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• Principles of Big Data By Jules J Berman, O&rsquo;Reilly Media Book Review

  - by Compudicted

  Originally posted on: http://geekswithblogs.net/Compudicted/archive/2013/11/04/principles-of-big-data-by-jules-j-berman-orsquoreilly-media.aspx A fantastic book! Must be part, if not yet, of the fundamentals of the Big Data as a field of science. Highly recommend to those who are into the Big Data practice. Yet, I confess this book is one of my best reads this year and for a number of reasons: The book is full of wisdom, intimate insight, historical facts and real life examples to how Big Data projects get conceived, operate and sadly, yes, sometimes die. But not only that, the book is most importantly is filled with valuable advice, accurate and even overwhelming amount of reference (from the positive side), and the author does not event stop there: there are numerous technical excerpts, links and examples allowing to quickly accomplish many daunting tasks or make you aware of what one needs to perform as a data practitioner (excuse my use of the word practitioner, I just did not find a better substitute to it to trying to reference all who face Big Data). Be aware that Jules Berman’s background is in medicine, naturally, this book discusses this subject a lot as it is very dear to the author’s heart I believe, this does not make this book any less significant however, quite the opposite, I trust if there is an area in science or practice where the biggest benefits can be ripped from Big Data projects it is indeed the medical science, let’s make Cancer history! On a personal note, for me as a database, BI professional it has helped to understand better the motives behind Big Data initiatives, their underwater rivers and high altitude winds that divert or propel them forward. Additionally, I was impressed by the depth and number of mining algorithms covered in it. I must tell this made me very curious and tempting to find out more about these indispensable attributes of Big Data so sure I will be trying stretching my wallet to acquire several books that go more in depth on several most popular of them. My favorite parts of the book, well, all of them actually, but especially chapter 9: Analysis, it is just very close to my heart. But the real reason is it let me see what I do with data from a different angle. And then the next - “Special Considerations”, they are just two logical parts. The writing language is of this book is very acceptable for all levels, I had no technical problem reading it in ebook format on my 8” tablet or a large screen monitor. If I would be asked to say at least something negative I have to state I had a feeling initially that the book’s first part reads like an academic material relaxing the reader as the book progresses forward. I admit I am impressed with Jules’ abilities to use several programming languages and OSS tools, bravo! And I agree, it is not too, too hard to grasp at least the principals of a modern programming language, which seems becomes a defacto knowledge standard item for any modern human being. So grab a copy of this book, read it end to end and make yourself shielded from making mistakes at any stage of your Big Data initiative, by the way this book also helps build better future Big Data projects. Disclaimer: I received a free electronic copy of this book as part of the O'Reilly Blogger Program.

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• “I could use a little help here” or “I can do it myself, thank you” for Cloud Projects

  - by BuckWoody

  Windows Azure allows you to write code in languages within the .NET stack, you can use Java, C++, PHP, NodeJS and others. Code is code - other than keeping things stateless, using a Web or Worker Role in Azure is not all that different from working with an on-premises system. However…. Working in a scalable, component-based stateless architecture that can use federated security is not all that common for many developers. Some are used to owning the server, scaling up, and state-full paradigms that have a single security domain. Making the transition whilst trying to create a new software application or even port a previous one can be daunting. Sure, we have absolutely tons of free training, kits, videos, online books and more to learn on your own, but some things like architecture can be pivotal as you move along. So the question is, should you just strike out on your own for a Cloud project, or get Microsoft Consulting Services or another partner to work with you on your first one? I use a few decision points to help guide the projects I assist in. Note: I’m a huge fan of having help that ends up giving you training and leaves you in charge. If you do engage with someone to help you, make sure you keep this clear and take more and more ownership yourself as the project progresses. How much time do you have? Usually the first thing I ask is about the timeline for the project. It doesn’t matter how skilled you are, if you have a short window to get things done it’s better to get help - especially if this is your first cloud project. Having someone that knows the platform well can save you amazing amounts of time. If you have longer, then start with the training in the link above and once you feel confident, jump in. How complex is the project? If there are a lot of moving parts, it’s best to engage a partner. The reason is that certain interactions - particularly things like Service Bus or Data Integration  - can be quite different than what you may have encountered before. How many people do you have? I have a “pizza rule” about projects I’ve used in my career - if it takes over two pizzas to feed everyone on the project, it’s too big and will fail. That being said, one developer and a one-week deadline does not a good project make, usually. It’s best to have at least one architect (or someone in that role) guiding the project along, and at least two developers to work on a cloud project. That’s a generalization of course, since I’ve seen great software on Azure with one developer writing code all by herself, but for more complex projects, more (to a point) is better. The nice thing about bringing on a partner is that you don’t have to hire them full time - they help you and then they go away. How critical is the project? There’s no shame in using some help. If the platform is new, if the project is large and complex, and if it is critical to the business, you should engage a partner. That’s regardless of Cloud or anything else - get some help. You don’t want to hit your company’s bottom line in a negative way, but you have to innovate and get them a competitive advantage. Do your research, make sure the partner is qualified to help you, and get it done. Don’t let these questions scare you off. There are lots of projects you can implement on Windows and SQL Azure with nothing other than the Software Development Kit (SDK) that you get for free with Windows Azure. And assistance comes in many forms - sometimes just phone support, a friend you can ask. Microsoft Consulting Services or any of our great partners. You can get help on just the architecture piece or have them show you how to write the code. They’ll get involved as little or as much as you like.

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• Regular Expressions Cookbook Is in The Money—Win a Copy

  - by Jan Goyvaerts

  %COOKBOOKFRAME%You may have heard some people say that most book authors never get any royalties. That’s not true because most authors get an advance royalty that is paid before the book is published. That’s the author’s main incentive for writing the book, at least as far as money is concerned. (If money is your main concern, don’t write books.) What is true is that most authors never see any money beyond the advance royalty. Royalty rates are very low. A 10% royalty of the publisher’s price is considered normal. The publisher’s price is usually 45% of the retail price. So if you pay full price in a bookstore, the author gets 4.5% of your money. If there’s more than one author, they split the royalty. It doesn’t take a math degree to figure out that a book needs to sell quite a few copies for the royalty to add up to a meaningful amount of money. But Steven and I must have done something right. Regular Expressions Cookbook is in the money. My royalty statement for the 3rd quartier of 2009, which is the 2nd quarter that the book was on the market, came with a check. I actually received it last month but didn’t get around to blogging about. The amount of the check is insignificant. The point is that the balance is no longer negative. I’m taking this opportunity to pat myself and my co-author on the back. To celebrate the occassion O’Reilly has offered to sponsor a give-away of five (5) copies of Regular Expressions Cookbook. These are the rules of the game: You must post a comment to this blog article including your actual name and actual email address. Names are published, email addresses are not. Comments are moderated by myself (Jan Goyvaerts). If I consider a comment to be offensive or spam it will not be published and not be eligible for any prize. If you don’t know what to say in the comment, just wish me a happy 100000nd birthday, so I don’t have to feel so bad about entering the 6-bit era. Each person commenting has only one chance to win, regardless of the number of comments posted. O’Reilly will be provided with the names and email addresses of the winners (and those email addresses only) in order to arrange delivery. Each winner can choose to receive a printed copy or ebook (DRM-free PDF). If you choose the printed book, O’Reilly pays for shipping to anywhere in the world but not for any duties or taxes your country may impose on books imported from the USA. If you choose the ebook, you’ll need to create an O’Reilly account that is then granted access to the PDF download. You can make your choice after you’ve won, so it doesn’t influence your chance of winning. Contest ends 28 February 2010, GMT+7 (Thai time). Chosen by five calls to Random(78)+1 in Delphi 2010, the winners are: 48: Xiaozu 45: David Chisholm 19: Miquel Burns 33: Aaron Rice 17: David Laing Thanks to everybody who participated. The winners have been notified by email on how to collect their prize.

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• Big Data: Size isn’t everything

  - by Simon Elliston Ball

  Big Data has a big problem; it’s the word “Big”. These days, a quick Google search will uncover terabytes of negative opinion about the futility of relying on huge volumes of data to produce magical, meaningful insight. There are also many clichéd but correct assertions about the difficulties of correlation versus causation, in massive data sets. In reading some of these pieces, I begin to understand how climatologists must feel when people complain ironically about “global warming” during snowfall. Big Data has a name problem. There is a lot more to it than size. Shape, Speed, and…err…Veracity are also key elements (now I understand why Gartner and the gang went with V’s instead of S’s). The need to handle data of different shapes (Variety) is not new. Data developers have always had to mold strange-shaped data into our reporting systems, integrating with semi-structured sources, and even straying into full-text searching. However, what we lacked was an easy way to add semi-structured and unstructured data to our arsenal. New “Big Data” tools such as MongoDB, and other NoSQL (Not Only SQL) databases, or a graph database like Neo4J, fill this gap. Still, to many, they simply introduce noise to the clean signal that is their sensibly normalized data structures. What about speed (Velocity)? It’s not just high frequency trading that generates data faster than a single system can handle. Many other applications need to make trade-offs that traditional databases won’t, in order to cope with high data insert speeds, or to extract quickly the required information from data streams. Unfortunately, many people equate Big Data with the Hadoop platform, whose batch driven queries and job processing queues have little to do with “velocity”. StreamInsight, Esper and Tibco BusinessEvents are examples of Big Data tools designed to handle high-velocity data streams. Again, the name doesn’t do the discipline of Big Data any favors. Ultimately, though, does analyzing fast moving data produce insights as useful as the ones we get through a more considered approach, enabled by traditional BI? Finally, we have Veracity and Value. In many ways, these additions to the classic Volume, Velocity and Variety trio acknowledge the criticism that without high-quality data and genuinely valuable outputs then data, big or otherwise, is worthless. As a discipline, Big Data has recognized this, and data quality and cleaning tools are starting to appear to support it. Rather than simply decrying the irrelevance of Volume, we need as a profession to focus how to improve Veracity and Value. Perhaps we should just declare the ‘Big’ silent, embrace these new data tools and help develop better practices for their use, just as we did the good old RDBMS? What does Big Data mean to you? Which V gives your business the most pain, or the most value? Do you see these new tools as a useful addition to the BI toolbox, or are they just enabling a dangerous trend to find ghosts in the noise?

