Monthly Archives: April 2012

Add a frame to a map

April 2, 2012
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Add a frame to a map

Here is a function that adds a frame of alternating colors to a map (un-projected). One defines the extension of each bar (in degrees) and an optional width of the bars (in inches). It uses the "joinPolys" function of the package to trim the bars near the map corners where the axes meet.the map.frame...

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3-D graphing with Google

April 2, 2012
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3-D graphing with Google

You probably already knew that you can draw mathematical equations in Google by typing the equation into the search box. For example, here's the Standard Normal density function: I can't find a way to embed the graph directly, but if you click on it you'll find it's interactive: you can inspect points, zoom in/out etc. You can create a...

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Playing with fire (or water)

April 2, 2012
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Playing with fire (or water)

A few days ago, http://www.futilitycloset.com/ published a short post based on the fourth problem of the 1987 Canadian Mathematical Olympiad (from on a problem from the 6th All Soviet Union Mathematical Competition in Voronezh, 1966). The problem i...

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Example 9.25: It’s been a mighty warm winter? (Plot on a circular axis)

April 2, 2012
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Example 9.25: It’s been a mighty warm winter? (Plot on a circular axis)

Updated (see below)People here in the northeast US consider this to have been an unusually warm winter. Was it?The University of Dayton and the US Environmental Protection Agency maintain an archive of daily average temperatures that's reasonably current. In the case of Albany, NY (the most similar of their records to our...

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Surveys, Assumptions, and the Need for Data Collection Alternatives

April 2, 2012
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Surveys, Assumptions, and the Need for Data Collection Alternatives

This is a long post. My previous posts have mostly been about my thoughts on various research subjects. This one reports an actual analysis. If you don’t want to read the whole thing, here are the highlights: We really need to stop using surveys so much. If we have to use surveys, it’s probably best

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My main resources for R programming

April 2, 2012
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My main resources for R programming

In this article, you will find a list of Internet resources that may be useful if you are programming in R. If you have a problem with R and

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Linking apples liking to analytical data

April 2, 2012
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Linking apples liking to analytical data

This post describes the last puzzle piece of the model. The link of instrumental to sensory data. Together with the previous pieces this leads to a model starting from physico-chemical measurements, to sensory data, to consumers' perception and finally...

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Simple data mining and plotting data on a map with ggplot2

April 2, 2012
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Simple data mining and plotting data on a map with ggplot2

In this post I use OpenStreetsMaps and ggplot2 to plot geographically were psychologists live, using data from a facebook document.

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Replacing market indices

April 2, 2012
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Replacing market indices

If equity markets suddenly sprang into existence now, would we create market indices? I’m doubtful. Why an index? The Dow Jones Industrial Average was born in 1896.  This was when computers were humans with adding machines (but they did do parallel processing).  At that point boiling “the market” down to a single number had value. … Continue reading...

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Sunday evening, stupid games…

April 1, 2012
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Sunday evening, stupid games…

This evening, while I was about to wash the dishes, I heard my elders starting a game (call them Him and Her) Him: "I have picked - in my head - a number, lower than 50. Try to guess..." Her: "No way, too difficult..." Him: "You can try five differ...

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