Four short links: 19 June 2009

Cute Math, Fast Slo-Mo, Open Source HVAC, xkcd Hack

  1. Inside-Out Multiplication Table — very cool way to view the patterns of factors. Math is beauty with subscripts.
  2. High-Speed Camera — capture 100 frames at up to 1M frames/second. The sample videos, of a bullet liquefying on impact and a shotgun string boiling past, are stunning. The Makezine high-speed photography kit is the cheap amateur version.
  3. Open Source Energy Management for Commercial Buildingsopen source project to enable interoperable applications for integrated Building Automation Systems (BAS). From NovusEdge. I wonder how they’re planning to spread their open source and use it to disrupt. (via earth2tech and timoreilly on Twitter)
  4. xkcd Knapsack Solution — for those of you who like literal Python geeking with your comics. Have a great weekend!
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  • Thr XKCD scenario is a simple problem for brute-force exhaustion, at least for these modest amounts. My inclination would probably have been to use Lisp… start with a node with a balance of $15.05 and no children; now for each appetizer possibility, create a child node with value of appetizer type and balance of its parent less the price of that appetizer, … Read Moreand then recurse. If balance hits zero at a node, the path from that node back to the root is a successful order, and if it’s negative, it’s a failure and recursion stops.