Project Euler

proyeccion de 3d a 2d - Matemáticas Son matrices, lo que ocurre es que el programa de Todoexpertos elimina los espacios. De todas formas es equivalente lo siguiente: x' = x*cos(a) -y*sen(a) y' = x*sen(a) +y*cos(a) z' = z donde a es el ángulo que rota el eje OZ. x' = x*cos(b) -z*sen(b) y' = y z' = x*sen(b) + z*cos(b) y b es lo que has rotado el eje OY hasta ese momento. x' = x y' = y*cos(c) -z*sen(c) z' = y*sen(c) + z*cos(c) Rotas primero sobre OZ (con la variable a, que es el ángulo este), y obtienes x1, y1, z1, y estos los pones en las segundas fórmulas a la derecha y obtienes x2, y2, y3, y estos los pones en las terceras fórmulas a la derecha, y obtienes x3, y3, z3, que serán las coordenadas del punto una vez rotados los tres ejes. Con respecto a esto último, hay unas fórmulas en el web que pone lo siguiente (parece que se trata de un programador de gráficos): m_ancho = ancho_pantalla / 2; m_alto = alto_pantalla / 2; x_pantalla = (+(x_3D / z_3D) + m_ancho) * m_ancho; y_pantalla = (-(y_3D / z_3D) + m_alto) * m_alto;

Anaconda Anaconda is a completely free Python distribution (including for commercial use and redistribution). It includes over 195 of the most popular Python packages for science, math, engineering, data analysis. You can find MD5 information for Anaconda installers here. *Anaconda comes with installers for Python 2.7 and 3.4. If you do not want to download the entire distribution, Miniconda is also available. For older versions of Anaconda installers, visit the installer archive. Using a cloud service account on Amazon AWS, Microsoft Azure, or VMDepot? NumFOCUS NumFOCUS is a charitable organization with the purpose of supporting and promoting world-class, innovative, open-source scientific software.

15 feminist-improved pages for the computer engineer Barbie book Only the Internet can save Barbie from misogyny. In the book I Can Be a Computer Engineer, Barbie wants to be, as the title states, a computer engineer — which is a fantastic premise, in theory. In actuality (and in the book), Barbie needs the help of two men to code a computer program for her instead of doing it herself. Cue massive eye roll. If the book's plot wasn't enough, the artwork features bright pink laptops and sparkly, heart-shaped flash drives to really drive home the frilly girliness of Barbie instead of making her seem like a capable role model for young girls. Tumblr site Feminist Hacker Barbie is turning the groan-worthy story on its head by letting users submit their own, improved versions — complete with programmer lingo. Not only is Barbie doing her own coding, she's taking everyone to school. Show As Gallery

10 Puzzle Websites to Sharpen Your Programming Skills Solving programming puzzles is a fun way to develop your logical and problem solving abilities. Also, when you’re familiarizing yourself with a new programming language, solving puzzles for that language can help speed up the learning process. Here are the top 10 popular programming puzzle sites that will help test your thinking and improve your programming, problem solving, and logical thinking skills. 1. Programming Praxis is a blog that includes a range of interesting problems with solutions usually available in several different programming languages. 2. CodeKata is a blog of programming puzzles written by Dave Thomas, who’s most famous for the groundbreaking book, Pragmatic Programmer. 3. TopCoder is an active programming community of developers who love to solve puzzles. 4. 5. Facebook has a collection of very challenging programming puzzles that–should you manage to solve them–could result in you getting a job at Facebook! 6. 7. 8. 9. 10. 99 Prolog Problems * Bonus: Mind Cipher

Quackwatch Vitutor SublimeLinter/SublimeLinter Linux File Permissions Tutorial December 14, 2011By Roman Rafacz What we’ll cover in this article is how to identify permissions for files & directories and how to change them, as well as changing ownerships, groups, etc. Depending on what you want to do, you’ll want to make sure you have the appropriate permissions (obviously), so let’s find out how to change them. Let’s start by making a file we can use. I issued the “touch” command to make a file creatively named testfile. Touch will just create an empty file but has all the same attributes as an actual file. Commands: touch test file mkdir workfolder The permisions are broken into 4 sections. chmod – adds and removes permissions If you wanted to add or remove permissions to the user, use the command “chmod” with a “+” or “–“, along with the r (read), w (write), x (execute) attribute followed by the name of the directory or file. chmod +rwx “name of the file” chmod –rwx “name of the directory” chmod +x testfile – this would allow me to execute chmod g+w testfile Examples: 1 = –x

8 Online Programming Contests Today, many companies take advantage of the drawing power of contests to draw out the power of the crowd. We have taken a look at photo contests and design contests before. Then there is Google with its lineup of contests you should keep an eye on. One of the contests Google hosts is CodeJam; its annual programming competition. Google is of course not alone when it comes to calling up the brightest minds. So, if you fancy yourself with a programming language, brush off the cobwebs, be mindful of your intellectual property rights and dive into some contests that are held in the online world. Top Coder TopCoder is the world’s largest competitive software development community spread over 200 countries and 272,348 members. Codechef Codechef is a noncommercial programming community that’s Indian in origin but global in scope with nearly 25,000 members. Calling All Innovators Nokia’s worldwide contest covers eco-friendly applications, entertainment, productivity, and life improvement. Bitwise

Simple animation to explain complex principles - Electronics 1, aircraft radial engine 2, oval Regulation 3, sewing machines 4, Malta Cross movement - second hand movement used to control the clock 5, auto change file mechanism 6, auto constant velocity universal joint 6.gif 7, gun ammunition loading system 8 rotary engine - an internal combustion engine, the heat rather than the piston movement into rotary movement # Via World Of Technology. 1, inline engine - it's cylinders lined up side by side 2, V-type engine - cylinder arranged at an angle of two plane 3, boxer engine - cylinder engine arranged in two planes relative Completar cuadrados "Completar el cuadrado" es cuando... Pero si tienes tiempo, deja que te explique cómo llegar allá. La pista Primero tengo que enseñarte lo que pasa cuando desarrollas (x+d)2 (x+d)2 = (x+d)(x+d) = x(x+d) + d(x+d) = x2 + 2dx + d2 El caso más simple El completo Ahora vamos al caso completo: Ejemplo Vamos a probar con un ejemplo de verdad: ¿Para qué "completar el cuadrado"? ¿Para qué querrías completar el cuadrado cuando basta usar la fórmula cuadrática para resolver una eciación cuadrática? Bueno, la respuesta está arriba en parte, donde la forma nueva te da el vértice, y también hace la ecuación fácil de resolver. Es el primer paso en la derivación de la fórmula cuadrática A veces la forma "ax2 + bx + c" puede ser parte de un problema más grande y escribirla como "a(x+d)2 + e" hace más fácil llegar a la solución, porque la "x" sólo aparece una vez. Por ejemplo es difícil integrar 1/(3x2 - 4x - 6) pero 1/(3(x - 4/6)2 - 22/3) es más fácil. Es sólo otra herramienta en tu caja de herramientas matemáticas.