taking exactly as long as it should, so 5000: When this happens, the scalar is set to 1.0: angle = (Math.PI * 2) * scalar; angle = (Math.PI * 2) * 1; angle = (Math.PI * 2) // which is 1 rotation When we do this, everything is timsed by 1, so nothing is changed. We'd get the same result if we weren't using delta time at all! My questions are as follows Mostly importantly, have I got the right end of the stick here? How do we know to set the duration to 5000 ? Or can it be any number? I'm a bit vague about the "computer going too quickly". Is there a way loop less often rather than reduce the animation steps? Seems like a better idea. Using this method, do all of our animations need to be timesed by the scalar? Do we have to hunt down every last one and times it? Is this the best way to implement delta time? I think not, due to the fact the computer can go nuts and all we do is divide each animation step and because we need to hunt down every step and times it by the scalar. Not a very nice DSL, as it were. So what is the best way to implement delta time? Below is one way that I do not really get but may be a better way to implement delta time. Could someone explain please? // Globals INV_MAX_FPS = 1 / 60; frameDelta = 0; clock = new THREE.Clock(); // In the animation loop (the requestAnimationFrame callback)… frameDelta += clock.getDelta(); // API: "Get the seconds passed since the last call to this method." while (frameDelta >= INV_MAX_FPS) { update(INV_MAX_FPS); // calculate physics frameDelta -= INV_MAX_FPS; } How I think this works: Firstly we set INV_MAX_FPS to 0.01666666666 How we will use this number number does not jump out at me. We then intialize a frameDelta which stores how long the last loop took to run. Come the first loop frameDelta is not greater than INV_MAX_FPS so the loop is not run (0 = 0.01666666666). So nothing happens. Now I really don't know what would cause this to happen, but let's pretend that the loop we just went through took 2 seconds to complete: We set frameDelta to 2: frameDelta += clock.getDelta(); frameDelta += 2.00 Now we run an animation thanks to update(0.01666666666). Again what is relevance of 0.01666666666?? And then we take away 0.01666666666 from the frameDelta: frameDelta -= INV_MAX_FPS; frameDelta = frameDelta - INV_MAX_FPS; frameDelta = 2 - 0.01666666666 frameDelta = 1.98333333334 So let's go into the second loop. Let's say it took 2(? Why not 2? Or 12? I am a bit confused): frameDelta += clock.getDelta(); frameDelta = frameDelta + clock.getDelta(); frameDelta = 1.98333333334 + 2 frameDelta = 3.98333333334 This time we enter the while loop because 3.98333333334 = 0.01666666666 We run update We take away 0.01666666666 from frameDelta again: frameDelta -= INV_MAX_FPS; frameDelta = frameDelta - INV_MAX_FPS; frameDelta = 3.98333333334 - 0.01666666666 frameDelta = 3.96666666668 Now let's pretend the loop is super quick and runs in just 0.1 seconds and continues to do this. (Because the computer isn't busy any more). Basically, the update function will be run, and every loop we take away 0.01666666666 from the frameDelta untill the frameDelta is less than 0.01666666666. And then nothing happens until the computer runs slowly again? Could someone shed some light please? Does the update() update the scalar or something like that and we still have to times everything by the scalar like in the first example?

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• Design pattern for an automated mechanical test bench

  - by JJS

  Background I have a test fixture with a number of communication/data acquisition devices on it that is used as an end of line test for a product. Because of all the various sensors used in the bench and the need to run the test procedure in near real-time, I'm having a hard time structuring the program to be more friendly to modify later on. For example, a National Instruments USB data acquisition device is used to control an analog output (load) and monitor an analog input (current), a digital scale with a serial data interface measures position, an air pressure gauge with a different serial data interface, and the product is interfaced through a proprietary DLL that handles its own serial communication. The hard part The "real-time" aspect of the program is my biggest tripping point. For example, I need to time how long the product needs to go from position 0 to position 10,000 to the tenth of a second. While it's traveling, I need to ramp up an output of the NI DAQ when it reaches position 6,000 and ramp it down when it reaches position 8,000. This sort of control looks easy from browsing NI's LabVIEW docs but I'm stuck with C# for now. All external communication is done by polling which makes for lots of annoying loops. I've slapped together a loose Producer Consumer model where the Producer thread loops through reading the sensors and sets the outputs. The Consumer thread executes functions containing timed loops that poll the Producer for current data and execute movement commands as required. The UI thread polls both threads for updating some gauges indicating current test progress. Unsure where to start Is there a more appropriate pattern for this type of application? Are there any good resources for writing control loops in software (non-LabVIEW) that interface with external sensors and whatnot?