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• AutoFit in PowerPoint: Turn it OFF

  - by Daniel Moth

  Once a feature has shipped, it is very hard to eliminate it from the next release. If I was in charge of the PowerPoint product, I would not hesitate for a second to remove the dreadful AutoFit feature. Fortunately, AutoFit can be turned off on a slide-by-slide basis and, even better, globally: go to the PowerPoint "Options" and under "Proofing" find the "AutoCorrect Options…" button which brings up the dialog where you need to uncheck the last two checkboxes (see the screenshot to the right). AutoFit is the ability for the user to keep hitting the Enter key as they type more and more text into a slide and it magically still fits, by shrinking the space between the lines and then the text font size. It is the root of all slide evil. It encourages people to think of a slide as a Word document (which may be your goal, if you are presenting to execs in Microsoft, but that is a different story). AutoFit is the reason you fall asleep in presentations. AutoFit causes too much text to appear on a slide which by extension causes the following: When the slide appears, the text is so small so it is not readable by everyone in the audience. They dismiss the presenter as someone who does not care for them and then they stop paying attention. If the text is readable, but it is too much (hence the AutoFit feature kicked in when the slide was authored), the audience is busy reading the slide and not paying attention to the presenter. Humans can either listen well or read well at the same time, so when they are done reading they now feel that they missed whatever the speaker was saying. So they "switch off" for the rest of the slide until the next slide kicks in, which is the natural point for them to pick up paying attention again. Every slide ends up with different sized text. The less visual consistency between slides, the more your presentation feels unprofessional. You can do better than dismiss the (subconscious) negative effect a deck with inconsistent slides has on an audience. In contrast, the absence of AutoFit Leads to consistency among all slides in a deck with regards to amount of text and size of said text. Ensures the text is readable by everyone in the audience (presuming the PowerPoint template is designed for the room where the presentation is delivered). Encourages the presenter to create slides with the minimum necessary text to help the audience understand the basic structure, flow, and key points of the presentation. The "meat" of the presentation is delivered verbally by the presenter themselves, which is why they are in the room in the first place. Following on from the previous point, the audience can at a quick glance consume the text on the slide when it appears and then concentrate entirely on the presenter and what they have to say. You could argue that everything above has nothing to do with the AutoFit feature and all to do with the advice to keep slide content short. You would be right, but the on-by-default AutoFit feature is the one that stops most people from seeing and embracing that truth. In other words, the slides are the tool that aids the presenter in delivering their message, instead of the presenter being the tool that advances the slides which hold the message. To get there, embrace terse slides: the first step is to turn off this horrible feature (that was probably introduced due to the misuse of this tool within Microsoft). The next steps are described on my next post. Comments about this post welcome at the original blog.

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• Release Management as Orchestra

  - by ericajanine

  I read an excellent, concise article (http://www.buildmeister.com/articles/software_release_management_best_practices) on the basics of release management practices. In the article, it states "Release Management is often likened to the conductor of an orchestra, with the individual changes to be implemented the various instruments within it." I played in music ensembles for years, so this is especially close to my heart as example. I learned most of my discipline from hours and hours of practice at the hand of a very skilled conductor and leader. I also learned that the true magic in symphonic performance is one where everyone involved is focused on one sound, one goal. In turn, that solid focus creates a sound and experience bigger than just mechanics alone accomplish. In symphony, a conductor's true purpose is to make you, a performer, better so the overall sound and end product is better. The big picture (the performance of the composition) is the end-game, and all musicians in the orchestra know without question their part makes up an important but incomplete piece of that performance. A good conductor works with each section (e.g. group) to ensure their individual pieces are solid. Let's restate: The conductor leads and is responsible for ensuring those pieces are solid. While the performers themselves are doing the work, the conductor is the final authority on when the pieces are ready or not. If not, the conductor initiates the efforts to get them ready or makes the decision to scrap their parts altogether for the sake of an overall performance. Let it sink in, because it's clear--It is not the performer's call if they play their part as agreed, it's the conductor's final call to allow it. In comparison, if a software release manager is a conductor, the only way for that manager to be effective is to drive the overarching process and execution of individual pieces of a software development lifecycle. It does not mean the release manager performs each and every piece, it means the release manager has oversight and influence because the end-game is a successful software enhancin a useable environment. It means the release manager, not the developer or development manager, has the final call if something goes into a software release. Of course, this is not a process of autocracy or dictation of absolute rule, it's cooperative effort. But the release manager must have the final authority to make a decision if something is ready to be added to the bigger piece, the overall symphony of software changes being considered for package and release. It also goes without saying a release manager, like a conductor, must have full autonomy and isolation from other software groups. A conductor is the one on the podium waving a little stick at the each section and cueing them for their parts, not yelling from the back of the room while also playing a tuba and taking direction from the horn section. I have personally seen where release managers are relegated to being considered little more than coordinators, red-tapers to "satisfy" the demands of an audit group without being bothered to actually respect all that a release manager gives a group willing to employ them fully. In this dysfunctional scenario, development managers, project managers, business users, and other stakeholders have been given nearly full clearance to demand and push their agendas forward, causing a tail-wagging-the-dog scenario where an inherent conflict will ensue. Depending on the strength, determination for peace, and willingness to overlook a built-in expectation that is wrong, the release manager here must face the crafted conflict head-on and diffuse it as quickly as possible. Then, the release manager must clearly make a case why a change cannot be released without negative impact to all parties involved. If a political agenda is solely driving a software release, there IS no symphony, there is no "software lifecycle". It's just out-of-tune noise. More importantly, there is no real conductor. Sometimes, just wanting to make a beautiful sound is not enough. If you are a release manager, are you freed up enough to move, to conduct the sections of software creation to ensure a solid release performance is possible? If not, it's time to take stock in what your role actually is and see if that is what you truly want to achieve in your position. If you are, then you can successfully build your career and that of the people in your groups to create truly beautiful software (music) together.

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• AutoFit in PowerPoint: Turn it OFF

  - by Daniel Moth

  Once a feature has shipped, it is very hard to eliminate it from the next release. If I was in charge of the PowerPoint product, I would not hesitate for a second to remove the dreadful AutoFit feature. Fortunately, AutoFit can be turned off on a slide-by-slide basis and, even better, globally: go to the PowerPoint "Options" and under "Proofing" find the "AutoCorrect Options…" button which brings up the dialog where you need to uncheck the last two checkboxes (see the screenshot to the right). AutoFit is the ability for the user to keep hitting the Enter key as they type more and more text into a slide and it magically still fits, by shrinking the space between the lines and then the text font size. It is the root of all slide evil. It encourages people to think of a slide as a Word document (which may be your goal, if you are presenting to execs in Microsoft, but that is a different story). AutoFit is the reason you fall asleep in presentations. AutoFit causes too much text to appear on a slide which by extension causes the following: When the slide appears, the text is so small so it is not readable by everyone in the audience. They dismiss the presenter as someone who does not care for them and then they stop paying attention. If the text is readable, but it is too much (hence the AutoFit feature kicked in when the slide was authored), the audience is busy reading the slide and not paying attention to the presenter. Humans can either listen well or read well at the same time, so when they are done reading they now feel that they missed whatever the speaker was saying. So they "switch off" for the rest of the slide until the next slide kicks in, which is the natural point for them to pick up paying attention again. Every slide ends up with different sized text. The less visual consistency between slides, the more your presentation feels unprofessional. You can do better than dismiss the (subconscious) negative effect a deck with inconsistent slides has on an audience. In contrast, the absence of AutoFit Leads to consistency among all slides in a deck with regards to amount of text and size of said text. Ensures the text is readable by everyone in the audience (presuming the PowerPoint template is designed for the room where the presentation is delivered). Encourages the presenter to create slides with the minimum necessary text to help the audience understand the basic structure, flow, and key points of the presentation. The "meat" of the presentation is delivered verbally by the presenter themselves, which is why they are in the room in the first place. Following on from the previous point, the audience can at a quick glance consume the text on the slide when it appears and then concentrate entirely on the presenter and what they have to say. You could argue that everything above has nothing to do with the AutoFit feature and all to do with the advice to keep slide content short. You would be right, but the on-by-default AutoFit feature is the one that stops most people from seeing and embracing that truth. In other words, the slides are the tool that aids the presenter in delivering their message, instead of the presenter being the tool that advances the slides which hold the message. To get there, embrace terse slides: the first step is to turn off this horrible feature (that was probably introduced due to the misuse of this tool within Microsoft). The next steps are described on my next post. Comments about this post welcome at the original blog.

