Search Results

Search found 1725 results on 69 pages for 'equation solving'.

Page 16/69 | < Previous Page | 12 13 14 15 16 17 18 19 20 21 22 23  | Next Page >

  • iptables change destination address base on result from mysql

    - by user1812225
    I need to change destination address of tcp/ip packets based on result of execution mysql query... SELECT `score` FROM `reputation` WHERE `ip` = packet.source_ip if (score < a) then packet.destination_ip = ... else packet.destination_ip = ... What ways of solving this problem do you see? Thanks. P.S. this is important that destination host knows REAL ip address where packet came from, not IP address of firewall.

    Read the article

  • APress Deal of the Day 20/August/2014 - Node.js Recipes

    - by TATWORTH
    Originally posted on: http://geekswithblogs.net/TATWORTH/archive/2014/08/20/apress-deal-of-the-day-20august2014---node.js-recipes.aspxToday’s $10 Deal of the Day from APress at http://www.apress.com/9781430260585 is Node.js Recipes. “Node.js Recipes is your one-stop reference for solving Node.js problems. Filled with useful recipes that follow a problem/solution format, you can look up recipes for many situations that you may come across in your day-to-day server-side development. ”

    Read the article

  • User-driven applications

    User-driven applications are the programs in which full control is given to the users. Designers of such programs are responsible only for developing an instrument for solving some task, but they do not enforce users to work with this instrument according with a predefined scenario.

    Read the article

  • How much is a subscriber worth?

    - by Tom Lewin
    This year at Red Gate, we’ve started providing a way to back up SQL Azure databases and Azure storage. We decided to sell this as a service, instead of a product, which means customers only pay for what they use. Unfortunately for us, it makes figuring out revenue much trickier. With a product like SQL Compare, a customer pays for it, and it’s theirs for good. Sure, we offer support and upgrades, but, fundamentally, the sale is a simple, upfront transaction: we’ve made this product, you need this product, we swap product for money and everyone is happy. With software as a service, it isn’t that easy. The money and product don’t change hands up front. Instead, we provide a service in exchange for a recurring fee. We know someone buying SQL Compare will pay us $X, but we don’t know how long service customers will stay with us, or how much they will spend. How do we find this out? We use lifetime value analysis. What is lifetime value? Lifetime value, or LTV, is how much a customer is worth to the business. For Entrepreneurs has a brilliant write up that we followed to conduct our analysis. Basically, it all boils down to this equation: LTV = ARPU x ALC To make it a bit less of an alphabet-soup and a bit more understandable, we can write it out in full: The lifetime value of a customer equals the average revenue per customer per month, times the average time a customer spends with the service Simple, right? A customer is worth the average spend times the average stay. If customers pay on average $50/month, and stay on average for ten months, then a new customer will, on average, bring in $500 over the time they are a customer! Average spend is easy to work out; it’s revenue divided by customers. The problem comes when we realise that we don’t know exactly how long a customer will stay with us. How can we figure out the average lifetime of a customer, if we only have six months’ worth of data? The answer lies in the fact that: Average Lifetime of a Customer = 1 / Churn Rate The churn rate is the percentage of customers that cancel in a month. If half of your customers cancel each month, then your average customer lifetime is two months. The problem we faced was that we didn’t have enough data to make an estimate of one month’s cancellations reliable (because barely anybody cancels)! To deal with this data problem, we can take data from the last three months instead. This means we have more data to play with. We can still use the equation above, we just need to multiply the final result by three (as we worked out how many three month periods customers stay for, and we want our answer to be in months). Now these estimates are likely to be fairly unreliable; when there’s not a lot of data it pays to be cautious with inference. That said, the numbers we have look fairly consistent, and it’s super easy to revise our estimates when new data comes in. At the very least, these numbers give us a vague idea of whether a subscription business is viable. As far as Cloud Services goes, the business looks very viable indeed, and the low cancellation rates are much more than just data points in LTV equations; they show that the product is working out great for our customers, which is exactly what we’re looking for!