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• Make the Time

  - by WonderOfItAll

  Took the little one to the pool tonight for swim lessons. Okay, Okay. They're not really lessons so much as they are "Hey, here's a few bucks, let me rent out a small section of your pool to swim around with my little one" Saw a dad at the pool. Bluetooth on, iPad in hand, and two year old somewhere around there. Saw a mom at the pool. Arguing with her five year old to NOT take a shower after swimming. Bluetooth on, iPad in hand, work laptop open on stadium seats. Her reasoning for not wanting the child to shower "Look, I have to get this stuff to the office by 6:30, we don't have time for you to shower. Let's go" Wait, isn't the whole point of this little experience called Mommy and Me (or, as in my case, Daddy and Me). Wherein Mommy/Daddy is supposed to spend time with little one. Not with the Bluetooth. Not with the work laptop. Dad (yeah, the same dad from earlier), in the pool. Bluetooth off (it's not waterproof or I'm sure he would've had it on), two year old in hand and iPad somewhere put away. Getting frustrated with kid because he won't 'perform' on command. Here's a little exchange Kid: "I don't wanna get in the water" Dad: "Well, we're here for 30 minutes, get in the water" Kid: "No, don't wanna" Dad: "Fine, I'm getting in" and, true to his word, in he goes, off to swim. Kid: Crying Dad: "Well, c'mon" Kid: Walking to stands Dad: Ignoring kid Kid: At stands Dad: Out of pool, drying off. Frustrated. Grabs bag, grabs kid, leaves How sad. It really seems like I am living in a generation of parents who view their children as one big scheduled distraction to another. It's almost like the dad was saying "Look, little 2 year old boy, I have a busy scheduled. Right now my Outlook Calendar tells me that I have 30 mins to spend with you, so, let's go kid: PERFORM because I have the time" Really? Can someone please tell me when the hell this happened? When did spending time with your kid, spending time with your family, spending time with your spouse, etc... become a distraction? I've seen people at work all day Tweeting throughout the day, checked in with Four Square, IM up and running constantly so they can 'stay in touch' only to see these same folks come home and be irritated because their kids or their spouse wants to connect with the. I've seen these very same people leave the house, go to the corner bar/store/you-name-the-place to be 'alone' only to find them there, plugged in, tweeting away, etc, etc, etc I LOVE technology. I love working with technology. But I also know that I am a human being. A person who, by very definition, is a social being. I needed social interactions and contact--and, no, I'm not talking about the Social Graph kind of connections, I'm talking about those interactions which, *GASP* involve eye to eye contact and human contact. A recent study found that the number one complaint of kids is that they feel they have to compete with technology for their parents time and attention. The number one wish from high school kids? That there parents would turn off the computer/tv/cell phone at dinner. This, coming from high school kids. Shouldn't that tell you a whole helluva lot? So, do yourself a favor tomorrow. Plug into technology all day. Throw yourself into it. Be passionate about what you do. When you walk through the door to your family, turn it all off for 30 mins and be there with your loved ones. If you can manage to play Angry Birds, I'm sure you can handle being disconnected for 30 minutes. Make the time

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• How to compare two times in milliseconds precision?

  - by Marcos Issler

  I have a subtitle text file that works with standart srt format 00:00:00,000 Hour, minutes, seconds, milliseconds. I want to create a timer to update the subtitle screen and check the current time to know what subtitle show on screen. Which is the best to use? NSTimeInterval, NSDate? I think the best is to convert all to times to milliseconds number and compare. But NSTimeInterval works with seconds, not milliseconds. Some clue? Marcos

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• Super Mario – 3D Chalk Art (Time Lapse) [Video]

  - by Asian Angel

  This awesome time-lapse video lets you watch artist Chris Carlson create a fantastic 3D chalk art rendition of Mario on a sidewalk setting. There is certainly a lot more work and precision to it than some people may believe… Super Mario – 3D Chalk Art (Time Lapse) [via Neatorama] How to Banish Duplicate Photos with VisiPic How to Make Your Laptop Choose a Wired Connection Instead of Wireless HTG Explains: What Is Two-Factor Authentication and Should I Be Using It?