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• How to develop RPG Damage Formulas?

  - by user127817

  I'm developing a classical 2d RPG (in a similar vein to final fantasy) and I was wondering if anyone had some advice on how to do damage formulas/links to resources/examples? I'll explain my current setup. Hopefully I'm not overdoing it with this question, and I apologize if my questions is too large/broad My Characters stats are composed of the following: enum Stat { HP = 0, MP = 1, SP = 2, Strength = 3, Vitality = 4, Magic = 5, Spirit = 6, Skill = 7, Speed = 8, //Speed/Agility are the same thing Agility = 8, Evasion = 9, MgEvasion = 10, Accuracy = 11, Luck = 12, }; Vitality is basically defense to physical attacks and spirit is defense to magic attacks. All stats have fixed maximums (9999 for HP, 999 for MP/SP and 255 for the rest). With abilities, the maximums can be increased (99999 for HP, 9999 for HP/SP, 999 for the rest) with typical values (at level 100) before/after abilities+equipment+etc will be 8000/20,000 for HP, 800/2000 for SP/MP, 180/350 for other stats Late game Enemy HP will typically be in the lower millions (with a super boss having the maximum of ~12 million). I was wondering how do people actually develop proper damage formulas that scale correctly? For instance, based on this data, using the damage formulas for Final Fantasy X as a base looked very promising. A full reference here http://www.gamefaqs.com/ps2/197344-final-fantasy-x/faqs/31381 but as a quick example: Str = 127, 'Attack' command used, enemy Def = 34. 1. Physical Damage Calculation: Step 1 ------------------------------------- [{(Stat^3 ÷ 32) + 32} x DmCon ÷16] Step 2 ---------------------------------------- [{(127^3 ÷ 32) + 32} x 16 ÷ 16] Step 3 -------------------------------------- [{(2048383 ÷ 32) + 32} x 16 ÷ 16] Step 4 --------------------------------------------------- [{(64011) + 32} x 1] Step 5 -------------------------------------------------------- [{(64043 x 1)}] Step 6 ---------------------------------------------------- Base Damage = 64043 Step 7 ----------------------------------------- [{(Def - 280.4)^2} ÷ 110] + 16 Step 8 ------------------------------------------ [{(34 - 280.4)^2} ÷ 110] + 16 Step 9 ------------------------------------------------- [(-246)^2) ÷ 110] + 16 Step 10 ---------------------------------------------------- [60516 ÷ 110] + 16 Step 11 ------------------------------------------------------------ [550] + 16 Step 12 ---------------------------------------------------------- DefNum = 566 Step 13 ---------------------------------------------- [BaseDmg * DefNum ÷ 730] Step 14 --------------------------------------------------- [64043 * 566 ÷ 730] Step 15 ------------------------------------------------------ [36248338 ÷ 730] Step 16 ------------------------------------------------- Base Damage 2 = 49655 Step 17 ------------ Base Damage 2 * {730 - (Def * 51 - Def^2 ÷ 11) ÷ 10} ÷ 730 Step 18 ---------------------- 49655 * {730 - (34 * 51 - 34^2 ÷ 11) ÷ 10} ÷ 730 Step 19 ------------------------- 49655 * {730 - (1734 - 1156 ÷ 11) ÷ 10} ÷ 730 Step 20 ------------------------------- 49655 * {730 - (1734 - 105) ÷ 10} ÷ 730 Step 21 ------------------------------------- 49655 * {730 - (1629) ÷ 10} ÷ 730 Step 22 --------------------------------------------- 49655 * {730 - 162} ÷ 730 Step 23 ----------------------------------------------------- 49655 * 568 ÷ 730 Step 24 -------------------------------------------------- Final Damage = 38635 I simply modified the dividers to include the attack rating of weapons and the armor rating of armor. Magic Damage is calculated as follows: Mag = 255, Ultima is used, enemy MDef = 1 Step 1 ----------------------------------- [DmCon * ([Stat^2 ÷ 6] + DmCon) ÷ 4] Step 2 ------------------------------------------ [70 * ([255^2 ÷ 6] + 70) ÷ 4] Step 3 ------------------------------------------ [70 * ([65025 ÷ 6] + 70) ÷ 4] Step 4 ------------------------------------------------ [70 * (10837 + 70) ÷ 4] Step 5 ----------------------------------------------------- [70 * (10907) ÷ 4] Step 6 ------------------------------------ Base Damage = 190872 [cut to 99999] Step 7 ---------------------------------------- [{(MDef - 280.4)^2} ÷ 110] + 16 Step 8 ------------------------------------------- [{(1 - 280.4)^2} ÷ 110] + 16 Step 9 ---------------------------------------------- [{(-279.4)^2} ÷ 110] + 16 Step 10 -------------------------------------------------- [(78064) ÷ 110] + 16 Step 11 ------------------------------------------------------------ [709] + 16 Step 12 --------------------------------------------------------- MDefNum = 725 Step 13 --------------------------------------------- [BaseDmg * MDefNum ÷ 730] Step 14 --------------------------------------------------- [99999 * 725 ÷ 730] Step 15 ------------------------------------------------- Base Damage 2 = 99314 Step 16 ---------- Base Damage 2 * {730 - (MDef * 51 - MDef^2 ÷ 11) ÷ 10} ÷ 730 Step 17 ------------------------ 99314 * {730 - (1 * 51 - 1^2 ÷ 11) ÷ 10} ÷ 730 Step 18 ------------------------------ 99314 * {730 - (51 - 1 ÷ 11) ÷ 10} ÷ 730 Step 19 --------------------------------------- 99314 * {730 - (49) ÷ 10} ÷ 730 Step 20 ----------------------------------------------------- 99314 * 725 ÷ 730 Step 21 -------------------------------------------------- Final Damage = 98633 The problem is that the formulas completely fall apart once stats start going above 255. In particular Defense values over 300 or so start generating really strange behavior. High Strength + Defense stats lead to massive negative values for instance. While I might be able to modify the formulas to work correctly for my use case, it'd probably be easier just to use a completely new formula. How do people actually develop damage formulas? I was considering opening excel and trying to build the formula that way (mapping Attack Stats vs. Defense Stats for instance) but I was wondering if there's an easier way? While I can't convey the full game mechanics of my game here, might someone be able to suggest a good starting place for building a damage formula? Thanks

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• Help finding time of collision

  - by WannaBe

  I am making a simple game right now and am struggling with collision response. My goal is to someday be able to turn it into a 2D platformer but I have a long way to go. I am currently making this in JavaScript and using the canvas element so (0,0) is in the top left and positive X is to the right and positive Y is down. I read a helpful post on StackExchange that got me started on this but I can't seem to get the algorithm 100% correct. How to deal with corner collisions in 2D? I can detect the collision fine but I can't seem to get the response right. The goal is to detect which side the player hit first since minimum displacement doesn't always work. The X response seems to work fine but the Y only works when I am far from the corners. Here is a picture showing what happens Here is the code var bx = box.x; var by = box.y; var bw = box.width; var bh = box.height; var boxCenterX = bx + (bw/2); var boxCenterY = by + (bh/2); var playerCenterX = player.x + player.xvel + (player.width/2); var playerCenterY = player.y + player.yvel + (player.height/2); //left = negative and right = positve, 0 = middle var distanceXin = playerCenterX - boxCenterX; var distanceYin = playerCenterY - boxCenterY; var distanceWidth = Math.abs(distanceXin); var distanceHeight = Math.abs(distanceYin); var halfWidths = (bw/2) + (player.width/2); var halfHeights = (bh/2) + (player.height/2); if(distanceWidth < halfWidths){ //xcollision if(distanceHeight < halfHeights){ //ycollision if(player.xvel == 0){ //adjust y if(distanceYin > 0){ //bottom player.y = by + bh; player.yvel = 0; }else{ player.y = by - player.height; player.yvel = 0; } }else if(player.yvel == 0){ //adjust x if(distanceXin > 0){ //right player.x = bx + bw; player.xvel = 0; }else{ //left player.x = bx - player.width; player.xvel = 0; } }else{ var yTime = distanceYin / player.yvel; var xTime = distanceXin / player.xvel; if(xTime < yTime){ //adjust the x it collided first if(distanceXin > 0){ //right player.x = bx + bw; player.xvel = 0; }else{ //left player.x = bx - player.width; player.xvel = 0; } }else{ //adjust the y it collided first if(distanceYin > 0){ //bottom player.y = by + bh; player.yvel = 0; }else{ player.y = by - player.height; player.yvel = 0; } } } } } And here is a JSFiddle if you would like to see the problem yourself. http://jsfiddle.net/dMumU/ To recreate this move the player to here And press up and left at the same time. The player will jump to the right for some reason. Any advice? I know I am close but I can't seem to get xTime and yTime to equal what I want every time.

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• How can we improve overall Programmer Education & Training?

