Monthly Archives: July 2012

Bayesian Inference Using OpenBUGS

July 22, 2012
By
Bayesian Inference Using OpenBUGS

In our previous statistics tutorials, we have treated population parameters as fixed values, and provided point estimates and confidence intervals for them. An alternative approach is the Bayesian statistics. It treats population parameters as random...

Read more »

R for Ecologists: Phylogenies in R

July 22, 2012
By
R for Ecologists: Phylogenies in R

I’ve only recently begun working from an evolutionary perspective, and I can’t imagine why I haven’t thought about it much before. After all, it comes up in just about everything that we do in ecology. For example, I’m currently feeding … Continue reading →

Read more »

London Olympics and a prediction for the 100m final

July 22, 2012
By
London Olympics and a prediction for the 100m final

It is less than a week before the 2012 Olympic games will start in London. No surprise therefore that the papers are all over it, including a lot of data and statistis around the games. The Economist investigated the potential financial impact on spons...

Read more »

Project Euler — problem 16

July 21, 2012
By

The 16th problem is another big-number problem: 215 = 32768 and the sum of its digits is 3 + 2 + 7 + 6 + 8 = 26. What is the sum of the digits of the number 21000? This … Continue reading →

Read more »

Base versus grid graphics

Base versus grid graphics

In a comment in response to my latest post, Robert Young took issue with my characterization of grid as an R graphics package. Perhaps grid is better described as a “graphics support package,” but my primary point – and the main point of this post – is that to generate the display you want, it is sometimes necessary to use commands...

Read more »

The magic of the year 1901

July 21, 2012
By
The magic of the year 1901

The year 1901 is rather magical. Well it is for R provided you run it under Linux. Let me show you why. I have four data points, one from 1900, two from 1901, and one from 1902. dates values I convert them in two different ways; as a Date, and as a POSIXct. For...

Read more »

Emulating dynamic scoping in GNU R

July 21, 2012
By

By design GNU R uses lexical scoping. Fortunately it allows for at least two ways to simulate dynamic scoping.Let us start with the example code and next analyze it:x <- "global"f1 <- function() cat("f1:", x, "\n")f2 <- function() cat("f2:", e...

Read more »

googleVis — where did SYTYCD dancers come from?

July 21, 2012
By

After watching 20 wonderful dancers of the 9th season of So You Think You Can Dance, I have presented a geomap of  the states where they are coming from (click here). Now, I am interested to this show’s history.  I’d like to re-draw the … Continue reading →

Read more »

Automatic Hyperparameter Tuning Methods

July 20, 2012
By

At MSR this week, we had two very good talks on algorithmic methods for tuning the hyperparameters of machine learning models. Selecting appropriate settings for hyperparameters is a constant problem in machine learning, which is somewhat surprising given how much expertise the machine learning community has in optimization theory. I suspect there’s interesting psychological and

Read more »

Le Monde puzzle [#783]

July 20, 2012
By
Le Monde puzzle [#783]

In a political party, there are as many cells as there are members and each member belongs to at least one cell. Each cell has five members and an arbitrary pair of cells only shares one member. How many members are there in this political party? Back to the mathematical puzzles of Le Monde (science

Read more »