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1. Top results related to what are the main software categories

   • What are the main differences between the PSR-2 coding standard and the Symfony2 code standard for phpcs?

     Top Answer

     Answered Jun 18, 2015 · 21 votes

     The Symfony coding standards basically extend the PSR standards. PSR-2 doesn't specify rules for all situations, so the Symfony standards add some rules on top of PSR-2.

     As you said the PHP CodeSniffer repository doesn't include a ruleset for Symfony. There are multiple third-party implementations of a Symfony2 ruleset, so the exact list of differences between them and the PSR-2 ruleset depends on the implementation you choose.

     However, when looking to the differences between the standards of Symfony and PSR (not the rulesets for PHP CodeSniffer), some additions by the Symfony standards are:

     • Not adding spaces around the concatenation operator ( .)
     • Adding a comma after each array item in a multi-line array, even after the last one
     • Adding a blank line before return statements (unless the return is alone inside a statement-group (like an if statement))
     • Declaring class properties before methods
     • Declaring public members first, then protected, then private (except class constructors and the setUp and tearDown methods for PHPUnit classes)

     These are just some examples, take a look at the Symfony coding standards for the full list.

     In my opinion the Symfony standards make sense and I try to use them whenever I can, even outside of Symfony projects.

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     1/5

   • What are the main differences between the Knuth-Morris-Pratt and Boyer-Moore search algorithms?

     Top Answer

     Answered Sep 29, 2012 · 44 votes

     Moore's UTexas webpage walks through both algorithms in a step-by-step fashion (he also provides various technical sources):

     • Knuth-Morris-Pratt
     • Boyer-Moore

     According to the man himself,

     The classic Boyer-Moore algorithm suffers from the phenomenon that it tends not to work so efficiently on small alphabets like DNA. The skip distance tends to stop growing with the pattern length because substrings re-occur frequently. By remembering more of what has already been matched, one can get larger skips through the text. One can even arrange ``perfect memory'' and thus look at each character at most once, whereas the Boyer-Moore algorithm, while linear, may inspect a character from the text multiple times. This idea of remembering more has been explored in the literature by others. It suffers from the need for very large tables or state machines.

     However, there have been some modifications of BM that have made small-alphabet searching viable.

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     2/5

   • What are the main references to the fish-eye camera model in OpenCV3.0.0dev?

     Top Answer

     Answered Apr 01, 2019 · 26 votes

     Short answer:

     OpenCV 3.0.0 Fisheye camera model doesn't use the Brown model nor any of the models that the OP refers from Panotools, it uses a Generic Camera Model by Juho Kannala and Sami S. Brandt.

     Detailed answer:

     As Cfr points in his answer, this comment from Ilya Krylov (who implemented the fisheye model in OpenCV) says they ported the Camera Calibration Toolbox for Matlab of Jean-Yves Bouguet:

     Jean-Yves Bouguet website (link), in turn, mentions the paper A Generic Camera Model and Calibration Method for Conventional, Wide-Angle, and Fish-Eye Lenses, and says :

     The "undocumented" fisheye model contained in the calibration toolbox follows the equidistance projection model described by equation (3) in this very nice paper. The distortion model follows equation (6), to the exception that k1=1 (otherwise indistinguishable from f).

     Which in my opinion is a misleading statement or a plain misconception as equation(3) and equation(6) correspond to different models: equation (6) is the actual model introduced in this paper which the authors refer as the Generic Camera Model (hence the name of the paper). To be more precise, equation (6) was meant to be used as the camera model and equation (8) and (9) as the "distortion" or deviation from this model.

     But the odyssey is not over. OpenCV's implementation (according to its documentation) first computes the pinhole projection to find the field angle (the angle between the 3D point, the center of projection and the optical axis). This means you can't use their fisheye model to project rays at 90º (or you would divide by 0) or close to 90º (numerical stability problems, like overflow could happen if z is small enough). Moreover I'm not sure whether it will work for rays for more than 90º. All this makes me really wonder the "usefulness" of their fisheye camera model for fisheye or wide angle lenses.

     In case you're skeptic about that you can take a look at OpenCV's source code, concretely at sources\modules\calib3d\src\fisheye.cpp (I added some comments)

     void cv::fisheye::projectPoints(InputArray objectPoints, OutputArray imagePoints, InputArray _rvec,InputArray _tvec, InputArray _K, InputArray _D, double alpha, OutputArray jacobian){ ... Rodrigues(om, R, dRdom); Affine3d aff(om, T); ... Vec3d Xi = objectPoints.depth() == CV_32F ? (Vec3d)Xf[i] : Xd[i]; Vec3d Y = aff*Xi; /* To transform to camera reference frame*/- Vec2d x(Y[0]/Y[2], Y[1]/Y[2]); /* <- The root of all evil (division by z) */- double r2 = x.dot(x); double r = std::sqrt(r2);- // Angle of the incoming ray: double theta = atan(r);- double theta2 = theta*theta, theta3 = theta2*theta, theta4 = theta2*theta2, theta5 = theta4*theta, theta6 = theta3*theta3, theta7 = theta6*theta, theta8 = theta4*theta4, theta9 = theta8*theta;- double theta_d = theta + k[0]*theta3 + k[1]*theta5 + k[2]*theta7 + k[3]*theta9;- double inv_r = r > 1e-8 ? 1.0/r : 1; double cdist = r > 1e-8 ? theta_d * inv_r : 1;- Vec2d xd1 = x * cdist; Vec2d xd3(xd1[0] + alpha*xd1[1], xd1[1]); Vec2d final_point(xd3[0] * f[0] + c[0], xd3[1] * f[1] + c[1]); ...}-

