Category: statistics

Past performance is no indication of future…

I am such a slow pony.  I’ve just web-surfed my way into discovering Rob Hyndman’s Time Series Data Library, which has hundreds of time-series datasets suitable for every teaching need.  I was looking for one of my old faves, from that hoary old classic, Forecasting, Time Series, and Regression, and voila! there it is.

monthly-hotel-occupied-room-av

 

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To every thing, there is a season

Most of us are aware of the seasonal cycle of influenza outbreaks, which for Americans peak in the winter. In a new paper, Micaela Martinez, PhD, a scientist at the Columbia University Mailman School of Public Health, makes a case that all infectious diseases have a seasonal element. The “Pearl” article appears in the journal PLOS Pathogens. [my emphasis]

We all knew this, we just didn’t know we knew this.  Some folks are recognized as geniuses for explicating the obvious.  I’m look at you, Micaela Martinez.

CalendarOfEpidemics

Tip from Austin Bay writing at the Instatpundit,  who, like the BlogFather himself, can make even the most boring stuff sound interesting.

Hunting the Wild Placebo

The New York Times’ Gary Greenberg asks “What if the Placebo Effect Isn’t a Trick?” and gets some interesting answers.  Along the way, he tells the interesting history of the placebo and how it has become a standard in FDA=approved clinical trials.  My only question for the FDA is this:  if someone were to attempt to certify a placebo effect, what would you compare it to?PlaceboElixir
Tip from Drudge, who, like a blind squirrel, occasionally finds a fresh nut, and never leaves a permalink.

The Fourier Transform, explained beautifully

At the Better Explained blog, Kalid Azad hits another home run with An Interactive Guide to the Fourier Transform.

Here’s a plain-English metaphor:

  • What does the Fourier Transform do? Given a smoothie, it finds the recipe.
  • How? Run the smoothie through filters to extract each ingredient.
  • Why? Recipes are easier to analyze, compare, and modify than the smoothie itself.
  • How do we get the smoothie back? Blend the ingredients.

Here’s the “math English” version of the above:

  • The Fourier Transform takes a time-based pattern, measures every possible cycle, and returns the overall “cycle recipe” (the amplitude, offset, & rotation speed for every cycle that was found).

smoothie-to-recipe

Tip from Kotke, who has a cool Fourier Transform video.

Whether to ask the question invites an answer

The Justice Department and the Census Bureau are engaged in a kerfuffle over the 2020 Census.  It’s all about a question of citizenship: “What country are you a citizen of?”  With the inevitable congressional reapportionment that occurs based on the Census, this is a question that many states really don’t want to know the answer to.

My take:  the Census Bureau has been crying poor for years now.  The Trump Administration should jawbone Congress into increasing the Bureau’s funding, but only if they ASK THE QUESTION (and report the answers).

Update:  Now folks should really be worried.  Combine citizenship data with Google location data (“we have ways to make you opt in”), and some dedicated data miners could find every Android-using illegal alien in the country.

Tips from the Instapundit, where the signal-to-noise ratio seems to be increasing lately.

Update:  It has come to my attention that at least one other branch of the federal government already ASKS THE QUESTION, to wit, the Justice Department’s Bureau of Alcohol, Tobacco, Firearms, and Explosives* E-Form 4473, Firearms Transaction Record has Questions 12 and 13:

ATFE4473_AskTheQuestion

In other words, you cannot exercise your 2nd Amendment right to own a firearm unless you ANSWER THE QUESTION.

* Or what I call a Redneck Hedge Fund.

Our National Blind Spot

Want to save the planet?  How about starting by saving the birds.  Here’s a Pareto graph that gives a strong hint of where to start:

BirdMortality

That’s right, get the cat population under control.  Eradicate feral cat colonies, and euthanize cat collections (oh, and institutionalize obsessive cat ladies).  The whole country needs to grow up and get that “cute little kitty” lie out of their heads, and replace it with something more realistic, like “bird murderer.”

Tip from Bird Note, by way of Sarah Hoyt at the Instapundit.

Update:  One Dallas suburb is infested with feral cats, protected by a well-connected cat lady.