562 search results for "SQL"

BLAS, BLASter, BLAStest: Some benchmark results, and a benchmarking framework

September 15, 2010
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BLAS, BLASter, BLAStest: Some benchmark results, and a benchmarking framework

Usage of accelerated BLAS libraries seems to shrouded in some mystery, judging from somewhat regularly recurring requests for help on lists such as r-sig-hpc (gmane version), the R list dedicated to High-Performance Computing. Yet it doesn't have to be...

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SyntaxHighlighter Brush for the R Language

September 11, 2010
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al Galili requested in the R-help mailing list for a SyntaxHighlighter brush for the R language, so that WordPress users can highlight their R code easily. I promised to contribute a few minutes on this task, and here is the result: /** * Author: Yihui Xie * URL: http://yihui.name/en/2010/09/syntaxhighlighter-brush-for-the-r-language * License: GPL-2 | GPL-3 */

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plyr and reshape: better, faster, more productive

September 10, 2010
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Hadley Wickham has just released updates to his data-manipulation packages for R, plyr and reshape (now called reshape2), that are much faster and more memory-efficient than the previous incarnations. The reshape2 package lets you flexibly restructure and aggregate data using just three functions (melt, acast and dcast), whereas the plyr package is kind of like a supercharged SQL "GROUP...

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Bot Botany – K-Means and ggplot2

September 2, 2010
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Bot Botany – K-Means and ggplot2

So if you had a robot that was an expert at botany - would you have a bot botanist?  Among other things, it would need to to distinguish flowers through vision and image processing, and be able to classify various kinds of plants based upon specif...

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Bot Botany – K-Means and ggplot2

September 2, 2010
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Bot Botany – K-Means and ggplot2

So if you had a robot that was an expert at botany - would you have a bot botanist?  Among other things, it would need to to distinguish flowers through vision and image processing, and be able to classify various kinds of plants based upon specif...

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GEO database: curation lagging behind submission?

August 30, 2010
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GEO database: curation lagging behind submission?

I was reading an old post that describes GEOmetadb, a downloadable database containing metadata from the GEO database. We had a brief discussion in the comments about the growth in GSE records (user-submitted) versus GDS records (curated datasets) over time. Below, some quick and dirty R code to examine the issue, using the Bioconductor GEOmetadb

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Producing grids of plots in R with ggplot2: A journey of discovery

August 26, 2010
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Producing grids of plots in R with ggplot2: A journey of discovery

I’ve just gone through a bit of a ‘journey of discovery’ in R while trying to plot a grid of plots for one of the research projects I’m doing. I wanted to write a simple function which could produce this grid of plots from a CSV file, allowing me to easily view the trends of

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How Safe is Your Money?

August 24, 2010
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How Safe is Your Money?

The FDIC regularly publishes a Failed Bank List and related statistics.  This post uses data in the original XLS from the FDIC web site which is formatted for human consumption to produce the charts below using R.  Note that 2010 data be...

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Using R for Introductory Statistics, Chapter 3.4

August 21, 2010
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Using R for Introductory Statistics, Chapter 3.4

...a continuing journey through Using R for Introductory Statistics, by John Verzani. Simple linear regression Linear regression is a kooky term for fitting a line to some data. This odd bit of terminology can be blamed on Sir Francis Galton, a proli...

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Using R for Introductory Statistics, Chapter 3.4

August 21, 2010
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Using R for Introductory Statistics, Chapter 3.4

...a continuing journey through Using R for Introductory Statistics, by John Verzani. Simple linear regression Linear regression is a kooky term for fitting a line to some data. This odd bit of terminology can be blamed on Sir Francis Galton, a proli...

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