23 karma · joined September 6, 2013
tail -n 1 $f
Tail seeks backwards so it will only read the one line. Of course, this won't give you a line count.EDIT: I haven't tested it but you might be interested in this implementation of tail in python: http://stackoverflow.com/a/136368
Yale economist Bill Nordhaus' Climate Casino is that book. And his research with integrated assessment models concluded:
> The consequences of [climate change] will be costly for human societies and grave for many unmanaged earth systems; the balance of risks indicates that immediate action should be taken to slow and eventually halt emissions of CO2 and other greenhouse gases.
And, by the way, this analysis doesn't even take into account tipping points!
Of course batteries also have power transmission inefficiencies. My intuition though is that wireless power has potential to be more efficient than batteries for two reasons:
- While building out the infrastructue is an enormous proposition, I'd guess that it is much more sustainable to maintain than batteries.
- When the application is propulsion, not having to carry a fuel source (e.g. battery) is huge. On a Tesla Model S, the battery is more than a third of the weight (450kg of 1235kg, according to Wikipedia).
Can someone comment on the game's physics? I am assuming:
- constant horizontal velocity
- gravity
- flapping implemented via impulse
- collisions are handled with bounding boxes
Maybe someone who knows something about optimal control (ODE) say whether this is analytically solvable? Of course there's still the practical stuff (numerical integration, I/O lag) to deal with but I'm optimistic.If an A3 sheet is X units by Y units (with X the long side) and A4 is 2Y units by X units then their ratios are X/Y and 2Y/X, respectively. If these are equal we have
2Y/X = X/Y
cross multiplying gives
2Y^2 = X^2
rearranging and taking a square root (X and Y are positive) gives
X/Y = sqrt(2).
Also one simple way to try to raise money for the site is to use affiliate links to Amazon for any [e]books in the bibliography.
- Let hikes to include GPS route(s) to display on the map.
- Link to the USGS topo map that covers a given hike: http://store.usgs.gov/b2c_usgs/usgs/maplocator/(xcm=r3standa...
- Add a bibliography to each hike.
- Scrape some websites to create "stubs" for new hikes and encourage users to develop these.
- Speaking of stubs, if you are going to have collaboratively edited content why not just build on MediaWiki or similar?
- Use OpenStreetMaps instead of GMaps and encourage users to add trails to OSM.