In connection with the Le Monde puzzle of last week, I was looking for an R function that would give me the prime factor decomposition of any integer. Such a function exists within the package schoolmath, developped by Joerg Schlarmann and Josef Wienand. It is called prime.factor and it returns the prime factors of any 
The impacts of drought depend on time-scale. On short time-scales, drought means dry soil. On long time-scales, it means dry rivers and empty reservoirs. A region may simultaneously experience dry conditions on one time-scale and wet conditions on another e.g. wet soil but low streamflow or visa versa. Standardized Precipitation Index (SPI) is a widely
A contingency table is used in statistics to provide a tabular summary of categorical data and the cells in the table are the number of occassions that a particular combination of variables occur together in a set of data. The relationship between variables in a contingency table are often investigated using Chi-squared tests. The simplest contingency
At the Edinburgh mixture estimation workshop, Murray Aitkin presented his proposal to compare models via the posterior distribution of the likelihood ratio. As already commented in a post last July, the positive aspect of looking at this quantity rather than at the Bayes factor is that the priors are then allowed to be improper if 
The R package oro.nifti has been released. Medical imaging data, in NIfTI or Analyze formats, may be input, created from scratch, converted from DICOM (using oro.dicom) and output to a file.
The R package oro.nifti has been released. Medical imaging data, in NIfTI or Analyze formats, may be input, created from scratch, converted from DICOM (using oro.dicom) and output to a file.
InformationWeek published today a profile of Zack Urlocker, the former MySQL executive who recently joined REvolution's board: Former MySQL staffer Zack Urlocker is going to try to do for predictive analytics what he once did for relational database systems: bring open source code to a user population that hasn't necessarily had access to the technology before. REvolution Computing of...
In the US, at least. Via The Consumerist: Incidentally, the US FDA doesn't publish pyramids like this any more: it's now a garish personalized 2-d triangle with stripes. But at least it doesn't make the error of dimension committed by the left-hand pyramid: that orange section is a hell of a lot larger than 74% of the volume. The...
A short while ago, I reported some discrepancies between the results produced by "lme4" and other R packages as well as Stata. Today I upgraded to the most recent version of "lme4a" and re-ran my model. The error of false convergence disappea...
On a lark, and to kill a bit of time, I was running the R fortune command looking for references to SAS. Here’s what two successive random fortunes turned up. Can there be two more antipodal opinions about the same product? I laughed out loud. > fortune(‘SAS’) There are companies whose yearly license fees to 
Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).