  - by crosenblum

  Last week, I was just viewing this amazing interview by Kevin Rose of Phillip Rosedale, of Second Life. And they had an amazing discussion about how to find, hire and identify good programmer's, and how hard it is to find good ones. Which has lead me to really think about the way we programmer's learn, are taught. For a majority of us, myself included, we are self-taught. Which is great about being a programmer, anyone can learn and develop skills. But this also means, that there is no real standards of what a good programmer is/are, and what kind of environment's encourage the growth of programming skills. This isn't so much a question, but just a desire in me, to see how we can change the culture of programming, and the manager's of programming, so that education and self-improvement is encouraged. There are a lot of avenue's for continued education, youtube videos, books, conferences, but because of the experiental nature of what we do, it isn't always clear what's important to learn and to master. Let's look at the The Joel 12 Steps. The Joel Test Do you use source control? Can you make a build in one step? Do you make daily builds? Do you have a bug database? Do you fix bugs before writing new code? Do you have an up-to-date schedule? Do you have a spec? Do programmers have quiet working conditions? Do you use the best tools money can buy? Do you have testers? Do new candidates write code during their interview? Do you do hallway usability testing? I think all of these have important value, but because of something I call the Experiential Gap, if a programmer or manager has never experienced any of the negative consequences for not having done items on the list, they will never see the need to do any of them. The Experiental Gap, is my basic theory, that each of us has different jobs and different experiences. So for some of us, that have always worked with dozens of programmer's, source control is a must have. But for people who have always been the only programmer, they can not imagine the need for source control. And it's because of this major flaw in how we learn, that we evaluate people by what best practices they do or not do, and the reason for either can start a flame war. We always evaluate people in our field by what they do, and think "Oh if this guy/gal isn't doing xyz best practice, he/she can't be a good programmer, so let's not waste time or energy talking to them." This is exactly why we have so many programming flame wars, that it becomes, because of the Experiental Gap, we can't imagine people not having made the decisions that we have had to made. So this has lead me to think, that we totally need to rethink how we train, educate and manage programmer's. For example, what percentage of you have had encouragement by your manager's to go to conferences, and even have them pay for it? For me, and a lot of people, this is extremely rare, a lot of us would love to go to conferences, to learn more, but the money ain't there to do that. So the point of this question is really to spark a lot of how can we train, learn and manage better? How can we create a new culture of learning that doesn't insult people for not having the same job experiences. Yes we all have jobs and work to do, but our ability to do our jobs well, depends on our desire, interest and support in improving our mastery of our skills. Right now, I see our culture being rather disorganized, we support the elite, but those tons of us that want to get better, just don't have enough support to learn and improve ourselves. I mean, do we as an industry, want to be perceived as just replaceable cogs? Thank you...

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• HSSFS Part 2.1 - Parsing @@VERSION

  - by Most Valuable Yak (Rob Volk)

  For Part 2 of the Handy SQL Server Function Series I decided to tackle parsing useful information from the @@VERSION function, because I am an idiot.  It turns out I was confused about CHARINDEX() vs. PATINDEX() and it pretty much invalidated my original solution.  All is not lost though, this mistake turned out to be informative for me, and hopefully for you. Referring back to the "Version" view in the prelude I started with the following query to extract the version number: SELECT DISTINCT SQLVersion, SUBSTRING(VersionString,PATINDEX('%-%',VersionString)+2, 12) VerNum FROM VERSION I used PATINDEX() to find the first hyphen "-" character in the string, since the version number appears 2 positions after it, and got these results: SQLVersion VerNum ----------- ------------ 2000 8.00.2055 (I 2005 9.00.3080.00 2005 9.00.4053.00 2008 10.50.1600.1 As you can see it was good enough for most of the values, but not for the SQL 2000 @@VERSION.  You'll notice it has only 3 version sections/octets where the others have 4, and the SUBSTRING() grabbed the non-numeric characters after.  To properly parse the version number will require a non-fixed value for the 3rd parameter of SUBSTRING(), which is the number of characters to extract. The best value is the position of the first space to occur after the version number (VN), the trick is to figure out how to find it.  Here's where my confusion about PATINDEX() came about.  The CHARINDEX() function has a handy optional 3rd parameter: CHARINDEX (expression1 ,expression2 [ ,start_location ] ) While PATINDEX(): PATINDEX ('%pattern%',expression ) Does not.  I had expected to use PATINDEX() to start searching for a space AFTER the position of the VN, but it doesn't work that way.  Since there are plenty of spaces before the VN, I thought I'd try PATINDEX() on another character that doesn't appear before, and tried "(": SELECT SQLVersion, SUBSTRING(VersionString,PATINDEX('%-%',VersionString)+2, PATINDEX('%(%',VersionString)) FROM VERSION Unfortunately this messes up the length calculation and yields: SQLVersion VerNum ----------- --------------------------- 2000 8.00.2055 (Intel X86) Dec 16 2008 19:4 2005 9.00.3080.00 (Intel X86) Sep 6 2009 01: 2005 9.00.4053.00 (Intel X86) May 26 2009 14: 2008 10.50.1600.1 (Intel X86) Apr 2008 10.50.1600.1 (X64) Apr 2 20 Yuck.  The problem is that PATINDEX() returns position, and SUBSTRING() needs length, so I have to subtract the VN starting position: SELECT SQLVersion, SUBSTRING(VersionString,PATINDEX('%-%',VersionString)+2, PATINDEX('%(%',VersionString)-PATINDEX('%-%',VersionString)) VerNum FROM VERSION And the results are: SQLVersion VerNum ----------- -------------------------------------------------------- 2000 8.00.2055 (I 2005 9.00.4053.00 (I Msg 537, Level 16, State 2, Line 1 Invalid length parameter passed to the LEFT or SUBSTRING function. Ummmm, whoops.  Turns out SQL Server 2008 R2 includes "(RTM)" before the VN, and that causes the length to turn negative. So now that that blew up, I started to think about matching digit and dot (.) patterns.  Sadly, a quick look at the first set of results will quickly scuttle that idea, since different versions have different digit patterns and lengths. At this point (which took far longer than I wanted) I decided to cut my losses and redo the query using CHARINDEX(), which I'll cover in Part 2.2.  So to do a little post-mortem on this technique: PATINDEX() doesn't have the flexibility to match the digit pattern of the version number; PATINDEX() doesn't have a "start" parameter like CHARINDEX(), that allows us to skip over parts of the string; The SUBSTRING() expression is getting pretty complicated for this relatively simple task! This doesn't mean that PATINDEX() isn't useful, it's just not a good fit for this particular problem.  I'll include a version in the next post that extracts the version number properly. UPDATE: Sorry if you saw the unformatted version of this earlier, I'm on a quest to find blog software that ACTUALLY WORKS.

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• St. Louis ALT.NET

  - by Brian Schroer

  I’m a huge fan of the St. Louis .NET User Group and a regular attendee of their meetings, but always wished there was a local group that discussed more advanced .NET topics. (That’s not a criticism of the group - I appreciate that they want to server developers with a broad range of skill levels). That’s why I was thrilled when Nicholas Cloud started a St. Louis ALT.NET group in 2010. Here’s the “about us” statement from the group’s web site: The ALT.NET community is a loosely coupled, highly cohesive group of like-minded individuals who believe that the best developers do not align themselves with platforms and languages, but with principles and ideas. In 2007, David Laribee created the term "ALT.NET" to explain this "alternative" view of the Microsoft development universe--a view that challenged the "Microsoft-only" approach to software development. He distilled his thoughts into four key developer characteristics which form the basis of the ALT.NET philosophy: You're the type of developer who uses what works while keeping an eye out for a better way. You reach outside the mainstream to adopt the best of any community: Open Source, Agile, Java, Ruby, etc. You're not content with the status quo. Things can always be better expressed, more elegant and simple, more mutable, higher quality, etc. You know tools are great, but they only take you so far. It's the principles and knowledge that really matter. The best tools are those that embed the knowledge and encourage the principles (e.g. Resharper.) The St. Louis ALT.NET meetup group is a place where .NET developers can learn, share, and critique approaches to software development on the .NET stack. We cater to the highest common denominator, not the lowest, and want to help all St. Louis .NET developers achieve a superior level of software craftsmanship. I don’t see a lot of ALT.NET talk in blogs these days. The movement was harmed early on by the negative attitudes of some of its early leaders, including jerk moves like the Entity Framework “vote of no confidence”, but I do see occasional mentions of local groups like the St. Louis one. I think ALT.NET has been successful at bringing some of its ideas into the .NET world, including heavily influencing ASP.NET MVC and raising the general level of software craftsmanship for developers working on the Microsoft stack. The ideas and ideals live on, they’re just not branded as “this is ALT.NET!” In the past 18 months, St. Louis ALT.NET meetups have discussed topics like: NHibernate F# and other functional languages AOP CoffeeScript “How Ruby Is Making Me a Stronger C# Developer” Using rake for builds CQRS .NET dynamic programming micro web frameworks – Nancy & Jessica Git ALT.NET doesn’t mean (to me, anyway) “alternatives to .NET”, but “alternatives for .NET”. We look at how things are done in Ruby and other languages/platforms, but always with the idea “What can I learn from this to take back to my “day job” with .NET?”. Meetings are held at 7PM on the fourth Wednesday of each month at the offices of Professional Employment Group. PEG is located at 999 Executive Parkway (Suite 100 – lower level) in Creve Coeur (South of Olive off of Mason Road - Here's a map). Food is not supplied (sorry if you’re a big fan of the Papa John’s Crust-Lovers’ Pizza that’s a staple of user group meetings), but attendees are encouraged to come early and bring/share beer, so that’s cool. Thanks to Nick for organizing, and to Professional Employment Group for lending their offices. Please visit the meetup site for more information.

