CourseWiki - CS 448B. The world is awash with increasing amounts of data, and we must keep afloat with our relatively constant perceptual and cognitive abilities. Visualization provides one means of combating information overload, as a well-designed visual encoding can supplant cognitive calculations with simpler perceptual inferences and improve comprehension, memory, and decision making. Furthermore, visual representations may help engage more diverse audiences in the process of analytic thinking. In this course we will study techniques and algorithms for creating effective visualizations based on principles from graphic design, visual art, perceptual psychology, and cognitive science.
The course is targeted both towards students interested in using visualization in their own work, as well as students interested in building better visualization tools and systems. There are no prerequisites for the class and the class is open to graduate students as well as advanced undergraduates. Schedule Fri Nov 2: Chart for Learning a Programming Langauge | Zappable. Documentation : : Ffmpeg [] {[] -i ‘input_file’} ... {[] ‘output_file’} ... ffmpeg is a very fast video and audio converter that can also grab from a live audio/video source. It can also convert between arbitrary sample rates and resize video on the fly with a high quality polyphase filter. ffmpeg reads from an arbitrary number of input "files" (which can be regular files, pipes, network streams, grabbing devices, etc.), specified by the -i option, and writes to an arbitrary number of output "files", which are specified by a plain output filename.
Anything found on the command line which cannot be interpreted as an option is considered to be an output filename. Each input or output file can, in principle, contain any number of streams of different types (video/audio/subtitle/attachment/data). The allowed number and/or types of streams may be limited by the container format. To refer to input files in options, you must use their indices (0-based). The format option may be needed for raw input files.
‘p:[:]’ Video Listing. Systems Programming at Twitter. Facebook, October 30, 2012 Marius Eriksen Twitter Inc. (Press space or enter to navigate to the next slide, left arrow to go backwards.) A history lesson Twitter evolves 2009: Pure Ruby-on-Rails app with MySQL; lots of memcache. This is the context of our work. Late 2012 architecture Many open source components Memcache, redis, MySQL, etc. Organized around services Distinct responsibilities Isolated from each other Distributed computation and data RPC between systems Multiplexing HTTP frontend Crucial for modularity, load balancing A systems software stack Programming the datacenter Concerns include Partial failures Deep memory hierarchies Split heaps Dynamic topologies Changes in variance, latency tails Heterogeneous components Operator errors Taming the resulting complexity is the central theme of our work. Languages and tools Mismatch of world views: Languages and tools target single computers, but our applications demand the simultaneous use of 1000s—a datacenter!
Concurrent systems Desiderata Scala Stats. LinkedIn Signal: A Case Study for Scala, JRuby and Voldemort. How to Crack the Toughest Coding Interviews, by Gayle McDowell, ex-Google Engineer & hiring committee member. [A guest blog post for Geeklist by Gayle Laakmann McDowell. Gayle is the founder / CEO of CareerCup, and the author of Cracking the Coding Interview (Amazon.com’s #1 best-selling interview book) and The Google Resume. Gayle has worked a software engineer for Microsoft, Apple and Google, and served on Google’s hiring committee.
You can follow her on Twitter, Facebook, Quora, or her blog.] We’ve all heard the scary stories about Google interview questions. What would you do if you were shrunk to the size of a nickel and stuck in a blender? The good news is that most of these questions are fake. What to Expect in a Technical InterviewA typical interview for software engineers at top tech companies will be based in coding, data structures, algorithms, and system design questions. These questions are designed to test your knowledge of computer science fundamentals (namely data structures and algorithms) in addition to your problem solving and coding skills. How efficient was your algorithm? Learning to write GOOD JavaScript. Easy, proactive monitoring of processes, programs, files, directories and filesystems on Linux/Unix | Monit. How To Set Up Your Linode For Maximum Awesomeness » Feross.org. So, you followed the advice in my Linode Hosting Review and decided to host your website with Linode.
Excellent choice! But, if you’re new to the command line (perhaps you are familiar with CPanel or Plesk?) Or you’ve never setup a server from scratch before, you may be wondering what dark magic vudu is required to get up and running. Well, you’ve come to the right place! The Command Line Is Hard (…at first) I’ve set up at least five new servers with Linode and each time I complete the ritual, I learn new incantations that make the Linux angels sing. I’m pretty happy with my current recipe. Setting up a new server can be confusing, so using a tutorial like this one is a good idea the first time you do it. Tutorial: How To Set Up Your Linode A Note About This Guide I originally compiled this guide as a .txt file of notes for myself, but decided to share it in case anyone finds it useful. Let’s get started! Provision a New Linode First, you need to provision a new Linode. Connecting to Your Server.
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How do I run a Unix process in the background. In Unix, a background process executes independently of the shell, leaving the terminal free for other work. To run a process in the background, include an & (an ampersand) at the end of the command you use to run the job. Following are some examples: To run the count program, which will display the process identification number of the job, enter: count &To check the status of your job, enter: psTo bring a background process to the foreground, enter: fgIf you have more than one job suspended in the background, enter: fg %# Replace # with the job number, as shown in the first column of the output of the jobs command.You can kill a background process by entering: kill PID Replace PID with the process ID of the job.
If that fails, enter the following: kill -KILL PIDTo determine a job's PID, enter: jobs -lIf you are using sh, ksh, bash, or zsh, you may prevent background processes from sending error messages to the terminal. Everything Sysadmin: 4 unix commands I abuse every day. 1. grep dot (view the contents of files prefixed by their filename) I want to view the contents of a few files but I want each line prepended with the the file's name. My solution?
$ grep . *.txt jack.txt:Once upon a time jack.txt:there was a fellow named Jack. lyingryan.txt:Now that "trickle down economics" has been lyingryan.txt:tested for 30 years and the data shows it lyingryan.txt:has been a total failure, candidates lyingryan.txt:still claim that cutting taxes for lyingryan.txt:billionaires will help the economy. market.txt:Jack went to market to sell the family market.txt:cow. market.txt:He came back with a handful of magic beans. $ grep is a search tool. Why am I using it like a weird version of cat? Note that ". " matches lines with at least 1 character. Example use: The other day I grabbed the /etc/network/interfaces file from 6 different Linux boxes. 2. Let's look at another way to accomplish my example of comparing 6 files. . $ for i in *.txt ; do echo === $i === ; cat $i ; done. Web Tutorials and Resources That Don't Suck.