Long time no see ...Today I pushed the cpumemlog script to GitHub https://github.com/gregorgorjanc/cpumemlog. Read more about this useful utility at the GitHub site. [Read more...]

Are you using R for data manipulation for later use with other programs, i.e., a workflow something like this:read data sets from a disk,modify the data, andwrite it back to a disk.All fine, but of data set is really big, then you will soon stumble on ... [Read more...]

R can be used also as a scripting tool. We just need to add shebang in the first line of a file (script):#!/usr/bin/Rscriptand then the R code should follow.Often we want to pass arguments to such a script, which can be collected in the script by ... [Read more...]

Lots of short videos on how to do several things in R. [Read more...]

Pedigree based mixed models (often called animal models, due to modelling animal performance) are the cornerstone of animal breeding and quantitative genetics. There are many programs that can be used for analyzing your data with these models, e.g., ASREML, BLUPf90, MATVEC, MiXBLUP & MiX99,  SurvivalKit, PEST/VCE, WOMBAT, ...). There are ... [Read more...]

Linear regression is one of the key concepts in statistics [wikipedia1, wikipedia2]. However, people are often confuse the meaning of parameters of linear regression - the intercept tells us the average value of y at x=0, while the slope tells us how m... [Read more...]

Shirin Amiri was asking about GBLUP (genomic BLUP) and based on her example I set up the following R script to show how GBLUP works. Note that this is the so called marker model, where we estimate allele substitution effects of the markers and not individual based model, where genomic ... [Read more...]

While reading UseR conference abstracts I came across this sentence: "Sugarcane is polypoid, i.e., has 8 to 14 copies of every chromosome, with individual alleles in varying numbers." Vau! This generates really complex genotype system. Say we have biallelic gene with alleles being A and B. In diploids the possible genotypes ... [Read more...]

Additive genetic covariance between individuals is one of the key concepts in (quantitative) genetics. When doing the prediction of additive genetic values for pedigree members, we need the inverse of the so called numerator relationship matr... [Read more...]

gRain is an R package for "probability propagation in graphical independence networks, also known as probabilistic expert systems (which includes Bayesian networks as a special case)". This package caught my attention because some genetic models can b... [Read more...]

Here, by Charles J. Geyer. [Read more...]

R has a nice set of utilities to work with strings. Function paste is surely one among these. It can be used to "glue" several strings with optional separator. The following example shows how paste can be used to create a new variable in a dataset: dat (dat$z Today ... [Read more...]

I was testing ASReml-R program (an R package that links propriety ASReml binaries that can be used only with valid licence) this week and had to do some manipulations with the numerator relationship matrix (A). ASReml-R provides a function (asreml.Ainverse) that can create inverse of A directly from the ... [Read more...]

Jay Kerns wrote a book titled "Introduction to Probability and Statistics Using R" or IPSUR for short. He has put up a web site for the book and Rcmdr plugin. There are at least two very important points from my side (I did not read the book, yet): 1. ... [Read more...]

I have previously provided sort of an overview about plotting the pedigrees, then specifically using the Graphiviz, while I have lately used the TikZ LaTeX (see slides 11-15) system (see more example). The later gives great (beautiful) results, but at the cost of writing TikZ code - it is not ... [Read more...]

Sébastien Bihorel sent the following instructions on how to use my sweave.sh shell script in Eclipse-StatET. 1- First, you need to know the path to your TEXINPUTS settings. Type R CMD env |grep TEXINPUTS in a shell. In my installation (opensuse 11.2), the shell returned the followingTEXINPUTS=.::/usr/lib/... [Read more...]

[Read more...]

Andrej Blejec has a very nice R demo of Galton's quincunx (link1, link2). It is a bit tedious to copy the code from PDF to R console, but it is worth the effort as the demo simulation clearly shows the nature of quincunx. After a bit of search I also ... [Read more...]

Mark Heckmann writes:In your paper "Using Sweave with Lyx" (great work bty) you pointed out that one can see the sweave error code when processing when starting lyx from the terminal. I just changed from Windows to Mac so that's new for me. Could you s... [Read more...]

I am not a fan of MS Windows software. However, the reality is that majority of people use it and it is often easier for me to live with this than to convert the sorounding souls. Additionally I am find ing out lately that majority of my favourite open... [Read more...]