2729 search results for "GIS"

Reproducible reports & research with knitr in R Studio

June 18, 2012
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Reproducible reports & research with knitr in R Studio

Arguably, knitr (CRAN link) is the most outstanding R package of this year and its creator, Yihui Xie is the star of the useR! conference 2012. This is because the ease of use comparing to Sweave for making reproducible report. Integration of knitR and R Studio has made reproducible research much more convenience, intuitive and easier to

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Example 9.35: Discrete randomization and formatted output

June 18, 2012
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Example 9.35: Discrete randomization and formatted output

A colleague asked for help with randomly choosing a kid within a family. This is for a trial in which families are recruited at well-child visits, but in each family only one of the children having a well-child visit that day can be in the study. The idea is that after recruiting the family, the research assistant...

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Tracking US Sentiments Over Time In Wikileaks

June 18, 2012
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Tracking US Sentiments Over Time In Wikileaks

Introduction I recently posted about using the Wikileaks cable corpus to find word use patterns, both over time, and in secret cables vs unclassified cables. I received a lot of good suggestions for further topics to pursue with the corpus, and probably the most interesting was the idea to do sentiment analysis over time on a variety of...

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Comparing performance in R, foreach/doSNOW, SAS, and NumPY (MKL)

June 17, 2012
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This is a follow up to my previous post.  There is a quicker way to compute the function I created (basic cumulative sum) in R.Instead of:function f(x) {   sum = 0;   for (i in seq(1,x)) sum = sum + i   return(su...

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Cubism Horizon Charts in R

June 15, 2012
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Cubism Horizon Charts in R

Like many, I have been in awe of the d3.js and cubism.js visualization packages created by Mike Bostock. Mike Bostock @ Square talks about Time Series Visualization from Librato on Vimeo. The charts are beautiful and extraordinarily functional, so I th...

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Pretty Correlation Map of PIMCO Funds

June 14, 2012
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Pretty Correlation Map of PIMCO Funds

As PIMCO expands beyond fixed income, I thought it might be helpful to look at correlation of PIMCO mutual funds to the S&P 500.  Unfortunately due to the large number of funds, I cannot use the chart.Correlation from PerformanceAnalytics.&nbs...

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Mindoro Digital Elevation Map

June 14, 2012
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Mindoro Digital Elevation Map

Saw a map produced by my previous student using a commercial GIS software.Using R raster package and data from diva-gis.org. I produced the same map

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#4 R: A powerful tool for the geochemist

June 14, 2012
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#4 R: A powerful tool for the geochemist

  R is an incredibly powerful programming tool used by a large community of people who require an easy to use, light weight, FREE, and fundamentally awesome statistics package! I have recently discovered that R can be used by geologists whose IT skills are often pitied by their more computer literate geophysicist colleagues. Long story short

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Revolution Newsletter: June 2012

June 14, 2012
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The most recent edition of the Revolution Newsletter is out. The news section is below, and you can read the full June edition (with highlights from this blog and community events) online. You can subscribe to the Revolution Newsletter to get it monthly via email. Revolution R Enterprise 6 Now Available! The latest release of Revolution R Enterprise brings...

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Performance with foreach, doSNOW, and snowfall

June 13, 2012
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Is it just me, or does the performance of the foreach package with a doSNOW backend operating on a socket grid suck?Here at work, I am helping to setup a cluster of Windows machines for distributed R processing.  We have lots of researchers runnin...

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