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• NTP daemon or ntpdate doesn't synchronize

  - by user2862333

  I'm having some problems with synchronization with an NTP server. 1) The NTP daemon doesn't sync the system clock at all, even though it's running (confirmed with /etc/init.d/ntp status). Forcing to sync with ntpd -q or ntpd -gq does not work either. 2) Stopping the NTP daemon and syncing manually with ntpdate does give me the following output: ~# ntpdate -d 0.debian.pool.ntp.org 6 Nov 16:48:53 ntpdate[4417]: ntpdate [email protected] Sat May 12 09:07:19 UTC 2012 (1) transmit(79.132.237.5) receive(79.132.237.5) transmit(85.234.197.2) receive(85.234.197.2) transmit(194.50.97.34) receive(194.50.97.34) transmit(79.132.237.1) receive(79.132.237.1) transmit(79.132.237.5) receive(79.132.237.5) transmit(85.234.197.2) receive(85.234.197.2) transmit(194.50.97.34) receive(194.50.97.34) transmit(79.132.237.1) receive(79.132.237.1) transmit(79.132.237.5) receive(79.132.237.5) transmit(85.234.197.2) receive(85.234.197.2) transmit(194.50.97.34) receive(194.50.97.34) transmit(79.132.237.1) receive(79.132.237.1) transmit(79.132.237.5) receive(79.132.237.5) transmit(85.234.197.2) receive(85.234.197.2) transmit(194.50.97.34) receive(194.50.97.34) transmit(79.132.237.1) receive(79.132.237.1) server 79.132.237.5, port 123 stratum 2, precision -20, leap 00, trust 000 refid [79.132.237.5], delay 0.05141, dispersion 0.00145 transmitted 4, in filter 4 reference time: d624e3b1.f490b90d Wed, Nov 6 2013 16:50:09.955 originate timestamp: d624e457.eaaf787c Wed, Nov 6 2013 16:52:55.916 transmit timestamp: d624e36c.4a7036fd Wed, Nov 6 2013 16:49:00.290 filter delay: 0.08537 0.05141 0.05151 0.06346 0.00000 0.00000 0.00000 0.00000 filter offset: 235.6038 235.6087 235.6095 235.6068 0.000000 0.000000 0.000000 0.000000 delay 0.05141, dispersion 0.00145 offset 235.608782 server 85.234.197.2, port 123 stratum 2, precision -20, leap 00, trust 000 refid [85.234.197.2], delay 0.05151, dispersion 0.00336 transmitted 4, in filter 4 reference time: d624e3e7.dc6cd02b Wed, Nov 6 2013 16:51:03.861 originate timestamp: d624e458.1c91031f Wed, Nov 6 2013 16:52:56.111 transmit timestamp: d624e36c.7da1d882 Wed, Nov 6 2013 16:49:00.490 filter delay: 0.05765 0.07750 0.06013 0.05151 0.00000 0.00000 0.00000 0.00000 filter offset: 235.6048 235.6014 235.6035 235.6078 0.000000 0.000000 0.000000 0.000000 delay 0.05151, dispersion 0.00336 offset 235.607826 server 194.50.97.34, port 123 stratum 3, precision -23, leap 00, trust 000 refid [194.50.97.34], delay 0.03021, dispersion 0.00090 transmitted 4, in filter 4 reference time: d624e38d.2bce952c Wed, Nov 6 2013 16:49:33.171 originate timestamp: d624e458.4dbbc114 Wed, Nov 6 2013 16:52:56.303 transmit timestamp: d624e36c.b0d38834 Wed, Nov 6 2013 16:49:00.690 filter delay: 0.03030 0.03636 0.03091 0.03021 0.00000 0.00000 0.00000 0.00000 filter offset: 235.6095 235.6085 235.6098 235.6105 0.000000 0.000000 0.000000 0.000000 delay 0.03021, dispersion 0.00090 offset 235.610589 server 79.132.237.1, port 123 stratum 3, precision -20, leap 00, trust 000 refid [79.132.237.1], delay 0.05113, dispersion 0.00305 transmitted 4, in filter 4 reference time: d624dfcb.6acea332 Wed, Nov 6 2013 16:33:31.417 originate timestamp: d624e458.838672ad Wed, Nov 6 2013 16:52:56.513 transmit timestamp: d624e36c.e405181c Wed, Nov 6 2013 16:49:00.890 filter delay: 0.06345 0.05113 0.05681 0.05656 0.00000 0.00000 0.00000 0.00000 filter offset: 235.6087 235.6038 235.6010 235.6074 0.000000 0.000000 0.000000 0.000000 delay 0.05113, dispersion 0.00305 offset 235.603888 6 Nov 16:49:00 ntpdate[4417]: step time server 79.132.237.5 offset 235.608782 sec Clearly, ntpdate can reach the NTP server(s), but after checking the clock, it hasn't changed and is still displaying the wrong time. Any ideas what would be the problem would be much appreciated.

