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...
397 search results for "sql"
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...
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...
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 
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
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...
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...
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...
Programming Language Popularity: StackOverflow and Ohloh
In the following example, programming language popularity is measured based upon two data sets. The first is the number of contributors associated with a language on ohloh.net. The second is tag usage at stackoverflow.c...
Handling Large CSV Files in R
A follow-up of my previous post Excellent Free CSV Splitter. I asked a question at LinkedIn about how to handle large CSV files in R / Matlab. Specifically,
Quotation
suppose I have a large CSV file with over 30 million number of rows, both Matlab / R lacks memory when importing the data. Could you...
Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).
