It's been a year since I began keeping a web log. This post presents some thoughts related to the experience. Blogging is Sharing Ideas Blogging is online self-publishing. There is no faster way to share your ideas so broadly. Last year at the useR! conference (in Gaithersburg, MD, just a ... [Read more...]

I recently uploaded some code to R-forge related to an R package I’ve been working on, titled yarr. The work was motivated by a desire to embed R code and output within my HTML blog posts! Months ago, I wrote about a potential solution to this using the brew ... [Read more...]

Sierra Trading Post mailed me their End-of-Winter 2011 catalog, which consists mostly of mid- to high-end sportswear products, but also things like snow skis, flashlights, and binoculars. STP sells closeouts, overstock, seconds, and items with cosmetic blemishes or irregularities. I spent an hour of relaxation time enumerating the various product brands ... [Read more...]

I connected the instrumentation amplifier described in an earlier post to a piezoelectric transducer (buzzer) and made recordings at 5000 gain. The plot below shows 1000 such measurements over 1.0 seconds. There is a 4.0 second (at 1000Hz) sample of the data here piezo.csv. There is a clear sinusoidal signal in these data ... [Read more...]

In an earlier post, I described some ECG signal processing. In fact, these recordings were from my own heart, and I had collected them using a homemade ECG. The following is a repost from my old site describing the device. I assembled an instrumentation amplifier to measure cardiac potentials (i.... [Read more...]