Blog Archives

MLB Baseball Pitching Matchups ~ downloading pitch f/x data using the XML package in R [updatedx6]

May 18, 2010
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MLB Baseball Pitching Matchups ~ downloading pitch f/x data using the XML package in R [updatedx6]

Update x6 (Jul 27): so I guess people want pitch counts. The data @ MLB seems to only give the pitch count of the end result and the strikes/balls/outs of the particular pitch. Of course you can combine them to get the pitch count. Stupid WordPress comments strip out necessary HTML to properly display code,

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Cherry Picking to Generalize ~ NASA Global Temperature Trends ~ enhanced w/ ggplot2

April 12, 2010
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Cherry Picking to Generalize ~ NASA Global Temperature Trends ~ enhanced w/ ggplot2

In a prior article, I tried to visualize the linear global temperatures trends for a grid of start and end years. The visual I created was confusing in that the specification of color scale was interdependent with the data values. I wanted a blue -> white -> red scale of the temperatures indicating cool ->

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Cherry Picking to Generalize ~ NASA Global Temperature Trends

April 6, 2010
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Cherry Picking to Generalize ~ NASA Global Temperature Trends

The relatively (to this decade) cool 2008 global temperatures spurred talks of a warming pause, or even global cooling. The claim usually comes from people who cherry picked either data sets and(!)/or start and end points of the global temperature trends to back up their allegation. The blogosphere already has a lot on this: Skeptical

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R Tools for Dynamical Systems ~ R pplane to draw phase planes

April 5, 2010
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R Tools for Dynamical Systems ~ R pplane to draw phase planes

MATLAB has a nice program called pplane that draws phase planes of differential equations models. pplane on MATLAB is an elaborate program with an interactive GUI where you can just type the model to draw the phase planes. The rest you fidget by clicking (to grab the initial conditions) and it draws the dynamics automatically.

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Lotka-Volterra model ~ intro

March 30, 2010
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Lotka-Volterra model ~ intro

So many know about the Lotka-Volterra model (i.e. the predator-prey model) in ecology. This model portrays two species, the predator (y) and the prey (x), interacting each other in limited space. The prey grows at a linear rate () and gets eaten by the predator at the rate of (). The predator gains a certain

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