    Read the article

  • Efficient Multiple Linear Regression in C# / .Net

    - by mrnye
    Does anyone know of an efficient way to do multiple linear regression in C#, where the number of simultaneous equations may be in the 1000's (with 3 or 4 different inputs). After reading this article on multiple linear regression I tried implementing it with a matrix equation: Matrix y = new Matrix( new double[,]{{745}, {895}, {442}, {440}, {1598}}); Matrix x = new Matrix( new double[,]{{1, 36, 66}, {1, 37, 68}, {1, 47, 64}, {1, 32, 53}, {1, 1, 101}}); Matrix b = (x.Transpose() * x).Inverse() * x.Transpose() * y; for (int i = 0; i < b.Rows; i++) { Trace.WriteLine("INFO: " + b[i, 0].ToDouble()); } However it does not scale well to the scale of 1000's of equations due to the matrix inversion operation. I can call the R language and use that, however I was hoping there would be a pure .Net solution which will scale to these large sets. Any suggestions? EDIT #1: I have settled using R for the time being. By using statconn (downloaded here) I have found it to be both fast & relatively easy to use this method. I.e. here is a small code snippet, it really isn't much code at all to use the R statconn library (note: this is not all the code!). _StatConn.EvaluateNoReturn(string.Format("output <- lm({0})", equation)); object intercept = _StatConn.Evaluate("coefficients(output)['(Intercept)']"); parameters[0] = (double)intercept; for (int i = 0; i < xColCount; i++) { object parameter = _StatConn.Evaluate(string.Format("coefficients(output)['x{0}']", i)); parameters[i + 1] = (double)parameter; }

    Read the article

  • Accurate least-squares fit algorithm needed

    - by ggkmath
    I've experimented with the two ways of implementing a least-squares fit (LSF) algorithm shown here. The first code is simply the textbook approach, as described by Wolfram's page on LSF. The second code re-arranges the equation to minimize machine errors. Both codes produce similar results for my data. I compared these results with Matlab's p=polyfit(x,y,1) function, using correlation coefficients to measure the "goodness" of fit and compare each of the 3 routines. I observed that while all 3 methods produced good results, at least for my data, Matlab's routine had the best fit (the other 2 routines had similar results to each other). Matlab's p=polyfit(x,y,1) function uses a Vandermonde matrix, V (n x 2 matrix) and QR factorization to solve the least-squares problem. In Matlab code, it looks like: V = [x1,1; x2,1; x3,1; ... xn,1] % this line is pseudo-code [Q,R] = qr(V,0); p = R\(Q'*y); % performs same as p = V\y I'm not a mathematician, so I don't understand why it would be more accurate. Although the difference is slight, in my case I need to obtain the slope from the LSF and multiply it by a large number, so any improvement in accuracy shows up in my results. For reasons I can't get into, I cannot use Matlab's routine in my work. So, I'm wondering if anyone has a more accurate equation-based approach recommendation I could use that is an improvement over the above two approaches, in terms of rounding errors/machine accuracy/etc. Any comments appreciated! thanks in advance.

    Read the article

  • Attempting my first fortran 95 program, to solve quadratic eqn. Getting weird errors.

    - by Damon
    So, I'm attempting my first program in Fortran, trying to solve quadratic eqn. I have double and triple checked my code and don't see anything wrong. I keep getting "Invalid character in name at (1)" and "Unclassifiable statement at (1)" at various locations. Any help would be greatly appreciated... ! This program solves quadratic equations ! of the form ax^2 + bx + c = 0. ! Record: ! Name: Date: Notes: ! Damon Robles 4/3/10 Original Code PROGRAM quad_solv IMPLICIT NONE ! Variables REAL :: a, b, c REAL :: discrim, root1, root2, COMPLEX :: comp1, comp2 CHARACTER(len=1) :: correct ! Prompt user for coefficients. WRITE(*,*) "This program solves quadratic equations " WRITE(*,*) "of the form ax^2 + bx + c = 0. " WRITE(*,*) "Please enter the coefficients a, b, and " WRITE(*,*) "c, separated by commas:" READ(*,*) a, b, c WRITE(*,*) "Is this correct: a = ", a, " b = ", b WRITE(*,*) " c = ", c, " [Y/N]? " READ(*,*) correct IF correct = N STOP IF correct = Y THEN ! Definition discrim = b**2 - 4*a*c ! Calculations IF discrim > 0 THEN root1 = (-b + sqrt(discrim))/(2*a) root2 = (-b - sqrt(discrim))/(2*a) WRITE(*,*) "This equation has two real roots. " WRITE(*,*) "x1 = ", root1 WRITE(*,*) "x2 = ", root2 IF discrim = 0 THEN root1 = -b/(2*a) WRITE(*,*) "This equation has a double root. " WRITE(*,*) "x1 = ", root1 IF discrim < 0 THEN comp1 = (-b + sqrt(discrim))/(2*a) comp2 = (-b - sqrt(discrim))/(2*a) WRITE(*,*) "x1 = ", comp1 WRITE(*,*) "x2 = ", comp2 PROGRAM END quad_solv Thanks in advance!

