Discrete-event simulation is a very useful tool when it comes to simulating alternative scenario’s for current of future business operations. Let’s take the following case; Patients of an outpatient diabetes clinic are complaining about long waiting times, this seems to have an adverse effect on patient satisfaction and ... [Read more...]

In the previous post we saw how much convenient could be GenABEL in the management of genotypic/phenotypic data. We introduced the import of genotypic data from an Illumina format file: __ convert.snp.illumina(inf = "gen.illu", out = "gen.raw", strand = "file") … Continue reading → [Read more...]

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In case you missed them, here are some articles from June of particular interest to R users. The FDA goes on the record that it's OK to use R for drug trials. A review of talks at the useR! 2012 conference. Using the negative binomial distribution to convert monthly fecundity into ... [Read more...]

Many public agencies release data in a fixed-format ASCII (FWF) format. But with the data all packed together without separators, you need a "data dictionary" defining the column widths (and metadata about the variables) to make sense of them. Unfortunately, many agencies make such information available only as a SAS ... [Read more...]

Lets go one with the second part of learning R by doing R (you will find the first part here. As we have used vectors, matrices and loops in the first part, we will concentrate on graphics in this one. but first we will need data to plot: Sometimes you ... [Read more...]

[This article was first published on Xi'an's Og » R, and kindly contributed to R-bloggers]. (You can report issue about the content on this page here) Want to share your [Read more...]

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The 13th in Project Euler is one big number problem: Work out the first ten digits of the sum of the following one-hundred 50-digit numbers. Obviously, there are some limits in machine representation of numbers. In R, 2^(-1074) is the smallest … Continue reading → [Read more...]

Geography is often about statistics as it is the basis for fast exchange of information: providing a mean and standard deviation to the audience is often much easier then showing raw data: Learning a script language for this purpose can be a hard-ass work. But I think it is more ... [Read more...]

R has had a maps package available since the very early days. It's great for simple geographic maps, but the political boundaries can be out of date. For more detailed maps, you can also download shape files and use the sp package to draw borders directly. But for accurate and ... [Read more...]

Besides microscopic images in our routine, common photos are frequently taken to measure quantitative plant features, such as leaf area, root length, branch numbers, etc. Scientific software is available for manual processing. For example, to measure the root length, one need to use the … Continue reading → [Read more...]

At first, this post was intended to describe how to manipulate dates with R but, as the idea was coming from the question of one of my students who wanted to analyze his SMS, I thought that I might as well also explain the whole analysis process... Using my new ... [Read more...]

This post shows how to create a timeline graph by using ggplot2. Let’s start by loading the ggplot2 library. Next let’s create a dataset which we will use to feed the graph. In the last column (y), I create random positive values for the first three rows (which ... [Read more...]

Welcome to this demo of how R code and results can be combined into an HTML report. This entire blogpost was generated by using a combination of R, knitr and markdown. Beforehand, make sure you have the following libraries installed (latest version); knitr markdown ggplot2 (to run the example script)  ... [Read more...]

Going to supper in 20 minutes. I’d like to type down my solution to the 12th Euler problem, just make my time count. The sequence of triangle numbers is generated by adding the natural numbers. So the 7th triangle number … Continue reading → [Read more...]

The biggest prize in UK soccer, the Premier League Championship, is decided by a points system. Unlike most sports competitions, there's no final round or playoff series: once the regular round of games is complete, the team that has accumulated the most points (three for a win, and one for ... [Read more...]

The caret package for R provides a variety of error metrics for regression models and 2-class classification models, but only calculates Accuracy and Kappa for multi-class models.  Therefore, I wrote the following function to allow caret:::train t... [Read more...]

Counting cells under microscope is always laborious and null. Those in the art would be relieved with assistance of a powerful image processing package, EBImage. Images are treated as “Image” objects, essentially multi-dimensional arrays. The class “Image” contains spatial information, pixel … Continue reading → [Read more...]

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