An Introduction to Graphviz via R. Kelly’s “Trapped in the Closet” Hip Hopera : Rob's Blog As our world becomes more connected it has become of the utmost importance to clearly and easily visualize the structures that represent the modern digital age: the graph. Anyone involved in object oriented programming, artificial intelligence, networks, social media, or of course the fascinating field of graph theory makes heavy use of these structures. Graphs are a fertile topic that I plan to write more about, but for now we will focus on the immediately practical: the fantastic open source graph visualization toolkit Graphviz. Let us explore some of the useful features of Graphviz and its associated description language “dot” by tracing the convoluted relationships of the characters in R. Like every other web tutorial I will solipsistically assume you are using the same OS I am, Ubuntu. At this point our hero, “Sylvester”, played by R. Now compile: Note this will output a .jpg image but many other output formats are possible. As R. Note red edges signify infidelity.
Caching Tutorial for Web Authors and Webmasters for Web Authors and Webmasters This is an informational document. Although technical in nature, it attempts to make the concepts involved understandable and applicable in real-world situations. What’s a Web Cache? A Web cache sits between one or more Web servers (also known as origin servers) and a client or many clients, and watches requests come by, saving copies of the responses — like HTML pages, images and files (collectively known as representations) — for itself. There are two main reasons that Web caches are used: To reduce latency — Because the request is satisfied from the cache (which is closer to the client) instead of the origin server, it takes less time for it to get the representation and display it. Kinds of Web Caches Browser Caches If you examine the preferences dialog of any modern Web browser (like Internet Explorer, Safari or Mozilla), you’ll probably notice a “cache” setting. Proxy Caches Web proxy caches work on the same principle, but a much larger scale.
AlternativeTo - Social Software Recommendations Bluetooth-Enabling a Panasonic SA-AK33 Logitech’s bluetooth audio receiver is a great device. It has good range, sound, and build quality. The original plan was to put it into my car to add bluetooth reception, but that plan disappeared when it turned into a install-a-new-stereo project. So I had a nice piece of equipment that didn’t have a home until my roommate’s older stereo in the living room popped into mind. I’ll just assume you’re as impatient as me, so here’s a video of the end result! Wires Are For Wimps When I approached my roommate about taking apart his stereo and drilling holes into it, he understandably said “no.” Infrared, that’s what. Blind Reverse Engineering I was lost without a known-good source of infrared commands. I found gold after some extended searching; someone had captured the N2QAGB000002 and submitted timing information to LIRC. I first found the capture with a comment describing the protocol as REC 80 encoded. The N2QAGB000002’s format differs from pure NEC in a few ways: Mixing Glue Code v1.1 Changes
Basics of Memory Addresses in C Memory Addresses It is helpful to think of everything in C in terms of computer memory. Let’s think of computer memory as an array of bytes where each address in memory holds 1 byte. If our computer has 4K of memory for example, it would have 4096 elements in the memory array. When we talk about pointers storing addresses, we are talking about a pointer storing an index to an element in the memory array. Confused about pointers, addresses and dereferencing? Say our computer has 4K of memory and the next open address is index 2048. Running that you should get output like the following: address of charvar = 0x7fff9575c05f address of charvar - 1 = 0x7fff9575c05e address of charvar + 1 = 0x7fff9575c060 address of intvar = 0x7fff9575c058 address of intvar - 1 = 0x7fff9575c054 address of intvar + 1 = 0x7fff9575c05c In the first example on lines 1-5 we declare a char variable, print out the address-of the char, and then print out the address just before and just after the char in memory.
40+ Super Secret OS X Lion Features and Shortcuts OS X Lion has now been around long enough for us all to dig in and really find some interesting functionality that is either completely hidden or just enough below the service that many users don’t even know it exists. We’ve spent hours combing through Lion for secrets and put out a call on Twitter for your favorites. This post brings over forty such hidden tricks and tips for your viewing pleasure. Enjoy! Finder Tricks 1. With Lion came a ton of visual changes to the operating system we know and love. This makes for a really slick looking operating system, but to achieve it Apple had to make some serious functionality sacrifices that I’m not crazy about. Fortunately, this particular problem has a quick fix. The long lost Finder Status Bar 2. Let’s say you have a bunch of stuff scattered across your desktop that you want to throw into a single folder. 3. Did you know you can have Lion auto-merge the contents of two folders? Merging folders 4. Apps arranged by category 5. 6. 7. 8. 9. 10. 11.