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• Sorry about the wait.

  - by Ratman21

  In the last two days have been trying remove “Iolo System Mechanic Professional” (With anti-virus and FireWall) from 3 of the 5 pc’s we have (3 lap tops and two Desk tops) as it was going to expire on the 13th.   So I could replace them with a free anti-virus (AVG) and just use the windows fire wall. I have been using the same set up on one of my desk tops (XP Pro) for 8 months and one of the Lap tops (Vista) for 5 months.   The problem was that System Mechanic did not want to go. Even after using the uninstall option on the desk top (my main PC, well its that because has the larger of all the PC’s hard drives but, is the oldest and runs XP home) and using Ccleaner to try and remove it.  It was still showing up as there and after I went a head and tried installing AVG and ran it. I found that the TCP/IP module was missing.  So no internet, I had to restore the PC back to the 1st to get the module back and then install AVG (after making sure window firewall was back on. I didn’t check that on the first try). Got the PC back to normal, very late last night. Only one of the two lap tops was easy but, even at that there are still some parts of System Mechanic on it but, AVG and firewall are working.   I may try an hunt down parts of System Mechanic on it and delete them on this lap top. Which was what finally had to do on the one of the Lap tops (also XP Home) as it would not uninstall after I restored the PC back to the 4th. So delete, delete, delete and Ccleaner (one dl file would not delete though). And I just finish installing AVG and now running a scan on the lap top. So all of this took two days (well three counting today). I started late Friday night and just finishing up now.   I only started this switch over after I had finished my Job search for day on Friday.   As for blogging on Tuesday, Wednesday and Thursday, I was busy and by the end of the day was too tired to blog, that and was hung up still on that 2nd dare of The Love Dare. So I cleaned the house, while she was out of the house. I mean, I cleaned, not just vacuumed house I cleaned the kitchen counter tops and the sinks. Did the dishes and some of the laundry over two of the those days.   As to the third day of Love Dare which is “Love is not selfish” and the dare “Whatever you put your time, energy, and money into will become more important to you. It’s hard to care for something you are not investing in. Along with restraining from negative comments, buy your spouse something that says, I was thinking of you today.”   Being on a very limited income, a lot of normal guy buying for girls is out (for one thing, the comment why did you waste our money on flowers, etc, etc, would come up. Not from me though). So that one is on hold till money issues are not a problem (no that does not mean never). The 4th day “Love is thoughtful” and the dare “Contact your spouse sometime during the business of the day. Have no agenda other than asking how he or she is doing and if there is anything you could do for them”.   I did this dare while I was still working with census last week and trying to do the dares. Well I start my CCNA classes Monday the 15th and I move on to the next Love Dare day “Love is not rude”.

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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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• Improvements to Joshua Bloch's Builder Design Pattern?

  - by Jason Fotinatos

  Back in 2007, I read an article about Joshua Blochs take on the "builder pattern" and how it could be modified to improve the overuse of constructors and setters, especially when an object has a large number of properties, most of which are optional. A brief summary of this design pattern is articled here [http://rwhansen.blogspot.com/2007/07/theres-builder-pattern-that-joshua.html]. I liked the idea, and have been using it since. The problem with it, while it is very clean and nice to use from the client perspective, implementing it can be a pain in the bum! There are so many different places in the object where a single property is reference, and thus creating the object, and adding a new property takes a lot of time. So...I had an idea. First, an example object in Joshua Bloch's style: Josh Bloch Style: public class OptionsJoshBlochStyle { private final String option1; private final int option2; // ...other options here <<<< public String getOption1() { return option1; } public int getOption2() { return option2; } public static class Builder { private String option1; private int option2; // other options here <<<<< public Builder option1(String option1) { this.option1 = option1; return this; } public Builder option2(int option2) { this.option2 = option2; return this; } public OptionsJoshBlochStyle build() { return new OptionsJoshBlochStyle(this); } } private OptionsJoshBlochStyle(Builder builder) { this.option1 = builder.option1; this.option2 = builder.option2; // other options here <<<<<< } public static void main(String[] args) { OptionsJoshBlochStyle optionsVariation1 = new OptionsJoshBlochStyle.Builder().option1("firefox").option2(1).build(); OptionsJoshBlochStyle optionsVariation2 = new OptionsJoshBlochStyle.Builder().option1("chrome").option2(2).build(); } } Now my "improved" version: public class Options { // note that these are not final private String option1; private int option2; // ...other options here public String getOption1() { return option1; } public int getOption2() { return option2; } public static class Builder { private final Options options = new Options(); public Builder option1(String option1) { this.options.option1 = option1; return this; } public Builder option2(int option2) { this.options.option2 = option2; return this; } public Options build() { return options; } } private Options() { } public static void main(String[] args) { Options optionsVariation1 = new Options.Builder().option1("firefox").option2(1).build(); Options optionsVariation2 = new Options.Builder().option1("chrome").option2(2).build(); } } As you can see in my "improved version", there are 2 less places in which we need to add code about any addition properties (or options, in this case)! The only negative that I can see is that the instance variables of the outer class are not able to be final. But, the class is still immutable without this. Is there really any downside to this improvement in maintainability? There has to be a reason which he repeated the properties within the nested class that I'm not seeing?

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• How to develop RPG Damage Formulas?

  - by user127817

  I'm developing a classical 2d RPG (in a similar vein to final fantasy) and I was wondering if anyone had some advice on how to do damage formulas/links to resources/examples? I'll explain my current setup. Hopefully I'm not overdoing it with this question, and I apologize if my questions is too large/broad My Characters stats are composed of the following: enum Stat { HP = 0, MP = 1, SP = 2, Strength = 3, Vitality = 4, Magic = 5, Spirit = 6, Skill = 7, Speed = 8, //Speed/Agility are the same thing Agility = 8, Evasion = 9, MgEvasion = 10, Accuracy = 11, Luck = 12, }; Vitality is basically defense to physical attacks and spirit is defense to magic attacks. All stats have fixed maximums (9999 for HP, 999 for MP/SP and 255 for the rest). With abilities, the maximums can be increased (99999 for HP, 9999 for HP/SP, 999 for the rest) with typical values (at level 100) before/after abilities+equipment+etc will be 8000/20,000 for HP, 800/2000 for SP/MP, 180/350 for other stats Late game Enemy HP will typically be in the lower millions (with a super boss having the maximum of ~12 million). I was wondering how do people actually develop proper damage formulas that scale correctly? For instance, based on this data, using the damage formulas for Final Fantasy X as a base looked very promising. A full reference here http://www.gamefaqs.com/ps2/197344-final-fantasy-x/faqs/31381 but as a quick example: Str = 127, 'Attack' command used, enemy Def = 34. 1. Physical Damage Calculation: Step 1 ------------------------------------- [{(Stat^3 ÷ 32) + 32} x DmCon ÷16] Step 2 ---------------------------------------- [{(127^3 ÷ 32) + 32} x 16 ÷ 16] Step 3 -------------------------------------- [{(2048383 ÷ 32) + 32} x 16 ÷ 16] Step 4 --------------------------------------------------- [{(64011) + 32} x 1] Step 5 -------------------------------------------------------- [{(64043 x 1)}] Step 6 ---------------------------------------------------- Base Damage = 64043 Step 7 ----------------------------------------- [{(Def - 280.4)^2} ÷ 110] + 16 Step 8 ------------------------------------------ [{(34 - 280.4)^2} ÷ 110] + 16 Step 9 ------------------------------------------------- [(-246)^2) ÷ 110] + 16 Step 10 ---------------------------------------------------- [60516 ÷ 110] + 16 Step 11 ------------------------------------------------------------ [550] + 16 Step 12 ---------------------------------------------------------- DefNum = 566 Step 13 ---------------------------------------------- [BaseDmg * DefNum ÷ 730] Step 14 --------------------------------------------------- [64043 * 566 ÷ 730] Step 15 ------------------------------------------------------ [36248338 ÷ 730] Step 16 ------------------------------------------------- Base Damage 2 = 49655 Step 17 ------------ Base Damage 2 * {730 - (Def * 51 - Def^2 ÷ 11) ÷ 10} ÷ 730 Step 18 ---------------------- 49655 * {730 - (34 * 51 - 34^2 ÷ 11) ÷ 10} ÷ 730 Step 19 ------------------------- 49655 * {730 - (1734 - 1156 ÷ 11) ÷ 10} ÷ 730 Step 20 ------------------------------- 49655 * {730 - (1734 - 105) ÷ 10} ÷ 730 Step 21 ------------------------------------- 49655 * {730 - (1629) ÷ 10} ÷ 730 Step 22 --------------------------------------------- 49655 * {730 - 162} ÷ 730 Step 23 ----------------------------------------------------- 49655 * 568 ÷ 730 Step 24 -------------------------------------------------- Final Damage = 38635 I simply modified the dividers to include the attack rating of weapons and the armor rating of armor. Magic Damage is calculated as follows: Mag = 255, Ultima is used, enemy MDef = 1 Step 1 ----------------------------------- [DmCon * ([Stat^2 ÷ 6] + DmCon) ÷ 4] Step 2 ------------------------------------------ [70 * ([255^2 ÷ 6] + 70) ÷ 4] Step 3 ------------------------------------------ [70 * ([65025 ÷ 6] + 70) ÷ 4] Step 4 ------------------------------------------------ [70 * (10837 + 70) ÷ 4] Step 5 ----------------------------------------------------- [70 * (10907) ÷ 4] Step 6 ------------------------------------ Base Damage = 190872 [cut to 99999] Step 7 ---------------------------------------- [{(MDef - 280.4)^2} ÷ 110] + 16 Step 8 ------------------------------------------- [{(1 - 280.4)^2} ÷ 110] + 16 Step 9 ---------------------------------------------- [{(-279.4)^2} ÷ 110] + 16 Step 10 -------------------------------------------------- [(78064) ÷ 110] + 16 Step 11 ------------------------------------------------------------ [709] + 16 Step 12 --------------------------------------------------------- MDefNum = 725 Step 13 --------------------------------------------- [BaseDmg * MDefNum ÷ 730] Step 14 --------------------------------------------------- [99999 * 725 ÷ 730] Step 15 ------------------------------------------------- Base Damage 2 = 99314 Step 16 ---------- Base Damage 2 * {730 - (MDef * 51 - MDef^2 ÷ 11) ÷ 10} ÷ 730 Step 17 ------------------------ 99314 * {730 - (1 * 51 - 1^2 ÷ 11) ÷ 10} ÷ 730 Step 18 ------------------------------ 99314 * {730 - (51 - 1 ÷ 11) ÷ 10} ÷ 730 Step 19 --------------------------------------- 99314 * {730 - (49) ÷ 10} ÷ 730 Step 20 ----------------------------------------------------- 99314 * 725 ÷ 730 Step 21 -------------------------------------------------- Final Damage = 98633 The problem is that the formulas completely fall apart once stats start going above 255. In particular Defense values over 300 or so start generating really strange behavior. High Strength + Defense stats lead to massive negative values for instance. While I might be able to modify the formulas to work correctly for my use case, it'd probably be easier just to use a completely new formula. How do people actually develop damage formulas? I was considering opening excel and trying to build the formula that way (mapping Attack Stats vs. Defense Stats for instance) but I was wondering if there's an easier way? While I can't convey the full game mechanics of my game here, might someone be able to suggest a good starting place for building a damage formula? Thanks