    Read the article

  • LaTex, align alignment characters between align blocks

    - by ccook
    I would like to align two alignment characters between two align blocks so that I can have some text in the middle of a derivation with equations maintaining the horizontal alignment. For example the following excerpt of latex using align \begin{align*} \frac{\delta \phi}{\delta x_1} = {} &\frac{9}{8}\frac{\delta_1\phi}{\delta_1x_1}-\frac{1}{8}\frac{\delta_3\phi}{\delta_3x_1} \\ & \frac{9}{8}\frac{1}{h_1}\left[\phi(x_1+h_1/2)-\phi(x_i-h_1/2)\right]-\frac{1}{8}\frac{1}{3h_1}\left[\phi(x_i+3h_1/2)-\phi(x_1-3h_1/2)\right] \end{align*} some text in the middle \begin{align*} & \frac{9}{8}\frac{1}{h_1}\left[\phi(x_1+h_1/2)-\phi(x_i-h_1/2)\right]-\frac{1}{8}\frac{1}{3h_1}\left[\phi(x_i+3h_1/2)-\phi(x_1-3h_1/2)\right] \end{align*} Ideally I would like the left of the equation in the second block to line up with that of the second equation in the first block. I could do a workaround by not having text in the middle, however, I would like this functionality. EDIT I would like to have a good amount of text between. Say three to four lines that line up as normal paragraphs. Adding text in the alignment block is the workaround I poorly alluded to.

    Read the article

  • Scheme Infix to Postfix

    - by Cody
    Let me establish that this is part of a class assignment, so I'm definitely not looking for a complete code answer. Essentially we need to write a converter in Scheme that takes a list representing a mathematical equation in infix format and then output a list with the equation in postfix format. We've been provided with the algorithm to do so, simple enough. The issue is that there is a restriction against using any of the available imperative language features. I can't figure out how to do this in a purely functional manner. This is our fist introduction to functional programming in my program. I know I'm going to be using recursion to iterate over the list of items in the infix expression like such. (define (itp ifExpr) ( ; do some processing using cond statement (itp (cdr ifExpr)) )) I have all of the processing implemented (at least as best I can without knowing how to do the rest) but the algorithm I'm using to implement this requires that operators be pushed onto a stack and used later. My question is how do I implement a stack in this function that is available to all of the recursive calls as well?

    Read the article

  • Python OOP and lists

    - by Mikk
    Hi, I'm new to Python and it's OOP stuff and can't get it to work. Here's my code: class Tree: root = None; data = []; def __init__(self, equation): self.root = equation; def appendLeft(self, data): self.data.insert(0, data); def appendRight(self, data): self.data.append(data); def calculateLeft(self): result = []; for item in (self.getLeft()): if (type(item) == type(self)): data = item.calculateLeft(); else: data = item; result.append(item); return result; def getLeft(self): return self.data; def getRight(self): data = self.data; data.reverse(); return data; tree2 = Tree("*"); tree2.appendRight(44); tree2.appendLeft(20); tree = Tree("+"); tree.appendRight(4); tree.appendLeft(10); tree.appendLeft(tree2); print(tree.calculateLeft()); It looks like tree2 and tree are sharing list "data"? At the moment I'd like it to output something like [[20,44], 10, 4], but when I tree.appendLeft(tree2) I get RuntimeError: maximum recursion depth exceeded, and when i even won't appendLeft(tree2) it outputs [10, 20, 44, 4] (!!!). What am I missing here? I'm using Portable Python 3.0.1. Thank you

    Read the article

  • How to determine Scale of Line Graph based on Pixels/Height?

