Lyapunov Exponent of Logistic Map

Calculating the Lyapunov Exponent of a Time Series (with python code)

(In a later post I discuss a cleaner way to calculate the Lyapunov exponent for maps and particularly the logistic map, along with Mathematica code.) I found this method during my Masters while recreating the results of an interesting paper on how some standard tests for chaos fail to distinguish chaos from stochasticity (Stochastic neural network …

Continue reading Calculating the Lyapunov Exponent of a Time Series (with python code)

Target Distribution in Gnuplot

R code for multivariate random-walk Metropolis sampling

I couldn't find a simple R code for random-walk Metropolis sampling (the symmetric proposal version of Metropolis Hastings sampling) from a multivariate target distribution in arbitrary dimensions, so I wrote one. This is also my first R code. It requires the package MASS to sample from the multivariate normal proposal distribution using the mvrnorm function. …

Continue reading R code for multivariate random-walk Metropolis sampling

Partners meet halfway: a simple correlation study of an undergrad lab class

Last semester I taught two classes of an Introductory Physics (Electrodynamics) for Engineers lab course at the University of Texas at Austin. The first day that my students came in, most of them did not know each other. They just came in and sat at tables of two, and this pretty much became their permanent …

Continue reading Partners meet halfway: a simple correlation study of an undergrad lab class

A/B and Rh Antigens in Blood Types: A Statistical Test of Independence among IISER Kolkata Students

A couple of days ago one of my juniors in college (Indian Institute of Science Education and Research, Kolkata) found unguarded in the guest account of our computing system a spreadsheet. This spreadsheet contained the blood types of the Masters students across five batches (‘07-‘13). With this information he made a nice little bar diagram …

Continue reading A/B and Rh Antigens in Blood Types: A Statistical Test of Independence among IISER Kolkata Students

A Statistical Problem on Laptop Uptimes

Suppose you are in a large university campus. Most students here use laptops, and if you look around, you’d see most of them either working, listening to music or doing something else on their laptops. Suppose now you think of a quick project, of listing the uptimes of the laptops (how long they’ve been running). …

Continue reading A Statistical Problem on Laptop Uptimes