Category Archives: Computation

Computers, software, programming, and other bits

Python: Pandas 0.15.0 is available

Last week, Wes McKinney gave a presentation on new features in a forthcoming release of Pandas, version 0.15.0. The big news is the inclusion of a new data type for columns in Series and DataFrame, the Categorical type. This permits the use of nominal data in analyses with Pandas now, which is a huge change, […]

New York: Strata Conference, Day 1

I’m attending the O’Reilly Strata Conference (the well-respected techical books publisher, not the blowhard TV personality). This is the east coast edition, at the Javits Convention Center in New York City. Today was tutorials day. Out of about a dozen tracks, I picked the PyData track. This was a rewarding choice. The developers of varioius […]

Nutonian’s Eureqa and Concerns of Overfitting

I’ve been using Nutonian’s Eureqa symbolic regression product extensively since early 2013. Back in late 2013, there was an article about Nutonian’s Eureqa that elicited comments. An “A.E. Bartholomew” weighed in with a comment that the title, “Nutonian raises $4M to extract ‘laws of physics’ from data”, was “hyperbolic and misleading”. That led me to […]

Evolutionary Computation, Evolvability, and Python

Funnily enough, an antievolutionist brought a recent article on evolvability to my attention. The paper, “Evolvability Is Inevitable: Increasing Evolvability without the Pressure to Adapt”, by Joel Lehman and Kenneth O. Stanley, is on PLOS One. Here’s their abstract: Why evolvability appears to have increased over evolutionary time is an important unresolved biological question. Unlike […]

Raspberry Pi: An Update on Sound

Life has been a bit demanding lately, so it has been a while since I last worked on the Raspberry Pis. I had a notion that I might dragoon the Pis into serving as compute engines for a simulation I wrote in Python, and that got me motivated to get new Raspbian images and set […]

A New Year

The Mayan apocalypse failed to appear, so I had a nice New Year’s day here in Florida. The temperature got into the 70s here, and not too breezy, so Diane and I worked on various things that all too recently would have been too hot to do comfortably. But here in the evening, I’m reflecting […]

Population Modeling in Python

One of the courses I enjoyed most in my Ph.D. program was taught by Prof. Kirk Winemiller on population dynamics. There are various collections of models in various languages out there, and multi-model population dynamic applications. But I still think that there is some utility to rolling my own. Since 2009, I’ve gotten more into […]

Pairing Raspberry Pi with Teensy++

I am looking forward to getting a Teensy++ 2.0 microcontroller board. Teensy is a low-cost, small microcontroller based on Atmel AVR technology that uses USB for the programming interface. USB can also be used by the device running the user’s programs in a variety of modes. Teensy is something that I expect to solve a […]

Raspberry Pi: More About Sound Recording

I’ve moved on to the official Raspbian release. This OS image using the hardware floating-point capabilities on board the RasPi and is noticeably faster than the Debian “squeeze” image was. It allows me to reboot when I’m powering the RasPi from my USB hub, something I couldn’t do before. I’ve also tested a total of […]

Getting to an Inexpensive Audio Datalogger

Well, I spent my Saturday morning programming a C# application for Windows Mobile 5 to periodically record audio. I was aiming to set up a data logger using the Raspberry Pi board I’ve got, but I’ve run into enough problems that I decided to look at another approach. The idea is to log acoustic data […]

Discretion is a Corporate Bad Word

Mike Dunford of “The Questionable Authority” blog relates an on-going negative experience with United Airlines. His wife is in the US military and has 15 days of leave to meet with Mike. The 15 days began when her flight arrived from Afghanistan in the USA. However, her connecting flight on United Airlines was cancelled due […]

FreeBSD: Good-bye, md5crypt

The author of “md5crypt” considers it no longer safe for use in password encryption. This affects various *BSD systems, including FreeBSD, since md5crypt was long the default encryption applied to passwords in the system. Now, though, md5crypt is susceptible to brute-force attacks using GPU hardware that makes breaking an 8-character password something that can be […]

Raspberry Pi First Run

I checked the UPS tracking number periodically today. My Raspberry Pi was marked as delivered at about 2:30 today. When I got home, I found the package. I still needed to prepare the SD card, so I brought up the RasPi Wiki instructions for SD card setup and went with the Debian Squeeze distribution to […]

Raspberry Pi On Its Way

I got email from Newark today saying that they had shipped my Raspberry Pi. I should get it this week. They also sent an invoice, having charged my credit card. The item itself is $35.00, shipping is $5.00, and tax is $2.28, for a total of $42.28. Way back in early March, I called Newark […]

Python and the STFT

I’ve been going through biosonar data and while the SciPy specgram method is serviceable, I was interested in a short-time Fourier transform (STFT) implementation. There are a couple of ad hoc routines on Stack Overflow and the like, but I’ve started off with the Google Code PyTFD module. There are others out there as well, […]

Raspberry Pi: The Shopping List

I ordered a Raspberry Pi Model B computer from Newark, so now I’m waiting for stock to catch up with the truly phenomenal initial demand. If you are wondering what the Raspberry Pi is, it is a small computer board based on a Broadcom System On Chip (SoC). The SoC is ARM-based, so the operating […]

Updating the Modular CV

Some time ago, I wrote about making a modular curriculum vitae in $latex \LaTeX$. Since that time, I’ve had to update the contents. Things change. Colleagues request current CVs to include in grant proposals, and given the current state of public sector employment it is no bad thing to have the CV ready to go. […]

Losing Revenue?

Have a look at this article on the BBC site. There’s just so much wrong. The mobile telephony companies are toting up projections of profit from SMS and MMS messaging and seeing a shortfall as a “loss”. “I think it’s a growing threat which is manageable through the right tariffs and the right costing,” Mr […]