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• Issuing Current Time Increments in StreamInsight (A Practical Example)

  The issuing of a Current Time Increment, Cti, in StreamInsight is very definitely one of the most important concepts to learn if you want your Streams to be responsive. A full discussion of how to issue Ctis is beyond the scope of this article but a very good explanation in addition to Books Online can be found in these three articles by a member of the StreamInsight team at Microsoft, Ciprian Gerea. Time in StreamInsight Series http://blogs.msdn.com/b/streaminsight/archive/2010/07/23/time-in-streaminsight-i.aspx http://blogs.msdn.com/b/streaminsight/archive/2010/07/30/time-in-streaminsight-ii.aspx http://blogs.msdn.com/b/streaminsight/archive/2010/08/03/time-in-streaminsight-iii.aspx A lot of the problems I see with unresponsive or stuck streams on the MSDN Forums are to do with how Ctis are enqueued or in a lot of cases not enqueued. If you enqueue events and never enqueue a Cti then StreamInsight will be perfectly happy. You, on the other hand, will never see data on the output as you have not told StreamInsight to flush the stream. This article deals with a specific implementation problem I had recently whilst working on a StreamInsight project. I look at some possible options and discuss why they would not work before showing the way I solved the problem. The stream of data I was dealing with on this project was very bursty that is to say when events were flowing they came through very quickly and in large numbers (1000 events/sec), but when the stream calmed down it could be a few seconds between each event. When enqueuing events into the StreamInsight engne it is best practice to do so with a StartTime that is given to you by the system producing the event . StreamInsight processes events and it doesn't matter whether those events are being pushed into the engine by a source system or the events are being read from something like a flat file in a directory somewhere. You can apply the same logic and temporal algebra to both situations. Reading from a file is an excellent example of where the time of the event on the source itself is very important. We could be reading that file a long time after it was written. Being able to read the StartTime from the events allows us to define windows that will hold the correct sets of events. I was able to do this with my stream but this is where my problems started. Below is a very simple script to create a SQL Server table and populate it with sample data that will show exactly the problem I had. CREATE TABLE [dbo].[t] ( [c1] [int] PRIMARY KEY, [c2] [datetime] NULL ) INSERT t VALUES (1,'20100810'),(2,'20100810'),(3,'20100810') Column c2 defines the StartTime of the event on the source and as you can see the values in all 3 rows of data is the same. If we read Ciprian’s articles we know that we can define how Ctis get injected into the stream in 3 different places The Stream Definition The Input Factory The Input Adapter I personally have always been a fan of enqueing Ctis through the factory. Below is code typical of what I would use to do this On the class itself I do some inheriting public class SimpleInputFactory : ITypedInputAdapterFactory<SimpleInputConfig>, ITypedDeclareAdvanceTimeProperties<SimpleInputConfig> And then I implement the following function public AdapterAdvanceTimeSettings DeclareAdvanceTimeProperties<TPayload>(SimpleInputConfig configInfo, EventShape eventShape) { return new AdapterAdvanceTimeSettings( new AdvanceTimeGenerationSettings(configInfo.CtiFrequency, TimeSpan.FromTicks(-1)), AdvanceTimePolicy.Adjust); } The configInfo .CtiFrequency property is a value I pass through to define after how many events I want a Cti to be injected and this in turn will flush through the stream of data. I usually pass a value of 1 for this setting. The second parameter determines the CTI timestamp in terms of a delay relative to the events. -1 ticks in the past results in 1 tick in the future, i.e., ahead of the event. The problem with this method though is that if consecutive events have the same StartTime then only one of those events will be enqueued. In this example I use the following to define how I assign the StartTime of my events currEvent.StartTime = (DateTimeOffset)dt.c2; If I go ahead and run my StreamInsight process with this configuration i can see on the output adapter that two events have been removed To see this in a little more depth I can use the StreamInsight Debugger and see what happens internally. What is happening here is that the first event arrives and a Cti is injected with a time of 1 tick after the StartTime of that event (Also the EndTime of the event). The second event arrives and it has a StartTime of before the Cti and even though we specified AdvanceTimePolicy.Adjust on the factory we know that a point event can never be adjusted like this and the event is dropped. The same happens for the third event as well (The second and third events get trumped by the Cti). For a more detailed discussion of why this happens look