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

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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If SPSS can factor analyze MaxDiff scores, why can’t R?

January 17, 2013
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If SPSS can factor analyze MaxDiff scores, why can’t R?

Answer:  The variance-covariance matrix containing all the MaxDiff scores is not invertible.  R tells you that, either with an error message or a warning.  SPSS, at least earlier versions still in use, runs the factor analysis witho...

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Creating a random calendar with R

January 14, 2013
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Creating a random calendar with R

Sometimes this is my life. But it’s so satisfying when you write a program that saves you time! Here is an example. The Problem:  For several years at Hopkins I have been involved in teaching a large (500+ person) introductory Biostatistics class. This … Continue reading →

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Using TeXmacs as an interface for R

January 14, 2013
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Using TeXmacs as an interface for R

Using TeXmacs as an interface for R (part 1)(This post was copied from my post at wordpress. Because I didn't manage to switch r-bloggers.com to use that blog, I'm reposting it here....) A nice, but not very well known, interface to R isTeXmacs. (I...

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