Monday, July 21, 2014

Adding Economic Noise

Two months ago the New York Times had a very informative visualization of monthly economic data with added variability due to sampling error. In the above screen shot we can see how repeated sampling variability can change a steady job growth graph to many different shapes of what it might have looked like with repeated sampling.
Here is another viewing an accelerating job growth graph and one possible result of the same graph with sampling variability showing very stable job growth, via Statistical Modeling ... One commenter there notes how easy it is for us to reading meaning into random noise.

Monday, July 14, 2014

States by Letter

Alphabetical distribution of the first letter of US states, via Flowing Data.

Monday, July 7, 2014

YADDA Frank Lloyd Wright

Yet Another Door Distribution Again (YADDA)

We stayed for two nights, this past Fourth of July weekend, in the Haynes House, a Frank Lloyd Wright designed Usonian home in Fort Wayne, Indiana. Completed in 1952, it has seen much use. Here is a view of one of a pair of cabinet doors in the master bedroom. It shows the pattern of wear that we have seen often, more in a central area around the door knobs, with less wear extending toward the two extremes, a bell-shaped pattern of wear and use, (Thanks Nick).

Monday, June 30, 2014

YADDA Garage Gate

Yet Another Door Distribution Again (YADDA), this one on a gate in a garage stairwell showing a skewed distribution of hand placement opening the door. We've seen and described such patterns often,  (YADDA in our list of labels). Since opening a hinged door is easiest with a long lever arm, more wear is shown near this gate's right-hand edge with less towards the door's pivot, resulting in this skewed pattern of wear.

Monday, June 23, 2014

Tornado Marginals

Inspired by this map of Waffle House restaurants by latitude and similar to global land mass marginal plots we've seen here before and corresponding world population plots, Tim Brice at the National Weather Service (NWS) in Texas produced maps showing the marginal distributions of tornado touchdowns by longitude and latitude.

Here's the joint distribution, a map of tornado tracks from 1950-2013 from the NWS
(Thanks JCT).

Monday, June 16, 2014

The Knotted String

We've seen a paper on the Thrown String. Here is one on the Knotted String.University of California at San Diego physicists Raymer and Smith place various lengths of string in a box and film it tumbling for ten seconds. More specifically from their PNAS paper "Spontaneous knotting of an agitated string,"
Most of the measurements were carried out with a string having a diameter of 3.2 mm, a density of 0.04 g/cm, and a flexural rigidity of 3.1 × 104 dynes·cm2, tumbling in a 0.30 × 0.30 × 0.30-m box rotated at one revolution per second for 10 sec.
Results from 200 trials noted the proportion of knots formed for various lengths. These results are plotted above. The dependence of this knotted probability on other physical properties of the string are shown in their table below:
They conjecture that the string confinement and rotation promote braiding at the ends of the string, producing the knots. As one report noted  Apple's iPhone earbuds are 139 cm (55 inches) long and thus right at the 50% tangle-rate-sweet-spot at the top of the curve. Shorter earbuds would be welcome.

Monday, June 9, 2014

Tri-modal Beach Bench

♫ "On the Boardwalk in Atlantic City".