    - by Dexter
    I have a problem due to my terrible math abilities, that I cannot figure out how to scale a graph based on the maximum and minimum values so that the whole graph will fit onto the graph-area (400x420) without parts of it being off the screen (based on a given equation by user). Let's say I have this code, and it automatically draws squares and then the line graph based on these values. What is the formula (what do I multiply) to scale it so that it fits into the small graphing area? vector<int> m_x; vector<int> m_y; // gets automatically filled by user equation or values int HeightInPixels = 420;// Graphing area size!! int WidthInPixels = 400; int best_max_y = GetMaxOfVector(m_y); int best_min_y = GetMinOfVector(m_y); m_row = 0; m_col = 0; y_magnitude = (HeightInPixels/(best_max_y+best_min_y)); // probably won't work magnitude = (WidthInPixels/(int)m_x.size()); m_col = m_row = best_max_y; // number of vertical/horizontal lines to draw ////x_magnitude = (WidthInPixels/(int)m_x.size())/2; Doesn't work well ////y_magnitude = (HeightInPixels/(int)m_y.size())/2; Doesn't work well ready = true; // we have values, graph it Invalidate(); // uses WM_PAINT

    Read the article

  • Formulae for U and V buffer offset

    - by Abhi
    Hi all ! What should be the buffer offset value for U & V in YUV444 format type? Like for an example if i am using YV12 format the value is as follows: ppData.inputIDMAChannel.UBufOffset = iInputHeight * iInputWidth + (iInputHeight * iInputWidth)/4; ppData.inputIDMAChannel.VBufOffset = iInputHeight * iInputWidth; iInputHeight = 160 & iInputWidth = 112 ppdata is an object for the following structure: typedef struct ppConfigDataStruct { //--------------------------------------------------------------- // General controls //--------------------------------------------------------------- UINT8 IntType; // FIRSTMODULE_INTERRUPT: the interrupt will be // rised once the first sub-module finished its job. // FRAME_INTERRUPT: the interrput will be rised // after all sub-modules finished their jobs. //--------------------------------------------------------------- // Format controls //--------------------------------------------------------------- // For input idmaChannel inputIDMAChannel; BOOL bCombineEnable; idmaChannel inputcombIDMAChannel; UINT8 inputcombAlpha; UINT32 inputcombColorkey; icAlphaType alphaType; // For output idmaChannel outputIDMAChannel; CSCEQUATION CSCEquation; // Selects R2Y or Y2R CSC Equation icCSCCoeffs CSCCoeffs; // Selects R2Y or Y2R CSC Equation icFlipRot FlipRot; // Flip/Rotate controls for VF BOOL allowNopPP; // flag to indicate we need a NOP PP processing }*pPpConfigData, ppConfigData; and idmaChannel structure is as follows: typedef struct idmaChannelStruct { icFormat FrameFormat; // YUV or RGB icFrameSize FrameSize; // frame size UINT32 LineStride;// stride in bytes icPixelFormat PixelFormat;// Input frame RGB format, set NULL // to use standard settings. icDataWidth DataWidth;// Bits per pixel for RGB format UINT32 UBufOffset;// offset of U buffer from Y buffer start address // ignored if non-planar image format UINT32 VBufOffset;// offset of U buffer from Y buffer start address // ignored if non-planar image format } idmaChannel, *pIdmaChannel; I want the formulae for ppData.inputIDMAChannel.UBufOffset & ppData.inputIDMAChannel.VBufOffset for YUV444 Thanks in advance

    Read the article

  • SQL Database Schema Design For Large 3 Billion Relationship Database.

    - by K-Bell
    Get your geek on. Can you solve this? I am designing a products database for SQL Server 2008 R2 Ed. (not Enterprise Ed.) that will be used to store custom product configurations for over 30,000 distinct products. The database will have up to 500 users at a time. Here is the design problem… Each Product has a collection of Parts (up to 50 parts per product). So if I have 30,000 Products and each of them can have up to 50 Parts, that’s 1.5 million distinct Product-to-Part relationships …or as an equation… 30,000 (Products) X 50 (Parts) = 1.5 million Product-to-Parts records. …and If… Each Part can have up to 2000 finish options (A finish is a paint color). NOTE: Only one finish will be selected by a user at run-time. The 2000 finish options I need to store are the allowed options for a specific part on a specific product. So if I have 1.5 million distinct product-to-part relationships/records and each of those parts can have up to 2,000 finishes that is 3 billion allowable product-to-part-to finish relationships/records …or as an equation… 1.5 million (Parts) x 2,000 (Finishes) = 3 Billion Product-to-Part-to-Finishes records. How can I design this database so that I can execute fast and efficient queries for a specific product and return its list of Parts and all the allowable Finishes for each part without 3 Billion Product-to-Part-to-Finish records? Read time is more important then write time. Please post your thoughts/suggestions if you have experience with large databases. Thanks!

