2648 search results for "gis"

Backtesting Part 2: Splits, Dividends, Trading Costs and Log Plots

September 16, 2011
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Backtesting Part 2: Splits, Dividends, Trading Costs and Log Plots

Note: This post is NOT financial advice!  This is just a fun way to explore some of the capabilities R has for importing and manipulating data.   In my last post, I demonstrated how to backtest a simple momentum-based stock trading strategy ...

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Soil Series Query for SoilWeb

September 16, 2011
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Soil Series Query for SoilWeb

A map depicting the spatial distribution of a given soil series can be very useful when working on a new soil survey, updating an old one, or searching for specific soil characteristics. We have recently added a soil series query facility to SoilWeb, w...

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Simulation studies in R – Using all cores and other tips

September 16, 2011
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After working more seriously with simulations I noticed some updates were necessary to my previous setup. Most notably are the following three: It is very handy to explicitly call the different scenarios instead of using nested loops Storing intermediate results in single files obliviates the need to rerun an almost finished but crashed analysis and

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Correlations among US Stocks: Is it really time to fire your adviser?

September 15, 2011
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Correlations among US Stocks: Is it really time to fire your adviser?

Note: This post is NOT financial advice!  This is just a fun way to explore some of the capabilities R has for importing and manipulating data. The Financial Times says it's time to "Fire your Adviser" because correlations among US stocks ar...

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Revolution Analytics Fall Webinar Series

September 14, 2011
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We've lined up what we think is an amazing series of R-related webinars over the next couple of months. These free 30-60 minute webinars will cover a wide range of topics: big-data analysis in R with the RevoScaleR package, Hadoop and Netezza; introductions to R for SAS users and for R users new to Revolution R; and applications of...

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Example 9.5: New stuff in SAS 9.3– proc FMM

September 13, 2011
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Example 9.5: New stuff in SAS 9.3– proc FMM

Finite mixture models (FMMs) can be used in settings where some unmeasured classification separates the observed data into groups with different exposure/outcome relationships. One familiar example of this is a zero-inflated model, where some observat...

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How to program MapReduce jobs in Hadoop with R

September 13, 2011
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MapReduce is a powerful programming framework for efficiently processing very large amounts of data stored in the Hadoop distributed filesystem. But while several programming frameworks for Hadoop exist, few are tuned to the needs of data analysts who typically work in the R environment as opposed to general-purpose languages like Java. That's why the dev team at Revolution Analytics...

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Backtesting a Simple Stock Trading Strategy

September 13, 2011
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Backtesting a Simple Stock Trading Strategy

Note: This post is NOT financial advice!  This is just a fun way to explore some of the capabilities R has for importing and manipulating data.   I recently read a post on ETF Prophet that explored an interesting stock trading strategy in Ex...

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Visualizing Bayesian Updating

September 10, 2011
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Visualizing Bayesian Updating

One of the most straightforward examples of how we use Bayes to update our beliefs as we acquire more information can be seen with a simple Bernoulli process. That is, a process which has only two  possible outcomes. Probably the most commonly thought of example is that of a coin toss. The outcome of tossing

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Getting data from the Infochimps Geo API in R

September 10, 2011
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Getting data from the Infochimps Geo API in R

I am very intrigued by the Infochimps Geo API, so wanted to play around with it a little bit and pull the data into R. I’ll start by getting data from the American Community Survey Topline API for a 10km area around where I live. First some setup code here. It imports a couple libraries

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