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• Cutting Subscriber Churn with Media Intelligence

  - by Oracle M&E

  There's lots of talk in media and entertainment companies about using "big data".  But it's often hard to see through the hype and understand how big data brings benefits in the real world.  How about being able to predict with 92% accuracy which subscribers intend to cancel their subscription - and put in place a renewal strategy to dramatically reduce that churn?  That's what Belgian media company De Persgroep has achieved with Oracle's Media Intelligence solution.  "One of the areas in which we're able to achieve beautiful results using big data is the churn prediction," De Persgroep's CIO Luc Verbist explains in a new Oracle video.  "Based on all the data that we collect on websites and all your behavior, payment behavior and so on, we're able to make a prediction model, which, with an accuracy of 92 percent, is able to predict that you probably won't renew your newspaper, anymore. So our approach to renewal is completely different to the people in that segment than towards the other people. And this has brought us a lot of value and a lot of customers who didn't stop their newspaper where else they would have done so." De Persgroep is using Oracle's Big Data Appliance, along with software from Oracle partner NGDATA to build up a detailed "DNA profile" of each individual customer, based on every interaction, in real time.  This means that any change in behavior - a drop in content consumption, a late subscription payment, a negative social media comment - is captured.  Applying advanced data modeling techniques automatically converts those raw interactions into data with real business meaning - like that customer's risk of churning. The very same data profile - comprising hundreds if individual dimensions - can simultaneously drive targeted marketing campaigns - informing audience about new content that's most relevant and encouraging them to subscribe.  It can power content recommendations and personalization right in the content sites and apps. And it can link directly into digital advertising networks via platforms like Oracle's BlueKai data management platform (DMP), to drive increased advertising CPMs. Using Oracle's Media Intelligence solution enables this across De Persgroep's business - comprising eight newspapers and 25 magazines published in Belgium and The Netherlands, and digital properties including websites with 6m daily unique visitors, along with TV and radio stations. "The company strategy is in fact a customer-centric strategy, so we want to get a 360-view about our customers, about our prospects. And the big data project helped us to achieve that goal," says Verbist. Using Oracle's Big Data Appliance to underpin the solution created huge savings.   "The selection of the Big Data Appliance was quite easy.  It was very quick to install, very easy to install, as well. And it was far cheaper than building our own Hadoop cluster. So it was in fact a non-brainer," Verbist explains. Applying Media Intelligence approach has yielded incredible results for De Persgroep, including: Improved products - with a new understanding of how readers are consuming print and digital content across the day Improved customer segmentation - driving a 6X improvement in customer prospecting and acquisition when contacting a specific segment Having the project up and running in three months And that has led to competitive benefits for De Persgroep, as Luc Verbist explains: "one of the results we saw since we started using big data is that we're able to increase the gap between we as the market leader, and the second [by] more than 20 percent."

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• C#: A "Dumbed-Down" C++?

  - by James Michael Hare

  I was spending a lovely day this last weekend watching my sons play outside in one of the better weekends we've had here in Saint Louis for quite some time, and whilst watching them and making sure no limbs were broken or eyes poked out with sticks and other various potential injuries, I was perusing (in the correct sense of the word) this month's MSDN magazine to get a sense of the latest VS2010 features in both IDE and in languages. When I got to the back pages, I saw a wonderful article by David S. Platt entitled, "In Praise of Dumbing Down"  (msdn.microsoft.com/en-us/magazine/ee336129.aspx).  The title captivated me and I read it and found myself agreeing with it completely especially as it related to my first post on divorcing C++ as my favorite language. Unfortunately, as Mr. Platt mentions, the term dumbing-down has negative connotations, but is really and truly a good thing.  You are, in essence, taking something that is extremely complex and reducing it to something that is much easier to use and far less error prone.  Adding safeties to power tools and anti-kick mechanisms to chainsaws are in some sense "dumbing them down" to the common user -- but that also makes them safer and more accessible for the common user.  This was exactly my point with C++ and C#.  I did not mean to infer that C++ was not a useful or good language, but that in a very high percentage of cases, is too complex and error prone for the job at hand. Choosing the correct programming language for a job is a lot like choosing any other tool for a task.  For example: if I want to dig a French drain in my lawn, I can attempt to use a huge tractor-like backhoe and the job would be done far quicker than if I would dig it by hand.  I can't deny that the backhoe has the raw power and speed to perform.  But you also cannot deny that my chances of injury or chances of severing utility lines or other resources climb at an exponential rate inverse to the amount of training I may have on that machinery. Is C++ a powerful tool?  Oh yes, and it's great for those tasks where speed and performance are paramount.  But for most of us, it's the wrong tool.  And keep in mind, I say this even though I have 17 years of experience in using it and feel myself highly adept in utilizing its features both in the standard libraries, the STL, and in supplemental libraries such as BOOST.  Which, although greatly help with adding powerful features quickly, do very little to curb the relative dangers of the language. So, you may say, the fault is in the developer, that if the developer had some higher skills or if we only hired C++ experts this would not be an issue.  Now, I will concede there is some truth to this.  Obviously, the higher skilled C++ developers you hire the better the chance they will produce highly performant and error-free code.  However, what good is that to the average developer who cannot afford a full stable of C++ experts? That's my point with C#:  It's like a kinder, gentler C++.  It gives you nearly the same speed, and in many ways even more power than C++, and it gives you a much softer cushion for novices to fall against if they code less-than-optimally.  A bug is a bug, of course, in any language, but C# does a good job of hiding and taking on the task of handling almost all of the resource issues that make C++ so tricky.  For my money, C# is much more maintainable, more feature-rich, second only slightly in performance, faster to market, and -- last but not least -- safer and easier to use.  That's why, where I work, I much prefer to see the developers moving to C#.  The quantity of bugs is much lower, and we don't need to hire "experts" to achieve the same results since the language itself handles those resource pitfalls so prevalent in poorly written C++ code.  C++ will still have its place in the world, and I'm sure I'll still use it now and again where it is truly the correct tool for the job, but for nearly every other project C# is a wonderfully "dumbed-down" version of C++ -- in the very best sense -- and to me, that's the smart choice.

