888 search results for "how to import image file to r"

Modeling Permanent and Gradual Process Changes with CDFs

July 20, 2012
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Modeling Permanent and Gradual Process Changes with CDFs

Spencer HerathSpecial thanks to Ben OgorekBackgroundI recently faced a process with a structural change resulting in an increase in the process mean.  The jump to the new mean was not immediate; rather, there was a gradual increase in values over time.  I had previously benefited from multi-staged process-behavior charts when encountering immediate process shifts, but now I needed a...

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Time zones

July 18, 2012
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Time zones

Say we have some following raw data. It consists of a timestamp and a corresponding value. There is a peak at exactly midnight (00:00:00). Each timestamp is fully specified. It contains a date, a time of day, and a time zone offset indication. In this case +0000, meaning the data is 0 hours away the UTC timezone. "timestamp","value""25-04-2012...

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R for Ecologists: Creating a Site x Species Matrix

July 17, 2012
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R for Ecologists: Creating a Site x Species Matrix

Today I’m going to adress a fairly common problem in ecology that has been coming up frequently as of late. The issue is how to create a site x species matrix for community composition analysis (i.e. ordination). Moreover, ecologists have to do … Continue reading →

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Hierarchical Cluster Analysis (ChemoSpec) – 01

July 17, 2012
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Hierarchical Cluster Analysis (ChemoSpec) – 01

I have been in previous post using the ChemoSpec package for some oil data (olive and sunflower). My spectra has now a range from 1100nm to 2200nm and is raw (not treated mathematically) . I want to start using the ChemoSpec package to start using the ...

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Processing Public Data with R

July 13, 2012
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Processing Public Data with R

I use R aplenty in analysis and thought it might be worthwhile for some to see the typical process a relative newcomer goes through in extracting and analyzing public datasets In this instance I happen to be looking at Canadian air pollution statistics. The data I am interested in is available on the Ontario Ministry

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Using discrete-event simulation to simulate hospital processes

July 12, 2012
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Using discrete-event simulation to simulate hospital processes

Discrete-event simulation is a very useful tool when it comes to simulating alternative scenario’s for current of future business operations. Let’s take the following case; Patients of an outpatient diabetes clinic are complaining about long waiting times, this seems to have an adverse effect on patient satisfaction and patient retention.  Read more »

A Napa Valley wine tasting map, made with R and ggmap

July 9, 2012
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A Napa Valley wine tasting map, made with R and ggmap

R has had a maps package available since the very early days. It's great for simple geographic maps, but the political boundaries can be out of date. For more detailed maps, you can also download shape files and use the sp package to draw borders directly. But for accurate and attractive maps of countries, roads and satellite imagery, nothing...

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Fitting a dynamic model, and determining the number of parameters that can be fitted.

July 8, 2012
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Fitting a dynamic model, and determining the number of parameters that can be fitted.

Let's suppose that we have the same dynamic model we presented before - that is, the Lorentz system of differential equations. Remember? In order to perform a fitting we need to define an objective function of sort: this will then be minimised. Now,...

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SMS analysis (coming from an Android smartphone or an IPhone)

July 7, 2012
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SMS analysis (coming from an Android smartphone or an IPhone)

At first, this post was intended to describe how to manipulate dates with R but, as the idea was coming from the question of one of my students who wanted to analyze his SMS, I thought that I might as well also explain the whole analysis process... Using my new smartphone (that I started to

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