    Read the article

  • Pandoc: Output two sumation signs in equal height in Word 2010

    - by Andy
    I need to output some complex equations in Word 2010 (docx). To do so I write most of the equations in tex and use pandoc to translate them as Word formulas. However I have a problem with the following tex equation: \sum_{m=1}^\infty\sum_{n=1}^\infty In Word the resulting two summation signs are not of the same size but the latter is smaler than the first one. Is there any workaround to solve this? I would deeply appreciate any help. Thank you Andy

    Read the article

  • What happens when the server that the Remote Desktop Connection Broker goes down?

    - by Frank Owen
    I would like to setup the Remote Desktop Connection Broker to allow better load balancing of the two terminal servers we have as well as allowing the user to re-establish to the correct server if they get disconnected. My worry is, if I set this up and the server this service is running goes down, does the terminal server stop accepting connections or will they just lose the benefit of having RDCB turned on? I don't want to add another point of failure in this equation unless I have to.

    Read the article

  • If my Remote Desktop Connection Broker server goes down, can users still access my two Terminal Servers?

    - by Frank Owen
    I would like to setup the Remote Desktop Connection Broker to allow better load balancing of the two terminal servers we have as well as allowing the user to re-establish to the correct server if they get disconnected. My worry is, if I set this up and the server this service is running goes down, does the terminal server stop accepting connections or will they just lose the benefit of having RDCB turned on? I don't want to add another point of failure in this equation unless I have to.

    Read the article

  • Typing math formulas in LaTex and getting them in MathType format?

    - by Tim
    I am asked to type some math formulas that can work in Microsoft Office and MathType equation editor. But I only have access to Ubuntu 12.04 near me, there is LibreOffice available under Ubuntu as well, but I am used to type math formulas in LaTex. So I wonder how to provide math formulas that will work in Microsoft Office and MathType, if I work under Ubuntu, preferably with LaTex but LibreOffice being also acceptable since it is still under Ubuntu? Thanks and regards!

    Read the article

  • 256MB VPS on XEN

    - by user63410
    I am thinking of getting a 256MB server on XEN but not sure is it capable of handling this setup: Varnish + Nginx + Eaccelerator + PHP-FM + MySQL + Mail/FTP? I've tried this setup on OpenVZ and it was partly disastorous, especially with varnish in the equation, i've heard that XEN is better at memory management, sometimes shaving off 50mb or more in comparison to OpenVZ setups... if anyone has any helpful suggestions / input please let me know thanks