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• Launch 7:Windows Phone 7 Style Live Tiles On Android Mobiles

  - by Gopinath

  Android is a great mobile OS but one thought that lingers in the mind of few Android owners is: Am I using a cheap iPhone? This is valid thought for many low end Android users as their phones runs sluggish and the user interface of Android looks like an imitation of iOS. When it comes to Windows Phone 7 users, even though their operating system features are not as great as iPhone/Android but it has its unique user interface; Windows Phone 7 user interface is a very intuitive and fresh, it’s constantly updating Live Tiles show all the required information on the home screen. Android has best mobile operating system features except UI and Windows Phone 7 has excellent user interface. How about porting Windows Phone 7 Tiles interface on an Android? That should be great. Launch 7 app brings the best of Windows Phone 7 look and feel to Android OS. Once the Launcher 7 app is installed and activated, it brings Live Tiles or constantly updating controls that show information on Android home screen. Apart from simple and smooth tiles, there are handful of customization options provided. Users can change colour of the tiles, add new tiles, enable/disable transitions. The reviews on Android Market are on the positive side with 4.4 stars by 10,000 + reviewers. Here are few user reviews 1. Does what it says. only issue for me is that the app drawer doesn’t rotate. And I would like the UI to rotate when my KB is opened. HTC desire z – Jonathan 2. Works great on atrix.Kudos to developers. Awesome. Though needs: Better notification bar More stock images of tiles Better fitting of widgets on tiles – Manny 3. Looks really good like it much more than I thought I would runs real smooth running royal ginger 2.1 – Jay 4. Omg amazing i am definetly keeping it as my default best of android and windows – Devon 5. Man! An update every week! Very very responsive developer! – Andrew You can read more reviews on Android Market here.  There is no doubt that this application is receiving rave reviews. After scanning a while through the reviews, few complaints throw light on the negative side: Battery drains a bit faster & Low end mobile run a bit sluggish. The application is available in two versions – an ad supported free version and $1.41 ad free version. Download Launcher 7 from Android Market This article titled,Launch 7:Windows Phone 7 Style Live Tiles On Android Mobiles, was originally published at Tech Dreams. Grab our rss feed or fan us on Facebook to get updates from us.

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• 13 Things From the Oracle Social Summit You Should Know

  - by Mike Stiles

  Oracle held its first annual Oracle Social Summit, “The School for the Socially Gifted,” this past week in Las Vegas.  If anyone came to the event uncertain as to why Oracle has such an interest in social, and what its plans for social are, they left with an entirely new vision of where social is headed, and why.For those unable to attend, I was able to keep my MacBook charged just long enough to capture some of the more pertinent takeaways.1. The social enterprise is inevitable.  Social technology is disrupting the hierarchies of big companies.  It’s a revolution in corporate structures, just as it has been in various governments.  It’s not crazy to ask yourself if your CEO is the next Mubarak.  (David Kilpatrick Author of “The Facebook Effect” and founder of the Techonomy Conference) 2. The social enterprise represents collaboration on steroids.  It’s tapping into the power of your people, as opposed to keeping them “in their place.”  3. 1 in every 7 humans on earth is an active Facebook user.  75% have posted a negative comment after a poor customer experience.  The average user will inform 53 people of a bad experience.4. Checking social media is the 2nd biggest use of phones now.  Reading posts from brands is 4th.5. 70% of marketers have little or no understanding of the social conversations happening around their brand.6. Advertising, when done well, is content we care about, preferably informed by those we trust.7. Acquiring low-quality fans through gimmicks, or focusing purely on fan acquisition is a mistake.  And relying purely on organic distribution is a mistake.  (John Yi, Head of Marketing Partnerships – Facebook)8. Using all this newfound data and insight serves to positively affect the customer experience.  It allows organizations to now leverage the investments they’ve made in social up to now.9. Social is not a marketing utopia where everything is free.  It’s pay to play.  The paid component is about driving attention.  10. We are only in the infancy of ad-targeting opportunities in social.  There’s an evolution underway from interest-based targeting to action-based targeting.11. There’s actually very little overlap of the people following you on different social platforms.  Don’t assume it’s the same audience on each.12. People who can create content and who also have an understanding of what drives that content are growing increasingly valuable.13. Oracle Social’s future is enterprise SRM, integrated across marketing, selling, service, HR and every other corner of the organization.And in case you thought those were the only gems to come out of the summit, you may want to keep an eye out for Tuesday’s Social Spotlight, ever so aptly titled “13 More Things from the Oracle Social Summit You Should Know.”

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• How can I draw an arrow at the edge of the screen pointing to an object that is off screen?

  - by Adam Henderson

  I am wishing to do what is described in this topic: http://www.allegro.cc/forums/print-thread/283220 I have attempted a variety of the methods mentioned here. First I tried to use the method described by Carrus85: Just take the ratio of the two triangle hypontenuses (doesn't matter which triagle you use for the other, I suggest point 1 and point 2 as the distance you calculate). This will give you the aspect ratio percentage of the triangle in the corner from the larger triangle. Then you simply multiply deltax by that value to get the x-coordinate offset, and deltay by that value to get the y-coordinate offset. But I could not find a way to calculate how far the object is away from the edge of the screen. I then tried using ray casting (which I have never done before) suggested by 23yrold3yrold: Fire a ray from the center of the screen to the offscreen object. Calculate where on the rectangle the ray intersects. There's your coordinates. I first calculated the hypotenuse of the triangle formed by the difference in x and y positions of the two points. I used this to create a unit vector along that line. I looped through that vector until either the x coordinate or the y coordinate was off the screen. The two current x and y values then form the x and y of the arrow. Here is the code for my ray casting method (written in C++ and Allegro 5) void renderArrows(Object* i) { float x1 = i->getX() + (i->getWidth() / 2); float y1 = i->getY() + (i->getHeight() / 2); float x2 = screenCentreX; float y2 = ScreenCentreY; float dx = x2 - x1; float dy = y2 - y1; float hypotSquared = (dx * dx) + (dy * dy); float hypot = sqrt(hypotSquared); float unitX = dx / hypot; float unitY = dy / hypot; float rayX = x2 - view->getViewportX(); float rayY = y2 - view->getViewportY(); float arrowX = 0; float arrowY = 0; bool posFound = false; while(posFound == false) { rayX += unitX; rayY += unitY; if(rayX <= 0 || rayX >= screenWidth || rayY <= 0 || rayY >= screenHeight) { arrowX = rayX; arrowY = rayY; posFound = true; } } al_draw_bitmap(sprite, arrowX - spriteWidth, arrowY - spriteHeight, 0); } This was relatively successful. Arrows are displayed in the bottom right section of the screen when objects are located above and left of the screen as if the locations of the where the arrows are drawn have been rotated 180 degrees around the center of the screen. I assumed this was due to the fact that when I was calculating the hypotenuse of the triangle, it would always be positive regardless of whether or not the difference in x or difference in y is negative. Thinking about it, ray casting does not seem like a good way of solving the problem (due to the fact that it involves using sqrt() and a large for loop). Any help finding a suitable solution would be greatly appreciated, Thanks Adam

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• Guest blog: A Closer Look at Oracle Price Analytics by Will Hutchinson

  - by Takin Babaei

  Overview:  Price Analytics helps companies understand how much of each sale goes into discounts, special terms, and allowances. This visibility lets sales management see the panoply of discounts and start seeing whether each discount drives desired behavior. In Price Analytics monitors parts of the quote-to-order process, tracking quotes, including the whole price waterfall and seeing which result in orders. The “price waterfall” shows all discounts between list price and “pocket price”. Pocket price is the final price the vendor puts in its pocket after all discounts are taken. The value proposition: Based on benchmarks from leading consultancies and companies I have talked to, where they have studied the effects of discounting and started enforcing what many of them call “discount discipline”, they find they can increase the pocket price by 0.8-3%. Yes, in today’s zero or negative inflation environment, one can, through better monitoring of discounts, collect what amounts to a price rise of a few percent. We are not talking about selling more product, merely about collecting a higher pocket price without decreasing quantities sold. Higher prices fall straight to the bottom line. The best reference I have ever found for understanding this phenomenon comes from an article from the September-October 1992 issue of Harvard Business Review called “Managing Price, Gaining Profit” by Michael Marn and Robert Rosiello of McKinsey & Co. They describe the outsized impact price management has on bottom line performance compared to selling more product or cutting variable or fixed costs. Price Analytics manages what Marn and Rosiello call “transaction pricing”, namely the prices of a given transaction, as opposed to what is on the price list or pricing according to the value received. They make the point that if the vendor does not manage the price waterfall, customers will, to the vendor’s detriment. It also discusses its findings that in companies it studied, there was no correlation between discount levels and any indication of customer value. I urge you to read this article. What Price Analytics does: Price analytics looks at quotes the company issues and tracks them until either the quote is accepted or rejected or it expires. There are prebuilt adapters for EBS and Siebel as well as a universal adapter. The target audience includes pricing analysts, product managers, sales managers, and VP’s of sales, marketing, finance, and sales operations. It tracks how effective discounts have been, the win rate on quotes, how well pricing policies have been followed, customer and product profitability, and customer performance against commitments. It has the concept of price waterfall, the deal lifecycle, and price segmentation built into the product. These help product and sales managers understand their pricing and its effectiveness on driving revenue and profit. They also help understand how terms are adhered to during negotiations. They also help people understand what segments exist and how well they are adhered to. To help your company increase its profits and revenues, I urge you to look at this product. If you have questions, please contact me. Will HutchinsonMaster Principal Sales Consultant – Analytics, Oracle Corp. Will Hutchinson has worked in the business intelligence and data warehousing for over 25 years. He started building data warehouses in 1986 at Metaphor, advancing to running Metaphor UK’s sales consulting area. He also worked in A.T. Kearney’s business intelligence practice for over four years, running projects and providing training to new consultants in the IT practice. He also worked at Informatica and then Siebel, before coming to Oracle with the Siebel acquisition. He became Master Principal Sales Consultant in 2009. He has worked on developing ROI and TCO models for business intelligence for over ten years. Mr. Hutchinson has a BS degree in Chemical Engineering from Princeton University and an MBA in Finance from the University of Chicago.