here http://www.sqlis.com/sqlis/post/AdvanceTimePolicy-and-Point-Event-Streams-In-StreamInsight.aspx We end up with a single event being pushed into the output adapter and our result now makes sense. The next way I tried to solve this problem by changing the value of the second parameter to TimeSpan.Zero Here is how my factory code now looks public AdapterAdvanceTimeSettings DeclareAdvanceTimeProperties<TPayload>(SimpleInputConfig configInfo, EventShape eventShape) { return new AdapterAdvanceTimeSettings( new AdvanceTimeGenerationSettings(configInfo.CtiFrequency, TimeSpan.Zero), AdvanceTimePolicy.Adjust); } What I am doing here is declaring a policy that says inject a Cti together with every event and stamp it with a StartTime that is equal to the start time of the event itself (TimeSpan.Zero). This method has plus points as well as a downside. The upside is that no events will be lost by having the same StartTime as previous events. The Downside is that because the Cti is declared with the StartTime of the event itself then it does not actually flush that particular event because in the StreamInsight algebra, a Cti commits only those events that occurred strictly before them. To flush the events we need a Cti to be enqueued with a greater StartTime than the events themselves. Here is what happened when I ran this configuration As you can see all we got through was the Cti and none of the events. The debugger output shows the stamps on the Cti and the events themselves. Because the Cti issued has the same timestamp (StartTime) as the events then none of the events get flushed. I was nearly there but not quite. Because my stream was bursty it was possible that the next event would not come along for a few seconds and this was far too long for an event to be enqueued and not be flushed to the output adapter. I needed another solution. Two possible solutions crossed my mind although only one of them made sense when I explored it some more. Where multiple events have the same StartTime I could add 1 tick to the first event, two to the second, three to third etc thereby giving them unique StartTime values. Add a timer to manually inject Ctis The problem with the first implementation is that I would be giving the events a new StartTime. This would cause me the following problems If I want to define windows over the stream then some events may not be captured in the right windows and therefore any calculations on those windows I did would be wrong What would happen if we had 10,000 events with the same StartTime? I would enqueue them with StartTime + n ticks. Along comes a genuine event with a StartTime of the very first event + 1 tick. It is now too far in the past as far as my stream is concerned and it would be dropped. Not what I would want to do at all. I decided then to look at the Timer based solution I created a timer on my input adapter that elapsed every 200ms. private Timer tmr; public SimpleInputAdapter(SimpleInputConfig configInfo) { ctx = new SimpleTimeExtractDataContext(configInfo.ConnectionString); this.configInfo = configInfo; tmr = new Timer(200); tmr.Elapsed += new ElapsedEventHandler(t_Elapsed); tmr.Enabled = true; } void t_Elapsed(object sender, ElapsedEventArgs e) { ts = DateTime.Now - dtCtiIssued; if (ts.TotalMilliseconds >= 200 && TimerIssuedCti == false) { EnqueueCtiEvent(System.DateTime.Now.AddTicks(-100)); TimerIssuedCti = true; } }   In the t_Elapsed event handler I find out the difference in time between now and when the last event was processed (dtCtiIssued). I then check to see if that is greater than or equal to 200ms and if the last issuing of a Cti was done by the timer or by a genuine event (TimerIssuedCti). If I didn’t do this check then I would enqueue a Cti every time the timer elapsed which is not something I wanted. If the difference between the two times is greater than or equal to 500ms and the last event enqueued was by a real event then I issue a Cti through the timer to flush the event Queue, otherwise I do nothing. When I enqueue the Ctis into my stream in my ProduceEvents method I also set the values of dtCtiIssued and TimerIssuedCti   currEvent = CreateInsertEvent(); currEvent.StartTime = (DateTimeOffset)dt.c2; TimerIssuedCti = false; dtCtiIssued = currEvent.StartTime; If I go ahead and run this configuration I see the following in my output. As we can see the first Cti gets enqueued as before but then another is enqueued by the timer and because this has a later timestamp it flushes the enqueued events through the engine. Conclusion Hopefully this has shown how the enqueuing of Ctis can have a dramatic effect on the responsiveness of your output in StreamInsight. Understanding the temporal nature of the product is for me one of the most important things you can learn. I have attached my solution for the demos. It is all in one project and testing each variation is a simple matter of commenting and un-commenting the parts in the code we have been dealing with here.

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• Accelerate your SOA with Data Integration - Live Webinar Tuesday!

