It seems like I have been going south since the blog started, first with the politicians and then Chennai Express. So continuing that journey, this time around I am looking at a Madras Cafe to find out what the TwitterVerse has been talking about it. Now the process is pretty ... [Read more...]

I always claim that graphs are important in econometrics and statistics ! Of course, it is usually not that simple. Let me come back to a recent experience. A got an email from Sami yesterday, sending me a graph of residuals, and asking me what could be done with a graph ... [Read more...]

This coming Tuesday, August 27, our US Chief Scientist Mario Inchosa will reveal some details of the forthcoming in-Hadoop predictive analytics capabilities of Revolution R Enterprise 7, due for release later this year. Here's the abtract of his webinar, High Performance Predictive Analytics in R and Hadoop: Hadoop is rapidly being adopted ... [Read more...]

Here's a quick update to metvurst in response to some issues encountered over the last weeks. The most important change is that the strip() function now returns the plot object rather than printing it. This means that we can work … Continue reading → [Read more...]

One critique frequently heard about Bayesian statistics is the subjectivity of the assumed prior distribution. If one is cherry-picking a prior, of course the posterior can be tweaked, especially when only few data points are at hand. For example, see the Scholarpedia article on Bayesian statistics: In the uncommon situation ... [Read more...]

I've written in a number of places about how GitHub can be a great place to store data. Unlike basically all other web data storage sites (many of which I really like such as Dataverse and FigShare) GitHub enables deep social data set development and f... [Read more...]

People love $R^2$. As such, when Nakagawa and Schielzeth published an article in the journal Methods in Ecology and Evolution earlier this year, ecologists (amid increasing use of generalized linear mixed models (GLMMs)) rejoiced. Now there’s an R function that automates $R^2$ calculations for GLMMs fit with the lme4 ... [Read more...]

Is September Bearish? Traders love discussing seasonality, and September declines in US equity markets are a favorite topic. Historically September has underperformed every other month of the year, offering a mean return of -.56% on the S&P 500 index from 1950 to 2012; 54% of Septembers were bearish over the same period – more ... [Read more...]

Usually...when I use R...I try to use it with SAP HANA as well...and the most simple way to make them work is for sure an ODBC connection....fast and simple...First, I went to my SAP HANA Studio to get the query...which is basically...get all ... [Read more...]

Importing DatesDates can be imported from character, numeric, POSIXlt, and POSIXct formats using the as.Date function from the base package.If your data were exported from Excel, they will possibly be in numeric format. Otherwise, they will m... [Read more...]

I was in (yet another) session with my analyst, "Jane", the other day, and quite unintentionally the conversation turned, once again, to the subject of "semi-log" regression equations.After my previous rant to discussion with her about this matter, I've tried to stay on the straight and narrow. It's better ... [Read more...]

by Joseph Rickert The world may indeed be awash with data, however, it is not always easy to find a suitable data set when you need one. As the number of people becoming involved with R and data science increases so does the need for interesting data sets for creating ... [Read more...]

When dealing with data from high-throughput experimental platforms such as microarrays, it’s important to account for potential batch effects. A simple example: if you process all your normal tissue samples this week and your cancerous tissue samples next week, you’re in big trouble. Differences between cancer and normal ... [Read more...]

Recently, I am working on a new modeling proposal based on the competing risk and need to prototype multinomial logit models with R. There are R packages implementing multinomial logit models that I’ve tested, namely nnet and vgam. Model outputs with iris data are shown below. However, in my ... [Read more...]

Earlier this month, we looked at the trends in the job prospects for data analysts with expertise in R and SAS, by looking at the number of job postings that mention each software package. Because R's single-letter name makes it hard to search for, and because SAS is used for ... [Read more...]

What are some of the hottest areas of research in Computer Science at the moment (August 2013)? And at which universities is this research being carried out?The answers are subjective by definition, but looking at the numbers behind the Google Research... [Read more...]

A PMML package for R that exports all kinds of predictive models is available directly from CRAN.Traditionally, the pmml package offered support for the following data mining algorithms:ksvm (kernlab): Support Vector Machinesnnet: Neural Networksrpart:... [Read more...]

# I am working on creating some functions that will be capable of creating shapes and plots that look hand drawn. # I have made some progress in this goal. # In that process I have also discovered that I can make some doodles that look hand d... [Read more...]

influence.ME is an R package for detecting influential data in multilevel regression models (or, mixed effects models as they are referred to in the R community). The application of multilevel models has become common practice, but the development of diagnostic ... [Read more...]