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• Organization &amp; Architecture UNISA Studies &ndash; Chap 6

  - by MarkPearl

  Learning Outcomes Discuss the physical characteristics of magnetic disks Describe how data is organized and accessed on a magnetic disk Discuss the parameters that play a role in the performance of magnetic disks Describe different optical memory devices Magnetic Disk The way data is stored on and retried from magnetic disks Data is recorded on and later retrieved form the disk via a conducting coil named the head (in many systems there are two heads) The writ mechanism exploits the fact that electricity flowing through a coil produces a magnetic field. Electric pulses are sent to the write head, and the resulting magnetic patterns are recorded on the surface below with different patterns for positive and negative currents The physical characteristics of a magnetic disk   Summarize from book   The factors that play a role in the performance of a disk Seek time – the time it takes to position the head at the track Rotational delay / latency – the time it takes for the beginning of the sector to reach the head Access time – the sum of the seek time and rotational delay Transfer time – the time it takes to transfer data RAID The rate of improvement in secondary storage performance has been considerably less than the rate for processors and main memory. Thus secondary storage has become a bit of a bottleneck. RAID works on the concept that if one disk can be pushed so far, additional gains in performance are to be had by using multiple parallel components. Points to note about RAID… RAID is a set of physical disk drives viewed by the operating system as a single logical drive Data is distributed across the physical drives of an array in a scheme known as striping Redundant disk capacity is used to store parity information, which guarantees data recoverability in case of a disk failure (not supported by RAID 0 or RAID 1) Interesting to note that the increase in the number of drives, increases the probability of failure. To compensate for this decreased reliability RAID makes use of stored parity information that enables the recovery of data lost due to a disk failure.   The RAID scheme consists of 7 levels…   Category Level Description Disks Required Data Availability Large I/O Data Transfer Capacity Small I/O Request Rate Striping 0 Non Redundant N Lower than single disk Very high Very high for both read and write Mirroring 1 Mirrored 2N Higher than RAID 2 – 5 but lower than RAID 6 Higher than single disk Up to twice that of a signle disk for read Parallel Access 2 Redundant via Hamming Code N + m Much higher than single disk Highest of all listed alternatives Approximately twice that of a single disk Parallel Access 3 Bit interleaved parity N + 1 Much higher than single disk Highest of all listed alternatives Approximately twice that of a single disk Independent Access 4 Block interleaved parity N + 1 Much higher than single disk Similar to RAID 0 for read, significantly lower than single disk for write Similar to RAID 0 for read, significantly lower than single disk for write Independent Access 5 Block interleaved parity N + 1 Much higher than single disk Similar to RAID 0 for read, lower than single disk for write Similar to RAID 0 for read, generally  lower than single disk for write Independent Access 6 Block interleaved parity N + 2 Highest of all listed alternatives Similar to RAID 0 for read; lower than RAID 5 for write Similar to RAID 0 for read, significantly lower than RAID 5  for write   Read page 215 – 221 for detailed explanation on RAID levels Optical Memory There are a variety of optical-disk systems available. Read through the table on page 222 – 223 Some of the devices include… CD CD-ROM CD-R CD-RW DVD DVD-R DVD-RW Blue-Ray DVD Magnetic Tape Most modern systems use serial recording – data is lade out as a sequence of bits along each track. The typical recording used in serial is referred to as serpentine recording. In this technique when data is being recorded, the first set of bits is recorded along the whole length of the tape. When the end of the tape is reached the heads are repostioned to record a new track, and the tape is again recorded on its whole length, this time in the opposite direction. That process continued back and forth until the tape is full. To increase speed, the read-write head is capable of reading and writing a number of adjacent tracks simultaneously. Data is still recorded serially along individual tracks, but blocks in sequence are stored on adjacent tracks as suggested. A tape drive is a sequential access device. Magnetic tape was the first kind of secondary memory. It is still widely used as the lowest-cost, slowest speed member of the memory hierarchy.

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• Google Fetch issue

  - by Karen

  When I do a Google fetch on any of my webpages the results are all the same (below). I'm not a programmer but I'm pretty sure this is not correct. Out of all the fetches I have done only one was different and the content length was 6x below and showed meta tags etc. Maybe this explains other issues I've been having with the site: a drop in indexed pages. Meta tag analyzer says I have no title tag, meta tags or description even though I do it on all pages. I had an SEO team working on the site and they were stumped by why pages were not getting indexed. So they figure it was some type of code error. Are they right? HTTP/1.1 200 OK Cache-Control: private Content-Type: text/html; charset=utf-8 Content-Encoding: gzip Vary: Accept-Encoding Server: Microsoft-IIS/7.5 X-AspNet-Version: 4.0.30319 X-Powered-By: ASP.NET Date: Thu, 11 Oct 2012 11:45:41 GMT Content-Length: 1054 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title></title> <script type="text/javascript"> function getCookie(cookieName) { if (document.cookie.length > 0) { cookieStart = document.cookie.indexOf(cookieName + "="); if (cookieStart != -1) { cookieStart = cookieStart + cookieName.length + 1; cookieEnd = document.cookie.indexOf(";", cookieStart); if (cookieEnd == -1) cookieEnd = document.cookie.length; return unescape(document.cookie.substring(cookieStart, cookieEnd)); } } return ""; } function setTimezone() { var rightNow = new Date(); var jan1 = new Date(rightNow.getFullYear(), 0, 1, 0, 0, 0, 0); // jan 1st var june1 = new Date(rightNow.getFullYear(), 6, 1, 0, 0, 0, 0); // june 1st var temp = jan1.toGMTString(); var jan2 = new Date(temp.substring(0, temp.lastIndexOf(" ") - 1)); temp = june1.toGMTString(); var june2 = new Date(temp.substring(0, temp.lastIndexOf(" ") - 1)); var std_time_offset = (jan1 - jan2) / (1000 * 60 * 60); var daylight_time_offset = (june1 - june2) / (1000 * 60 * 60); var dst; if (std_time_offset == daylight_time_offset) { dst = "0"; // daylight savings time is NOT observed } else { // positive is southern, negative is northern hemisphere var hemisphere = std_time_offset - daylight_time_offset; if (hemisphere >= 0) std_time_offset = daylight_time_offset; dst = "1"; // daylight savings time is observed } var exdate = new Date(); var expiredays = 1; exdate.setDate(exdate.getDate() + expiredays); document.cookie = "TimeZoneOffset=" + std_time_offset + ";"; document.cookie = "Dst=" + dst + ";expires=" + exdate.toUTCString(); } function checkCookie() { var timeOffset = getCookie("TimeZoneOffset"); var dst = getCookie("Dst"); if (!timeOffset || !dst) { setTimezone(); window.location.reload(); } } </script> </head> <body onload="checkCookie()"> </body> </html>

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• Circle-Line Collision Detection Problem

  - by jazzdawg

  I am currently developing a breakout clone and I have hit a roadblock in getting collision detection between a ball (circle) and a brick (convex polygon) working correctly. I am using a Circle-Line collision detection test where each line represents and edge on the convex polygon brick. For the majority of the time the Circle-Line test works properly and the points of collision are resolved correctly. Collision detection working correctly. However, occasionally my collision detection code returns false due to a negative discriminant when the ball is actually intersecting the brick. Collision detection failing. I am aware of the inefficiency with this method and I am using axis aligned bounding boxes to cut down on the number of bricks tested. My main concern is if there are any mathematical bugs in my code below. /* * from and to are points at the start and end of the convex polygons edge. * This function is called for every edge in the convex polygon until a * collision is detected. */ bool circleLineCollision(Vec2f from, Vec2f to) { Vec2f lFrom, lTo, lLine; Vec2f line, normal; Vec2f intersectPt1, intersectPt2; float a, b, c, disc, sqrt_disc, u, v, nn, vn; bool one = false, two = false; // set line vectors lFrom = from - ball.circle.centre; // localised lTo = to - ball.circle.centre; // localised lLine = lFrom - lTo; // localised line = from - to; // calculate a, b & c values a = lLine.dot(lLine); b = 2 * (lLine.dot(lFrom)); c = (lFrom.dot(lFrom)) - (ball.circle.radius * ball.circle.radius); // discriminant disc = (b * b) - (4 * a * c); if (disc < 0.0f) { // no intersections return false; } else if (disc == 0.0f) { // one intersection u = -b / (2 * a); intersectPt1 = from + (lLine.scale(u)); one = pointOnLine(intersectPt1, from, to); if (!one) return false; return true; } else { // two intersections sqrt_disc = sqrt(disc); u = (-b + sqrt_disc) / (2 * a); v = (-b - sqrt_disc) / (2 * a); intersectPt1 = from + (lLine.scale(u)); intersectPt2 = from + (lLine.scale(v)); one = pointOnLine(intersectPt1, from, to); two = pointOnLine(intersectPt2, from, to); if (!one && !two) return false; return true; } } bool pointOnLine(Vec2f p, Vec2f from, Vec2f to) { if (p.x >= min(from.x, to.x) && p.x <= max(from.x, to.x) && p.y >= min(from.y, to.y) && p.y <= max(from.y, to.y)) return true; return false; }

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