  - by dain.hansen

  Need to put wind in your SOA sails? Organizations are turning more and more to Real-time data integration to complement their Service Oriented Architecture. The benefit? Lowering costs through consolidating legacy systems, reducing risk of bad data polluting their applications, and shortening the time to deliver new service offerings. Join us on Tuesday April 13th, 11AM PST for our live webinar on the value of combining SOA and Data Integration together. In this webcast you'll learn how to innovate across your applications swiftly and at a lower cost using Oracle Data Integration technologies: Oracle Data Integrator Enterprise Edition, Oracle GoldenGate, and Oracle Data Quality. You'll also hear: Best practices for building re-usable data services that are high performing and scalable across the enterprise How real-time data integration can maximize SOA returns while providing continuous availability for your mission critical applications Architectural approaches to speed service implementation and delivery times, with pre-integrations to CRM, ERP, BI, and other packaged applications Register now for this live webinar!

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• Jump-start Your Mind

  - by João Angelo

  I haven’t written in a while mostly because I’ve spent my time reading what others wrote and today I’m writing purely motivated by what I just finished reading. Mindfire: Big Ideas for Curious Mind by Scott Berkun was such a pleasure to read and ended up igniting parts of my mind which I have to admit were becoming a bit numb that I felt the urge to take some time to first say thank you to the author and then recommend it to all your curious minds out there. Now, go read it… it’s time well spent.

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• How much does it cost to develop an Android application?

  - by raychenon

  Following the same iPhone question. How much can a development team charge for an Android app like the official Twitter Inc ? In general how much amount of time is devoted to build the likes of Google Goggles , Google Skymap, Gmail with server side applications included :) Now if you're a solo developer and proud to show your app. How much time have you spent so far ? What was your background GUI desktop in Java, C#, web developer, started from zero programming experience ? Disclaimer : I've developed Android apps ( 10 000 downloads) on my free time and one commercial to be published. Just to know the amount of efforts needed to catch up :)

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• Becoming an expert vs boredom [closed]

  - by QAH

  I am a college student, and I love to program, period. I code all kinds of things in different kinds of languages. Although I enjoy programming, I have an extremely hard time sticking to one project for a long time. I attribute this shortcoming to my high level of curiosity, exploring different technologies, languages, libraries, etc. What would be best? Should I settle down more and spend time on becoming an expert in one or two programming fields, or should I be more of a jack of all trades, trying out all kinds of new technologies, languages, programming methods, etc.? I'm guessing that somewhere in the middle would be best. I'm always amazed at how many developers are able to create one or two projects, and develop on them for years. What techniques do you guys employ to help you stay focused on a project?

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• how do you spend your day? a day from a programmer's life [closed]

  - by RBA

  First of all I'm 26 and I'm asking this question because I want to see how do you manage your time. Also I'm interested how do the programmers with a family(wife, several kids) manage their time. I'm asking this due the fact that I'm working aprox 7,5 hours at work (9 to 5), spent 1,5 hours on the way to/from workplace, and when I'm home I must cook/clean/etc and LEARN! And I have the impression that I don't have enough time to learn. Did you have a period similar in your life? To want to learn another language/improve your development/other skills? I saw here and on SO that there are a lot of peoples with +10k points, this in my mind means that they stay on blogs/forums more than 15 hours a day. If you consider this question is a good question, please vote to reopen it. best regards, Radu

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• Insert text depending on time of day and day of week.

  - by ploughansen

  I'm trying to piece together a php script to output different text depending on what day it is and the time of day. Example: On weekdays (mon-fri), I would like to output text according to the following periods of time (24H, server time, UTC): 00:00-08:00: "Lorem ipsum" 08:00-13:00: "dolor sit amet" 13:00-15:00: "Pellentesque habitant" 15:00-15:30: "dolor sit amet" 15:30-24:00: "Lorem ipsum" On weekends (sat-sun), I would like to output the following text in this time period: 00:00-24:00 "Lorem ipsum" Can anyone help with a php script to do that? I've already gotten some help over at the css-tricks forum. They supplied this code: <?php $date = strtotime("now"); $hour = date("H", $date); switch($hour) { case 00: case 01: case 02: case 03: case 04: case 05: case 06: case 07: case 08: $dets = array("img" => "image1.png", "txt" => "Lorem ipsum"); break; case 09: case 10: case 11: case 12: case 13: $dets = array("img" => "image2.png", "txt" => "dolor sit amet"); break; case 14: case 15: case 16: $dets = array("img" => "image3.png", "txt" => "Pellentesque habitant"); break; case 17: case 18: case 19: case 20: case 21: case 22: case 23: case 24: $dets = array("img" => "image1.png", "txt" => "Lorem ipsum"); break; } echo "<img src='$dets[img]' alt='$dets[txt]' />"; ?> But it works for all days, and only in full hours. I want to be able to specify per half-hour and on a day to day basis. Still a php-noob so I'm hoping someone can help me.

