2079 search results for "ggplot"

Setting Up and Customizing R

March 7, 2012
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For the longest time I resisted customizing R for my particular environment. My philosophy has been that each R script for each separate analysis I do should be self contained such that I can rerun the script from top to bottom on any machine and get the same results. This being said, I have now

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Why an inverse-Wishart prior may not be such a good idea

March 7, 2012
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Why an inverse-Wishart prior may not be such a good idea

While playing around with Bayesian methods for random effects models, it occured to me that inverse-Wishart priors can really bite you in the bum. Inverse Wishart-priors are popular priors over covariance functions. People like them priors because they are conjugate to a Gaussian likelihood, i.e, if you have data with each : so that the

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Recovering Marginal Effects and Standard Errors from Interaction Terms in R

March 5, 2012
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When I fit models with interactions, I often want to recover not only the interaction effect but also the marginal effect (the main effect + the interaction) and of course the standard errors. There are a couple of ways to do this in R but I ended writ...

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Recovering Marginal Effects and Standard Errors from Interaction Terms in R

March 5, 2012
By

When I fit models with interactions, I often want to recover not only the interaction effect but also the marginal effect (the main effect + the interaction) and of course the standard errors. There are a couple of ways to do this in R but I ended writ...

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Recovering Marginal Effects and Standard Errors from Interaction Terms in R

March 5, 2012
By

When I fit models with interactions, I often want to recover not only the interaction effect but also the marginal effect (the main effect + the interaction) and of course the standard errors. There are a couple of ways to do this in R but I ended writ...

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Airline Fares Decreasing Steadily

March 5, 2012
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Airline Fares Decreasing Steadily

Description: Yearly average airline fare since 1995. Data: http://www.bts.gov/ Analysis: When taking the average price of domestic airline fares, there is a clear trend indicating that flying is becoming more affordable - when adjusted for infl...

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Benford’s Law and fraud in the Russian election

March 5, 2012
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Benford’s Law and fraud in the Russian election

Earlier today Ben Goldacre posted about using Benford’s Law to try and detect fraud in the Russian elections. Read that now, or the rest of this post won’t make sense. This is a loose R translation of Ben’s Stata code. The data is held in a Google doc. While it is possible to directly retrieve

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Boxplots and Day of Week Effects

March 4, 2012
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Boxplots and Day of Week Effects

THIS BLOG DOES NOT CONSTITUTE INVESTMENT ADVICE. ACTING ON IT WILL MOST LIKELY BE DETRIMENTAL TO YOUR FINANCIAL HEALTH.After following some R-related quant finance blogs like Timely Portfolio, Systematic Investor or Quantitative tho...

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Interpretation of R-index

March 4, 2012
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Interpretation of R-index

Having introduced the R-index, it is time to look how it works. For this a simple example is sufficient. What happens if a product is different from another product. To make this at least slightly realistic, three products are needed. Two products will...

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Visualization series: Insight from Cleveland and Tufte on plotting numeric data by groups

March 4, 2012
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Visualization series: Insight from Cleveland and Tufte on plotting numeric data by groups

After my post on making dotplots with concise code using plyr and ggplot, I got an email from my dad who practices immigration law and runs a website with a variety of immigration resources and tools.  He pointed out that the … Continue reading →

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