    Read the article

  • Developer Profile: Marcelo Quinta

    - by Tori Wieldt
    As the Java developer community lead for Oracle, the best part of my job is going to conferences and meeting Java developers. I’ve had the pleasure to meet men and women who are smart, fun and passionate about Java—they make the Java community happen. The current issue of Java Magazine provides profiles of other young Java developers around the world. Subscribe to read them! Marcelo Quinta Age: 24Occupation: Professor, Federal University of GoiasLocation: Goias, Brazil Twitter: @mrquinta Marcelo (white polo shirt, center) and class OTN: When did you realize that you were good at programming? When I was in graduate school, I developed a Java system that displayed worked out the logics of getting the maximum coverage using the fewest resources (for example, the minimum number of soldiers [and positions] needed for a battlefield. It may seems not difficult, but it's a hard problem to solve, mathematically. Here I was, a freshman, who came up with an app  "solving" it. Some Master's students use my software today. It was then I began to believe in what I could do.OTN: What most inspires you about programming?I'm really inspired by the challenges and tension that comes from solving a complicated problems. Lately, I've been doing a new system focused on education and digital inclusion and was very gratifying to see it working and the results. I felt useful for the community. OTN: What are some things you would like to accomplish using Java?Java is a very strong platform and that gives us power to develop applications for different devices and purposes, from home automation with little microcontrollers to systems in big servers. I would like to build more systems that integrate the people life or different business contexts, from PCs to cell phones and tablets, ubiquitously. I think IT has reached a level where the current challenge is to make systems that leverage existing technologies that are present in daily life. Java gives us a very interesting set of options to put it into practice, especially in systems that require more strength.OTN: What technical insights into Java technology have been most important to you?I have really enjoyed the way that Java has evolved with Oracle, with new features added, many of them which were suggested by the community. Java 7 came with substantial improvements in the language syntax and it seems that Java 8 takes it even further. I also made some applications in JavaFX and liked the new version. The Java GUI is on a higher level than is offered out there. I saw some JavaFX prototypes running in modern tablets and I got excited. OTN: What would you like to be doing 10 years from now?I want my work to make a difference for individuals or an institution. It would be interesting to be improving one of the systems that I am making today. Recently I've been mixing my hobbies and work, playing with Arduino and home automation. The JHome project, winner of the Duke's Choice Award in 2011, is very interesting to me.OTN: Do you listen to music when you write code? If so, what kind?Absolutely! I usually listen to electronic music (Prodigy, Fatboy Slim and Paul Oakenfold), rock (Metallica, Strokes, The Black Keys) and a bit of local alternative music. I live in Goiânia, "The Brazilian Seattle" and I profit from it very well. OTN: What do you do when you're not programming?I like to play guitar and to fish. Last year I sold my economy car and bought a old jeep. Some people called me crazy, but since then I've been having a great time and having adventures on the backroads of Brazil. Once I broke my glasses in a funny game involving my car's suspension and the airbags. OTN: Does your girlfriend think you are crazy?Crazy is someone who doesn't have courage to do strange things! My girlfriend likes my style. =D Subscribe to the free Java Magazine to read profiles of other young Java developers. Visit the Java channel on YouTube to see a video of Marcelo in action.

    Read the article

  • what differs a computer scientist/software engineer to regular people who learn programming language and APIs?

    - by Amumu
    In University, we learn and reinvent the wheel a lot to truly learn the programming concepts. For example, we may learn assembly language to understand, what happens inside the box, and how the system operates, when we execute our code. This helps understanding higher level concepts deeper. For example, memory management like in C is just an abstraction of manually managed memory contents and addresses. The problem is, when we're going to work, usually productivity is required more. I could program my own containers, or string class, or date/time (using POSIX with C system call) to do the job, but then, it would take much longer time to use existing STL or Boost library, which abstract all of those thing and very easy to use. This leads to an issue, that a regular person doesn't need to get through all the low level/under the hood stuffs, who learns only one programming language and using language-related APIs. These people may eventually compete with the mainstream graduates from computer science or software engineer and call themselves programmers. At first, I don't think it's valid to call them programmers. I used to think, a real programmer needs to understand the computer deeply (but not at the electronic level). But then I changed my mind. After all, they get the job done and satisfy all the test criteria (logic, performance, security...), and in business environment, who cares if you're an expert and understand how computer works or not. You may get behind the "amateurs" if you spend to much time learning about how things work inside. It is totally valid for those people to call themselves programmers. This makes me confuse. So, after all, programming should be considered an universal skill? Does programming language and concepts matter or the problems we solve matter? For example, many C/C++ vs Java and other high level language, one of the main reason is because C/C++ features performance, as well as accessing low level facility. One of the main reason (in my opinion), is coding in C/C++ seems complex, so people feel good about it (not trolling anyone, just my observation, and my experience as well. Try to google "C hacker syndrome"). While Java on the other hand, made for simplifying programming tasks to help developers concentrate on solving their problems. Based on Java rationale, if the programing language keeps evolve, one day everyone can map their logic directly with natural language. Everyone can program. On that day, maybe real programmers are mathematicians, who could perform most complex logic (including business logic and academic logic) without worrying about installing/configuring compiler, IDEs? What's our job as a computer scientist/software engineer? To solve computer specific problems or to solve problems in general? For example, take a look at this exame: http://cm.baylor.edu/ICPCWiki/attach/Problem%20Resources/2010WorldFinalProblemSet.pdf . The example requires only basic knowledge about the programming language, but focus more on problem solving with the language. In sum, what differs a computer scientist/software engineer to regular people who learn programming language and APIs? A mathematician can be considered a programmer, if he is good enough to use programming language to implement his formula. Can we programmer do this? Probably not for most of us, since we specialize about computer, not math. An electronic engineer, who learns how to use C to program for his devices, can be considered a programmer. If the programming languages keep being simplified, may one day the software engineers, who implements business logic and create softwares, be obsolete? (Not for computer scientist though, since many of the CS topics are scientific, and science won't change, but technology will).