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• SQL SERVER – Beginning SQL Server: One Step at a Time – SQL Server Magazine

  - by pinaldave

  I am glad to announce that along with SQLAuthority.com, I will be blogging on the prominent site of SQL Server Magazine. My very first blog post there is already live; read here: Beginning SQL Server: One Step at a Time. My association with SQL Server Magazine has been quite long, I have written nearly 7 to 8 SQL Server articles for the print magazine and it has been a great experience. I used to stay in the United States at that time. I moved back to India for good, and during this process, I had put everything on hold for a while. Just like many things, “temporary” things become “permanent” – coming back to SQLMag was on hold for long time. Well, this New Year, things have changed – once again, I am back with my online presence at SQLMag.com. Everybody is a beginner at every task or activity at some point of his/her life: spelling words for the first time; learning how to drive for the first time, etc. No one is perfect at the start of any task, but every human is different. As time passes, we all develop our interests and begin to study our subject of interest. Most of us dream to get a job in the area of our study – however things change as time passes. I recently read somewhere online (I could not find the link again while writing this one) that all the successful people in various areas have never studied in the area in which they are successful. After going through a formal learning process of what we love, we refuse to stop learning, and we finally stop changing career and focus areas. We move, we dare and we progress. IT field is similar to our life. New IT professionals come to this field every day. There are two types of beginners – a) those who are associated with IT field but not familiar with other technologies, and b) those who are absolutely new to the IT field. Learning a new technology is always exciting and overwhelming for enthusiasts. I am working with database (in particular) for SQL Server for more than 7 years but I am still overwhelmed with so many things to learn. I continue to learn and I do not think that I should ever stop doing so. Just like everybody, I want to be in the race and get ahead in learning the technology. For the same, I am always looking for good guidance. I always try to find a good article, blog or book chapter, which can teach me what I really want to learn at this stage in my career and can be immensely helpful. Quite often, I prefer to read the material where the author does not judge me or assume my understanding. I like to read new concepts like a child, who takes his/her first steps of learning without any prior knowledge. Keeping my personal philosophy and preference in mind, I will be blogging on SQL Server Magazine site. I will be blogging on the beginners stuff. I will be blogging for them, who really want to start and make a mark in this area. I will be blogging for all those who have an extreme passion for learning. I am happy that this is a good start for this year. One of my resolutions is to help every beginner. It is totally possible that in future they all will grow and find the same article quite ‘easy‘ – well when that happens, it indicates the success of the article and material! Well, I encourage everybody to read my SQL Server Magazine blog – I will be blogging there frequently on various topics. To begin, we will be talking about performance tuning, and I assure that I will not shy away from other multiple areas. Read my SQL Server Magazine Blog: Beginning SQL Server: One Step at a Time I think the title says it all. Do leave your comments and feedback to indicate your preference of subject and interest. I am going to continue writing on subject, and the aim is of course to help grow in this field. Reference : Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Optimization, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority News, T SQL, Technology

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• SQL SERVER – DATE and TIME in SQL Server 2008

  - by pinaldave

  I was thinking about DATE and TIME datatypes in SQL Server 2008. I earlier wrote about the about best practices of the same. Recently I had written one of the script written for SQL Server 2008 had to run on SQL Server 2005 (don’t ask me why!), I had to convert the DATE and TIME datatypes to DATETIME. Let me run quick demo for the same. DECLARE @varDate AS DATE DECLARE @varTime AS TIME SET @varDate = '10/10/2010' SET @varTime = '12:12:12' SELECT CAST(@varDate AS DATETIME) C_Date SELECT CAST(@varTime AS DATETIME) C_Time As seen in example when DATE is converted to DATETIME it adds the of midnight. When TIME is converted to DATETIME it adds the date of 1900 and it is something one wants to consider if you are going to run script from SQL Server 2008 to earlier version with CONVERT. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: SQL, SQL Authority, SQL DateTime, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• Root Access: Don Dodge talks to 3 time founder Jennifer Reuting of DocRun

  Root Access: Don Dodge talks to 3 time founder Jennifer Reuting of DocRun Three time startup founder Jennifer Reuting, CEO of DocRun, and author of LLCs for Dummies, sits down with Don Dodge to talk startups. Jennifer started her first company at 17 from the ashes of a failed company. Jennifer is revolutionizing the legal docs business with DocRun. Inspiring interview. From: GoogleDevelopers Views: 258 12 ratings Time: 44:37 More in Science & Technology

