Posts Tagged ‘ stats ’

Resources for Learning R

May 17, 2011
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The information below will be periodically updated at the folowing permanent link: http://www.backsidesmack.com/r-resources/ Searching for information on R sucks. Not only is the language name a letter of the alphabet (an ignominy it shares with C and some less well known languages), there is Pearson’s r and the coefficient of determination, R squared! if you…

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Using R for Introductory Statistics 6, Simulations

March 21, 2011
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Using R for Introductory Statistics 6, Simulations

R can easily generate random samples from a whole library of probability distributions. We might want to do this to gain insight into the distribution's shape and properties. A tricky aspect of statistics is that results like the central limit theore...

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Using R for Introductory Statistics, The Geometric distribution

March 13, 2011
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Using R for Introductory Statistics, The Geometric distribution

We've already seen two discrete probability distributions, the binomial and the hypergeometric. The binomial distribution describes the number of successes in a series of independent trials with replacement. The hypergeometric distribution describes th...

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Bootstrapping the Truncated Normal Distribution

March 2, 2011
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Bootstrapping the Truncated Normal Distribution

Here’s a post generated from my own ignorance of statistics (as opposed to just being marred by it)! In Labor Economics we walked through something called the truncated normal distribution. Truncated distributions come up a lot in the sciences because … Continue reading →

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Using R for Introductory Statistics, Chapter 5, hypergeometric distribution

February 21, 2011
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Using R for Introductory Statistics, Chapter 5, hypergeometric distribution

This is a little digression from Chapter 5 of Using R for Introductory Statistics that led me to the hypergeometric distribution. Question 5.13 A sample of 100 people is drawn from a population of 600,000. If it is known that 40% of the population h...

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Using R for Introductory Statistics, Chapter 5, Probability Distributions

February 9, 2011
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Using R for Introductory Statistics, Chapter 5, Probability Distributions

In Chapter 5 of Using R for Introductory Statistics we get a brief introduction to probability and, as part of that, a few common probability distributions. Specifically, the normal, binomial, exponential and lognormal distributions make an appearance....

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Null Confusion

January 25, 2011
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Null Confusion

Talking a bit with my friend Jarrod about math stats and econometrics, we both came to the conclusion that the standard presentation for basic inference is lacking. In an intro or intermediate applied statistics course you learn about first and … Continue reading →

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Using R for Introductory Statistics, Chapter 5

January 23, 2011
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Using R for Introductory Statistics, Chapter 5

Any good stats book has to cover a bit of basic probability. That's the purpose of Chapter 5 of Using R for Introductory Statistics, starting with a few definitions: Random variable A random number drawn from a population. A random variable is ...

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R: Attack of the hair-trigger bees?

January 12, 2011
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R: Attack of the hair-trigger bees?

In their book “Complex Adaptive Systems”, authors Miller and Page create a theoretic model for bee attacks, based on the real, flying, honey-making, photogenic stingers. Suppose the hive is threatened by some external creature. Some initial group of guard bees sense the danger and fly off to attack. As they go, they lay down a

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Using R for Introductory Statistics, Chapter 4, Model Formulae

January 10, 2011
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Using R for Introductory Statistics, Chapter 4, Model Formulae

Several R functions take model formulae as parameters. Model formulae are symbolic expressions. They define a relationship between variables rather than an arithmetic expression to be evaluated immediately. Model formulae are defined with the tilde ope...

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