Monthly Archives: May 2010

Testing Out my Pitch F/X Data

May 25, 2010
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Testing Out my Pitch F/X Data

I recently got all the Pitch F/X data downloaded from Gameday, and have been fiddling around. I certainly don't have the physics knowledge to really talk about the movement at this point, and I'm still acquainting myself with the data format and what e...

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Use SQL queries to manipulate data frames in R with sqldf package

May 25, 2010
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I've covered a few topics in the past including the plyr package, which is kind of like "GROUP BY" for R, and the merge function for merging datasets. I only recently found the sqldf package for R, and it's already one of the most useful packages I've ever installed. The main function in the package is sqldf(), which takes...

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German Tanks, Statistical Intelligence

May 25, 2010
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German Tanks, Statistical Intelligence

In World War II, the Allies had a problem: German tanks were often captured, but how many more did the Nazis have in reserve? Allied intelligence estimated around 1400 Panther tanks were being produced a month: a formidable arsenal, and perhaps an insurmountable one given the much smaller numbers being captured or destroyed. But those captured tanks provided exactly...

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The Kalman Filter For Financial Time Series

May 25, 2010
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The Kalman Filter For Financial Time Series

Every now and then I come across a tool that is so bogged down in pages of esoteric mathematical calculations, it becomes difficult to get even a simple grasp of how or why they might be useful. Even worse, you exhaustively search the internet to find ...

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How many tanks? MC testing the GTP

May 25, 2010
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How many tanks? MC testing the GTP

It’s 1943 and you work for the good guys. A handful of German tanks have been captured, and each one has a serial number. This is back when serial numbers were still presumed to come in serial, one right after the other. Given your collection of numbered tanks, and assuming that any existing tank was

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extrapolation and interpolation The most important lesson I…

May 25, 2010
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extrapolation and interpolation
The most important lesson I…

extrapolation and interpolation The most important lesson I learned from this book:  regression is reliable for interpolation, but not for extrapolation.  Even further, your observations really need to cover the whole gamut of causal variables, inter...

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SQLite as an alternative to shapefiles, and some GPS fun in R

May 24, 2010
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Finally made it out to Folsom Lake for a fine day of sailing and GPS track collecting. Once I was back in the lab, I downloaded the track data with gpsbabel, and was ready to import the data into GRASS. # import GPX from GPS: gpsbabel -t -i...

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Chicago R Meetup: Healthier than Drinking Alone

May 24, 2010
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Chicago R Meetup: Healthier than Drinking Alone

I’m kinda blown away by the number of folks who have joined the Chicago R User Group (RUG) in the last few weeks. As of this morning we have 65 people signed up for the group and 25 who have said that they are planning on attending the meetup this Thursday (yes, only 3 days

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Webinar: R analytics and Business Intelligence dashboards

May 24, 2010
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On Wednesday next week, Revolution will be hosting a joint webinar with open-source Business Intelligence software maker Jaspersoft and open-source Business Intelligence services company OpenBI. Together, we'll be talking about making BI dashboards even more powerful by integrating custom visualizations and advanced predictive models from R. If you create advanced analytics in R and are looking for a way...

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Example 7.38: Kaplan-Meier survival estimates

May 24, 2010
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Example 7.38: Kaplan-Meier survival estimates

In example 7.30 we demonstrated how to simulate data from a Cox proportional hazards model.In this and the next few entries, we expand upon support in R and SAS for survival (time-to-event) models. We'll start with a small, artificial dataset of 19 su...

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