1980 search results for "ggplot"

Varying Window Length for Linear Models on Stocks

April 24, 2012
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Varying Window Length for Linear Models on Stocks

In a previous post, we discussed ideas generated by a Timely Portfolio post about Linear Models on Stock. I wanted to see if there was a relationship between the window length of the running mean of the linear regression slope estimate and the running mean of the correlation between fitted and observed values. The parameters

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How to remember point shape codes in R

April 24, 2012
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How to remember point shape codes in R

I suspect I am not unique in not being able to remember how to control the point shapes in R. Part of this is a documentation problem: no package ever seems to write the shapes down. All packages just use the “usual set” that derives from S-Plus and was carried through base-graphics, to grid, lattice Related posts:

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Short R script to plot effect sizes (Cohen’s d) and shade overlapping area

April 23, 2012
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Short R script to plot effect sizes (Cohen’s d) and shade overlapping area

In this short post I take a look at how to use R and ggplot2 to visualize effect sizes (Cohen’s d) and how to shade the overlapping area of two distributions.

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Probit/Logit Marginal Effects in R

April 23, 2012
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Probit/Logit Marginal Effects in R

The common approach to estimating a binary dependent variable regression model is to use either the logit or probit model. Both are forms of generalized linear models (GLMs), which can be seen as modified linear regressions that allow the dependent variable to originate from non-normal distributions. The coefficients in a linear regression model are marginal

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Visualising the Path of a Genetic Algorithm

April 23, 2012
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Visualising the Path of a Genetic Algorithm

We quite regularly use genetic algorithms to optimise over the ad-hoc functions we develop when trying to solve problems in applied mathematics. However it’s a bit disconcerting to have your algorithm roam through a high dimensional solution space while not being able to picture what it’s doing or how close one solution is to another. … Continue reading...

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118 years of US State Weather Data

April 22, 2012
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118 years of US State Weather Data

A recent post on the Junkcharts blog looked at US weather dataand the importance of explaining scales (which in this case went up to 118). Ultimately, it turns out that 118 is the rank of the data compared to the previous 117 years of data (in ascending order, so that 118 is the highest). At … Continue reading...

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Generating all subsets of a set

April 20, 2012
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Generating all subsets of a set

Recently I have calculated Banzhaf power index. I required generation of all subsets of a given set. The code given there was a bit complex and I have decided to write a simple function calculating it. As an example of its application I reproduce Figur...

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An R Script to Automatically download PubMed Citation Counts By Year of Publication

April 19, 2012
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An R Script to Automatically download PubMed Citation Counts By Year of Publication

Ever wanted to look at PubMed trends and make elegant graphs of them? Here’s an R script that will do it automatically for you.

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Visualizing iOS Text Editors

April 18, 2012
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Visualizing iOS Text Editors

The other day Brett Terpstra posted a gigantic and quite beautifully-executed feature comparison of all of the text editors available for iOS devices. The table is really terrific and also a bit overwhelming, as there's so much data. On the bus home ye...

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Small Countries Stablize by Exporting High-Tech

April 18, 2012
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Small Countries Stablize by Exporting High-Tech

Smaller countries lead the way. When you think of 'high-tech', which countries come to mind? What is 'High-Tech'? Before continuing, what is meant by the term 'high-tech'? As defined by the World Data Bank, high-technology exports ar...

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