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

Color Palettes in RGB Space

June 20, 2012
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Color Palettes in RGB Space

Introduction I've recently been interested in how to communicate information using color. I don't know much about the field of Color Theory, but it's an interesting topic to me. The selection of color palettes, in particular, has been a topic I've been faced with lately. I downloaded 18 different sequential color palettes from Cynthia Brewer's

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Estimation of hydraulic conductivity and its uncertainty from grain-size data using GLUE and artificial neural networks.

June 13, 2012
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Estimation of hydraulic conductivity and its uncertainty from grain-size data using GLUE and artificial neural networks.

AbstractVarious approaches exist to relate saturated hydraulic conductivity (Ks) to grain-size data. Most methods use a single grain-size parameter and hence omit the information encompassed by the entire grain-size distribution. This study compares two data-driven modelling methods—multiple linear regression and artificial neural networks—that use the entire grain-size distribution data as input for Ks prediction. Besides the predictive capacity of the methods,...

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Finding word use patterns in Wikileaks cables

June 12, 2012
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Finding word use patterns in Wikileaks cables

6/18: A follow-up to this post is now available here.Recent DiscoveriesWhen I was a diplomat, I was always interested in the Wikileaks cables and what could be done with them. Unfortunately, I never got a chance to look at the site in depth, due to security policies. Now that the ex- is firmly prepended to diplomat...

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Finding word use patterns in Wikileaks cables

June 12, 2012
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Finding word use patterns in Wikileaks cables

6/18: A follow-up to this post is now available here.Recent DiscoveriesWhen I was a diplomat, I was always interested in the Wikileaks cables and what could be done with them. Unfortunately, I never got a chance to look at the site in depth, due to security policies. Now that the ex- is firmly prepended to diplomat...

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Finding Word Use Patterns in Wikileaks Cables

June 12, 2012
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Finding Word Use Patterns in Wikileaks Cables

6/18: A follow-up to this post is now available here.Recent DiscoveriesWhen I was a diplomat, I was always interested in the Wikileaks cables and what could be done with them. Unfortunately, I never got a chance to look at the site in depth, due to security policies. Now that the ex- is firmly prepended to diplomat in my...

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Data distillation with Hadoop and R

June 11, 2012
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Data distillation with Hadoop and R

We're definitely in the age of Big Data: today, there are many more sources of data readily available to us to analyze than there were even a couple of years ago. But what about extracting useful information from novel data streams that are often noisy and minutely transactional ... aye, there's the rub. One of the great things about...

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Random regression coefficients using lme4

June 11, 2012
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Random regression coefficients using lme4

What's the gain over lm()?By Ben OgorekRandom effects models have always intrigued me. They offer the flexibility of many parameters under a single unified, cohesive and parsimonious system. But with the growing size of data sets and increased ability to estimate many parameters with a high level of accuracy, will the subtleties of the random effects analysis be lost? In this...

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Mapping the World’s Biggest Airlines

June 7, 2012
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Mapping the World’s Biggest Airlines

The map above shows the routes flown by the top 7 airli

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Simulating the Birthday Problem with data derived probabilities

June 6, 2012
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Simulating the Birthday Problem with data derived probabilities

You've probably heard of the Birthday Paradox: it only takes a small gathering of people before it's quite likely that two of them share the same birthday. You can solve the problem analytically or with simulation, but usually in either case simplifying assumptions are made (no-one born on February 29, for example). Joe Rickert uses Revolution R Enterprise 6...

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Let’s Party!

June 6, 2012
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Let’s Party!

Exploring whether regression coefficients differ between groups is an important part of applied econometric research, and particularly for research with a policy based objective. For example, a government in a developing country may decide to introduce free school lunches in an effort to improve childhood health. However, if this treatment is known to only improve

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