     Update: This pull request fixes the problem with rays at angles ≥ 90º. As of April 2018 it hasn't been merged into master yet but is being considered for OpenCV 4.x Calibration Module (check calibration module discussion too)

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     3/5

   • What are the main concepts in the laravel framework?

     Top Answer

     Answered Oct 10, 2015 · 11 votes

     Basically all you need to know is very well documented at the official documentation, Taylor Otwell made a huge effort doing the documentation to make the framwork more comprenhensible.

     The basic concepts are:

     • Routing
     • Controllers
     • Views
     • Blade templating
     • Requests and Responses
     • Models & Migrations

     After that keep an eye to in the Middleware concept, also there's a plenty of built-in services as: Auth, Pagination, Encryption, etc... check them out.

     Something you'll love is Eloquent ORM, it simplifies the interaction with the database.

     Laravel community has their own site and that is laracasts you could get help there too.

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     4/5

   • What are the main reasons against the Windows Registry?

     Top Answer

     Answered Apr 08, 2010 · 8 votes

     I once worked on a kernel based solution but stopped because others said that registries are useless (because the windows registry is)... what do you think?

     A kernel-based registry? Why? Why? A thousand times, why? Might as well ask for a kernel-based musical postcard or inetd for all the point it is putting it in there. If it doesn't need to be in the kernel, it shouldn't be in. There are many other ways to implement a privileged process that don't require deep hackery like that...

     If i want to develop a registry-like System for Linux, which Windows Registry design failures should i avoid?

     • Make sure that applications can change many entries at once in an atomic fashion.
     • Make sure that there are simple command-line tools to manipulate it.
     • Make sure that no critical part of the system needs it, so that it's always possible to boot to a point where you can fix things.
     • Make sure that backup programs back it up correctly!
     • Don't let chunks of executable data be stored in your registry.

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     5/5

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2. www.geeksforgeeks.org › software-and-its-typesWhat is Software? Definition, Types, Examples, and More -...

   www.geeksforgeeks.org › software-and-its-types

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   Aug 29, 2023 · You need software in order for the computer to operate effectively. It is a collection of data that is given to the computer to complete a particular task. three main categories of software are application software, programming software, and system software.

3. enosta.com › insights › types-of-softwareDifferent Types of Software: What are they & Examples

   enosta.com › insights › types-of-software

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   Here are some major categories of application software. Productivity Software. Productivity software includes tools that enhance efficiency and streamline work-related tasks. Examples include word processors, spreadsheets, presentation software, project management tools, and note-taking applications.

4. softwarelab.org › blog › what-is-softwareWhat is Software? Everything You Need to Know

   softwarelab.org › blog › what-is-software

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   Software can be divided into three basic categories: system software, utility software, and application software. System software provides the basis for computing operations while utility software keeps it running smoothly. Application software allows users to do useful tasks.

5. www.businessinsider.com › guides › techWhat Is Software? a Guide to All of the Different Types - ...

   www.businessinsider.com › guides › tech

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   Mar 26, 2021 · Mar 26, 2021, 10:44 AM PDT. Software consists of code that dictates how a computer operates. Chalirmpoj Pimpisarn/EyeEm/Getty Images. Software is computer code that tells a computer how...

6. zapier.com › blog › business-software-categories-explainedThe Software Categories Guide: What Work Apps Do - Zapier

   zapier.com › blog › business-software-categories-explained

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   Oct 16, 2017 · The 14 Core Categories of Business Software. Email. Chat. Calls. Social. Contacts. Calendar. Files. Data. Documents. Design. Development. Commerce. Finance. Tasks. Email apps are the original way to communicate digitally (Microsoft Outlook pictured)

7. www.coderus.com › software-101-a-complete-guide-to-the-different-types-of-softwareA Complete Guide to Different Types of Software | Coderus

   www.coderus.com › software-101-a-complete-guide-to-the-different-types-of-software

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   Nov 10, 2020 · Firmware. Programming Software. Driver Software. Freeware. Shareware. Open Source Software.

8. www.britannica.com › technology › softwareSoftware | Definition, Types, & Facts | Britannica

   www.britannica.com › technology › software

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   Apr 19, 2024 · A set of instructions that directs a computer’s hardware to perform a task is called a program, or software program. The two main types of software are system software and application software.