    Read the article

  • Deliberate Practice

    - by Jeff Foster
    It’s easy to assume, as software engineers, that there is little need to “practice” writing code. After all, we write code all day long! Just by writing a little each day, we’re constantly learning and getting better, right? Unfortunately, that’s just not true. Of course, developers do improve with experience. Each time we encounter a problem we’re more likely to avoid it next time. If we’re in a team that deploys software early and often, we hone and improve the deployment process each time we practice it. However, not all practice makes perfect. To develop true expertise requires a particular type of practice, deliberate practice, the only goal of which is to make us better programmers. Everyday software development has other constraints and goals, not least the pressure to deliver. We rarely get the chance in the course of a “sprint” to experiment with potential solutions that are outside our current comfort zone. However, if we believe that software is a craft then it’s our duty to strive continuously to raise the standard of software development. This requires specific and sustained efforts to get better at something we currently can’t do well (from Harvard Business Review July/August 2007). One interesting way to introduce deliberate practice, in a sustainable way, is the code kata. The term kata derives from martial arts and refers to a set of movements practiced either solo or in pairs. One of the better-known examples is the Bowling Game kata by Bob Martin, the goal of which is simply to write some code to do the scoring for 10-pin bowling. It sounds too easy, right? What could we possibly learn from such a simple example? Trust me, though, that it’s not as simple as five minutes of typing and a solution. Of course, we can reach a solution in a short time, but the important thing about code katas is that we explore each technique fully and in a controlled way. We tackle the same problem multiple times, using different techniques and making different decisions, understanding the ramifications of each one, and exploring edge cases. The short feedback loop optimizes opportunities to learn. Another good example is Conway’s Game of Life. It’s a simple problem to solve, but try solving it in a functional style. If you’re used to mutability, solving the problem without mutating state will push you outside of your comfort zone. Similarly, if you try to solve it with the focus of “tell-don’t-ask“, how will the responsibilities of each object change? As software engineers, we don’t get enough opportunities to explore new ideas. In the middle of a development cycle, we can’t suddenly start experimenting on the team’s code base. Code katas offer an opportunity to explore new techniques in a safe environment. If you’re still skeptical, my challenge to you is simply to try it out. Convince a willing colleague to pair with you and work through a kata or two. It only takes an hour and I’m willing to bet you learn a few new things each time. The next step is to make it a sustainable team practice. Start with an hour every Friday afternoon (after all who wants to commit code to production just before they leave for the weekend?) for month and see how that works out. Finally, consider signing up for the Global Day of Code Retreat. It’s like a daylong code kata, it’s on December 8th and there’s probably an event in your area!

    Read the article

  • morph a sphere to a cube and a a cube to a sphere with GLSL

    - by nkint
    hi i'm getting started with glsl with quartz composer. i have a patch with a particle system in which each particle is mapped into a sphere with a blend value. with blend=0 particles are in random positions, blend=1 particles are in the sphere. the code is here: vec3 sphere(vec2 domain) { vec3 range; range.x = radius * cos(domain.y) * sin(domain.x); range.y = radius * sin(domain.y) * sin(domain.x); range.z = radius * cos(domain.x); return range; } // in main: normal = sphere(p0); * blend + gl_Normal * (1.0 - blend); i'd like the particle to be on a cube if blend=0 i've tried to find but i can't figure out some parametric equation for the cube. mayebe it is not the right way?

    Read the article

  • Frame Interpolation issues for skeletal animation

    - by sebby_man
    I'm trying to animate in-between keyframes for skeletal animation but having some issues. Each joint is represented by a quaternion and there is no translation component. When I try to slerp between the orientations at the two key frames, I got a very wacky animation. I know my skinning equation is right because the animation is perfectly fine when the animation is directly on a keyframe rather than in-between two. I'm using glm's built in mix function to do the slerp, so I don't think there are any problems with the actual slerp implementation. There's really one thing left that could be wrong here. I must not be in the correct space to do slerp. Right now the orientations are in joint local space. Do I have to be in world space? In some other space along the way? I have the bind pose matrix and world-space transformation matrix at my disposal if those are needed.

    Read the article

< Previous Page | 12 13 14 15 16 17 18 19 20 21 22 23  | Next Page >