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

Change fonts in ggplot2, and create xkcd style graphs

February 17, 2013
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Change fonts in ggplot2, and create xkcd style graphs

Installing and changing fonts in your plots comes now easy with the extrafonts-package. There is a excellent tutorial on the extrafonts github site, still I will shortly demonstrate how it worked for me. First, install the package and load it. You can now install the desired system fonts (at the moment only TrueType fonts): The

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Version 1.0 of multilevelPSA Available on CRAN

February 14, 2013
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Version 1.0 of multilevelPSA Available on CRAN

Version 1.0 of multilevelPSA has been released to CRAN. The multilevelPSA package provides functions to estimate and visualize propensity score models with multilevel, or clustered, data. The graphics are an extension of PSAgraphics package by Helmreich and Pruzek. The example below will investigate the differences between private and public school internationally using the Programme of International Student Assessment...

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PID Control-R

February 8, 2013
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PID Control-R

On a whim, I thought it might be fun to try to implement a PID control algorithm ... in R.Yes, I know I have a strange idea of fun.BackgroundPID control is a heuristic method of automatically controlling processes as wide ranging as water levels in tan...

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Extracting the Epidemic Model: Going Beyond Florence Nightingale Part II

February 7, 2013
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Extracting the Epidemic Model: Going Beyond Florence Nightingale Part II

This is the second of a two part reexamination of Florence Nightingale's data visualization based on her innovative cam diagrams (my term) shown in Figure 1. Figure 1. Nightingale's original cam diagrams (click to enlarge)RecapIn Part I, I showed that FN applied sectoral areas, rather than a pie chart or...

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Why cost and fuel efficiency are unrelated: Uncorrelated manifest variables can share the same latent causes

February 7, 2013
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Why cost and fuel efficiency are unrelated: Uncorrelated manifest variables can share the same latent causes

In structural equation modelling, we are typically proposing theoretical causes of observed phenomena. These are termed "latent" (the unobserved causes) and manifest (the observed variables we measure, otherwise known as data).Importantly, the theoretical causes of behavior need not have a structure remotely resembling the correlations observed in the data. You might have hundreds of columns of...

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Modelling memory and news trajectories

February 6, 2013
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Modelling memory and news trajectories

Modelling memory In the text below I present two models I've made to quantify and visualise the diverging trajectories of memory and news events, and conclude that linear regression may be used to test which model best describes the story. First, though, I contextualise this with an illustration from the...

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Learning RStudio for R Statistical Computing

February 5, 2013
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Learning RStudio for R Statistical Computing

"Learning RStudio for R Statistical Computing" will teach you how to quickly and efficiently create and manage statistical analysis projects, import data, develop R scripts, and generate reports and graphics. R developers will learn about package development, coding principles, and … Continue reading →

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Natura non facit saltus

February 5, 2013
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Natura non facit saltus

(see John Wilkins’ article on the – interesting – history of that phrase http://scienceblogs.com/evolvingthoughts/…). We will see, this week in class, several smoothing techniques, for insurance ratemaking. As a starting point, assume that we do not want to use segmentation techniques: everyone will pay exactly the same price. no segmentation of the premium And that price should be related to...

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Relearn boxplot and label the outliers

February 5, 2013
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Relearn boxplot and label the outliers

Despite the fact that box plot is used almost every where and taught at undergraduate statistic classes, I recently had to re-learn the box plot in order to know how to label the outliers.This stackoverflow post was where I found how...

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Proposed techniques for communicating the amount of information contained in a statistical result

February 5, 2013
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Proposed techniques for communicating the amount of information contained in a statistical result

A couple of weeks ago, I posted about how much we can expect to learn about the state of the world on the basis of a statistical significance test. One way of framing this question is: if we’re trying to come to scientific conclusions on the basis of statistical results, how much can we update

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