R is a powerful tool for statistics and graphics, but getting started with this language can be frustrating. This short, concise book provides beginners with a selection of how-to recipes to solve simple problems with R. Each solution gives you just what you need to know to use R for basic statistics, graphics, and regression.
There is a simple recipe for preventing accidents: see and be seen. But vision is a complex process. Road lighting needs to take account of that. Daylight illuminance ranges from 5,000 to 100,000 lux (lx). On a moonlit night, it reaches 0.25 lx at most. The fact that we can “see” over this vast brightness range is due to the eye’s ability to adapt.