2533 search results for "Map"

Rationality, and MS Excel (and other calculators)

March 27, 2013
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Rationality, and MS Excel (and other calculators)

This morning, Mathieu had a nice experience in his course on computational method in actuarial science. But let us start with some mathematical formal definitions. First, recall that is – somehow – a standard expression. No one should be surprised to see such an expression. Generally (as explained in http://en.wikipedia.org/… ), this function is defined only when . The...

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Build a search engine in 20 minutes or less

March 27, 2013
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Build a search engine in 20 minutes or less

…or your money back. author = "Ben Ogorek"Twitter = "@baogorek"email = paste0(sub("@", "", Twitter), "@gmail.com") Setup Pretend this is Big Data: doc1 <- "Stray cats are running all over the place. I see 10 a day!"doc2 <- "Cats are killers. They...

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i Before e Except After c

March 26, 2013
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i Before e Except After c

When I went to school we were always taught the “i before e, except after c” rule for spelling. But how accurate is this rule? Kevin Marks tweeted today the following: »@uberfacts: There are 923 words in the English language that break the “I before E” rule. Only 44 words actually follow that rule.« Science— Kevin Marks (@kevinmarks)

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Computing Maritime Routes in R

March 25, 2013
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Computing Maritime Routes in R

Thanks to the attention my paper on the cost of Somali piracy has received, a lot of people have approached me to ask how I computed the maritime routes. It is not a very difficult task using R. The key ingredient is a map of the world, that can be rasterized into a grid; all

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Tupper’s self-referential formula

March 24, 2013
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Tupper’s self-referential formula

Can't remember where I first came across this equation but the Tupper's self referential equation, is a very interesting formula that when graphed in two dimension plane it reproduces the formula. \[ \frac{1}{2} I first thought this would be...

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Parsing complex text files using regular expressions and vectorization

March 24, 2013
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When text data is in a nice CSV format, read.csv is enough to parse it into a useable format. But if this is not the case, getting the data into a useable format is not so straightforward. In this post… See more ›

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Maximum Sharpe Portfolio

March 21, 2013
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Maximum Sharpe Portfolio

Maximum Sharpe Portfolio or Tangency Portfolio is a portfolio on the efficient frontier at the point where line drawn from the point (0, risk-free rate) is tangent to the efficient frontier. There is a great discussion about Maximum Sharpe Portfolio or Tangency Portfolio at quadprog optimization question. In general case, finding the Maximum Sharpe Portfolio

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Violin plots and regional income distribution

March 20, 2013
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Violin plots and regional income distribution

While preparing my slides for statistical graphics, a plot really caught my eye when I was playing around with the data. I started off by plotting the time seriesof GNI per capita by country, and as expected it got quite messy and...

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GeoCoding,R, and The Rolling Stones – Part 2

March 20, 2013
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GeoCoding,R, and The Rolling Stones – Part 2

Welcome to Part 2 of the GeoCoding, R, and the Rolling Stones blog. Let’s apply some of the things we learned in Part 1 to a practical real world example. Mapping the Stones – A Real Example The Rolling Stones have toured for many years. You can go to Wikipedia and see information on the

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GeoCoding,R, and The Rolling Stones – Part 2

March 20, 2013
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GeoCoding,R, and The Rolling Stones – Part 2

Welcome to Part 2 of the GeoCoding, R, and the Rolling Stones blog. Let’s apply some of the things we learned in Part 1 to a practical real world example. Mapping the Stones – A Real Example The Rolling Stones have toured for many years. You can go to Wikipedia and see information on the

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