Rcrastinate: 2014

Stay on track: Plotting GPS tracks with R

Many GPS devices and apps have the capability to track your current position via GPS. If you go walking, running, cycling, flying or driving, you can take a look at your exact route and your average speed.

Some of these devices or apps also allow you to export your routes in various formats, e.g., the popular XML-based GPX format.

I want to show you my attempts to

- read in a GPX file using R and its XML package,

- calculate distances and speeds between points,

- plot elevation and speed,

- plot a track,

- plot a track on a map.

Here are the results. Everything below the plots shows you how to do it in R. Drop me a comment if you have any questions.

The altitude of the track in time, with smoother. Click to enlarge.

The speed during the run, with smoother. Click to enlarge.

Aug

Getting emotional in the absence of something: Using the Berlin Affective Word List to analyze emotional valence and arousal for nouns and adjectives.

This is something I did a while ago using the Berlin Affective Word List (BAWL).

The BAWL contains ratings for 2902 German words (2107 nouns, 504 verbs, 291 adjectives). Ratings were collected for emotional valence (bad vs. good), arousal (the grade of valence) and imaginability (how well you can imagine the specific word). Please note, that I cannot supply the BAWL here on my blog. You can get the password for the Excel file, however, if you write an e-mail to Melissa Võ.

Mar

Hyperthreading FTW? Testing parallelization performance in R.

Alright, let's test some parallelization functionalities in R.

The machine:

MacBook Air (mid-2013) with 8 GB of RAM and the i7 CPU (Intel i7 Haswell 4650U). This CPU is hyper-threaded, meaning (at least that's my understanding of it) that it has two physical cores but can run up to four threads.

The task:

Draw a number of cases from a normal distribution with a mean of 10 and a standard deviation of 30. Do this a hundred times and combine the result in one vector.