2723 search results for "GIS"

Making Data Visually Appealing

December 16, 2012
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Making Data Visually Appealing

I’ve recently been considering the graphical presentation of data. I get the feeling that we, ecologists/scientsits, could be better at data presentation. Graphs must be informative, but they don’t have to be ugly. I think that making visually appealing charts … Continue reading →

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Text analysis made too easy with the tm package

December 15, 2012
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Text analysis made too easy with the tm package

Today’s Gist takes the CNN transcript of the Denver Presidential Debate, converts paragraphs into a document-term matrix, and does the absolute most basic form of text analysis: a raw word count. There are actually quite a few steps in this proc...

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What is Correctness for Statistical Software?

December 14, 2012
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What is Correctness for Statistical Software?

Introduction A few months ago, Drew Conway and I gave a webcast that tried to teach people about the basic principles behind linear and logistic regression. To illustrate logistic regression, we worked through a series of progressively more complex spam detection problems. The simplest data set we used was the following: This data set has

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Everything is a Network, featuring the sna package

December 14, 2012
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Everything is a Network, featuring the sna package

We’ve gotten some requests, through the Ask us anything page, to do some plotting of networks. We may come back to this later, but today’s Gist shows how you can plot pretty much literally anything as a network. First, we go back to our

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Mapping GPS Tracks in R

December 13, 2012
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Mapping GPS Tracks in R

This is an explanation of how I used R to combine all my GPS cycling tracks from my Garmin Forerunner 305.Converting to CSVYou can convert pretty much any GPS data to .csv by using GPSBabel. For importing directly from my Garmin, I used the comman...

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Fuzzy clustering with fanny()

December 13, 2012
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Fuzzy clustering with fanny()

This is kind of a fun example, and you might find the fuzzy clustering technique useful, as I have, for exploratory data analysis. In this Gist, I use the unparalleled breakfast dataset from the smacof package, derive dissimilarities from breakfast it...

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Is invasive?

December 13, 2012
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Is invasive?

The Global Invasive Species Database (GISD) (see their website for more info here) has data on the invasiveness status of many species. From taxize you can now query the GISD database. Introducing the function gisd_isinvasive. This function was contributed to taxize by Ignasi Bartomeus, a postdoc at the Swedish University Agricultural Sciences. There are two possible outputs from using...

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Is invasive?

December 13, 2012
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Is invasive?

The Global Invasive Species Database (GISD) (see their website for more info here) has data on the invasiveness status of many species. From taxize you can now query the GISD database. Introducing the function gisd_isinvasive. This function was contributed to taxize by Ignasi Bartomeus, a postdoc at the Swedish University Agricultural Sciences. There are two possible outputs from using...

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Multidimensional metric unfolding with SMACOF

December 12, 2012
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Multidimensional metric unfolding with SMACOF

SMACOF stands for “Scaling by MAjorizing a COmplicated Function,” and it is a multidimensional scaling algorithm for metric unfolding of, among other things, rectangular ratings matrices. One neat Political Science application of MDS is i...

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Multidimensional scaling of REM album covers: FlagSpace revisited

December 11, 2012
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Multidimensional scaling of REM album covers: FlagSpace revisited

By way of following up on an old in-joke, and doing something constructive because I couldn’t get to sleep, I thought I would revisit the Flag Space plot that I blogged about a while back and learn how to do it. … Continue reading →

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