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• Date and Time Support in SQL Server 2008

  - by Aamir Hasan

    Using the New Date and Time Data Types Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} 1.       The new date and time data types in SQL Server 2008 offer increased range and precision and are ANSI SQL compatible. 2.       Separate date and time data types minimize storage space requirements for applications that need only date or time information. Moreover, the variable precision of the new time data type increases storage savings in exchange for reduced accuracy. 3.       The new data types are mostly compatible with the original date and time data types and use the same Transact-SQL functions. 4.       The datetimeoffset data type allows you to handle date and time information in global applications that use data that originates from different time zones. SELECT c.name, p.* FROM politics pJOIN country cON p.country = c.codeWHERE YEAR(Independence) < 1753ORDER BY IndependenceGO8.    Highlight the SELECT statement and click Execute ( ) to show the use of some of the date functions.T-SQLSELECT c.name AS [Country Name],        CONVERT(VARCHAR(12), p.Independence, 107) AS [Independence Date],       DATEDIFF(YEAR, p.Independence, GETDATE()) AS [Years Independent (appox)],       p.GovernmentFROM politics pJOIN country cON p.country = c.codeWHERE YEAR(Independence) < 1753ORDER BY IndependenceGO10.    Select the SET DATEFORMAT statement and click Execute ( ) to change the DATEFORMAT to day-month-year.T-SQLSET DATEFORMAT dmyGO11.    Select the DECLARE and SELECT statements and click Execute ( ) to show how the datetime and datetime2 data types interpret a date literal.T-SQLSET DATEFORMAT dmyDECLARE @dt datetime = '2008-12-05'DECLARE @dt2 datetime2 = '2008-12-05'SELECT MONTH(@dt) AS [Month-Datetime], DAY(@dt)     AS [Day-Datetime]SELECT MONTH(@dt2) AS [Month-Datetime2], DAY(@dt2)     AS [Day-Datetime2]GO12.    Highlight the DECLARE and SELECT statements and click Execute ( ) to use integer arithmetic on a datetime variable.T-SQLDECLARE @dt datetime = '2008-12-05'SELECT @dt + 1GO13.    Highlight the DECLARE and SELECT statements and click Execute ( ) to show how integer arithmetic is not allowed for datetime2 variables.T-SQLDECLARE @dt2 datetime = '2008-12-05'SELECT @dt2 + 1GO14.    Highlight the DECLARE and SELECT statements and click Execute ( ) to show how to use DATE functions to do simple arithmetic on datetime2 variables.T-SQLDECLARE @dt2 datetime2(7) = '2008-12-05'SELECT DATEADD(d, 1, @dt2)GO15.    Highlight the DECLARE and SELECT statements and click Execute ( ) to show how the GETDATE function can be used with both datetime and datetime2 data types.T-SQLDECLARE @dt datetime = GETDATE();DECLARE @dt2 datetime2(7) = GETDATE();SELECT @dt AS [GetDate-DateTime], @dt2 AS [GetDate-DateTime2]GO16.    Draw attention to the values returned for both columns and how they are equal.17.    Highlight the DECLARE and SELECT statements and click Execute ( ) to show how the SYSDATETIME function can be used with both datetime and datetime2 data types.T-SQLDECLARE @dt datetime = SYSDATETIME();DECLARE @dt2 datetime2(7) = SYSDATETIME();SELECT @dt AS [Sysdatetime-DateTime], @dt2     AS [Sysdatetime-DateTime2]GO18.    Draw attention to the values returned for both columns and how they are different.Programming Global Applications with DateTimeOffset 2.    If you have not previously created the SQLTrainingKitDB database while completing another demo in this training kit, highlight the CREATE DATABASE statement and click Execute ( ) to do so now.T-SQLCREATE DATABASE SQLTrainingKitDBGO3.    Select the USE and CREATE TABLE statements and click Execute ( ) to create table datetest in the SQLTrainingKitDB database.T-SQLUSE SQLTrainingKitDBGOCREATE TABLE datetest (  id integer IDENTITY PRIMARY KEY,  datetimecol datetimeoffset,  EnteredTZ varchar(40)); Reference:http://www.microsoft.com/downloads/details.aspx?FamilyID=E9C68E1B-1E0E-4299-B498-6AB3CA72A6D7&displaylang=en   

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