908 search results for "how to import image file to R"

Management of Research Data – a Shell+Python+Excel+R Approach

January 23, 2013
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Management of Research Data – a Shell+Python+Excel+R Approach

I am a computer science researcher, usually working on both Windows and Linux system. Windows is the place where I do the document work, like reading paper, browsing the internet, writing papers with LaTex… Linux is where I run and generate experimental results. The Chaos After years of messy data management and recent data chaos,

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Going Beyond Florence Nightingale’s Data Diagram: Did Flo Blow It with Wedges?

January 23, 2013
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Going Beyond Florence Nightingale’s Data Diagram: Did Flo Blow It with Wedges?

In 2010, I wrote a short blog item about Florence Nightingale the statistician, solely because of its novelty value. I didn't even bother to look closely at the associated graphic she designed, but that's what I intend to do here. In this first installment, I reflect on her famous data visualization by reconstructing it...

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Reducing Respondent Burden: Item Sampling

January 22, 2013
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Reducing Respondent Burden: Item Sampling

You received confirmation this morning.  Someone made a mistake programming that battery of satisfaction ratings on your online survey.  Instead of each respondent rating all 12 items using a random rotation, only six randomly selected i...

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Data fishing: R and XML part 2

January 21, 2013
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Data fishing: R and XML part 2

I’m constantly amazed at what can be done using free software, such as R, and more importantly, what can be done with data that are available on the internet. In an earlier post, I confessed to my sedentary lifestyle immersed in code, so my opinion regarding the utility of open-source software is perhaps biased. None

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Looking to boxplots (Shootout 2012)

January 20, 2013
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Looking to boxplots (Shootout 2012)

Boxplots are a nice way to compare the three sample sets of the Shoot-out 2012 data files.There is a category variable (Set) in the data frame with the labels (Cal = Training Set, Test = Test Set and Val = Validation Set). # IMPORTING THE SAMPLE SETS #...

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texreg: A package for beautiful and easily customizable LaTeX regression tables from R

January 20, 2013
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texreg: A package for beautiful and easily customizable LaTeX regression tables from R

There was a very informative post last week showing how the R package stargazer is used to generate nice LaTeX tables from a number of R objects. This package looks very useful. However, I would like to extol the virtues of another R package that converts model objects in R into LaTeX code: texreg. For

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A slightly different introduction to R, part I

January 19, 2013
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A slightly different introduction to R, part I

Note in Swedish: Jag hoppas läsaren ursäktar att jag skriver på engelska då och då. This will be a brief introduction to using the statistics software R for biologists who want to do some of their data analysis in R. There are plenty of introductions to R (see here and here, for example; these are

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How much can we learn from an empirical result? A Bayesian approach to power analysis and the implications for pre-registration.

January 18, 2013
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How much can we learn from an empirical result? A Bayesian approach to power analysis and the implications for pre-registration.

Just like a lot of political science departments, here at Rice a group of faculty and students meet each week to discuss new research in political methodology. This week, we read a new symposium in Political Analysis about the pre-registration of studies in political science. To briefly summarize, several researchers argued that political scientists should

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Visually Comparing Return Distributions

January 18, 2013
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Visually Comparing Return Distributions

Here is a spot of code to create a series of small multiples for comparing return distributions. You may have spotted this in a presentation I posted about earlier, but I’ve been using it here and there and am finally satisfied that it is a generally useful view, so I functionalized it. When visually comparing

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Power Calculations – relationship between test power, effect size and sample size

January 17, 2013
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Power Calculations – relationship between test power, effect size and sample size

I was interested in modeling the relationship between the power and sample size, while holding the significance level constant (p = 0.05) , for the common two-sample t-Test. Luckily R has great support for power analysis and I found the function I was looking for in the package pwr. To calculate the power for the two-sample T-test

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