Last week we have downloaded and loaded into R data from fitness tracker (motion coprocessor in iphone). Then with just few lines of R code we decomposed the data into a seasonal weekly component and the trend. Today we are going to see how to plot the number of steps per hour for different days of week. And then same data will be used to check how often there was any activity at given time.
During the Christmas break I met my brother-in-law who is an ultimate gadgeteer (an excellent trait for brother). He told me that most iPhones have build-in motion coprocessor and by default they are counting steps. No need to turn on anything, it is working all the time (assuming that the phone is with you).
The new version of the ggplot2 package (v 2.0.0) will be available on CRAN in a few days.
It has a very nice mechanism for adding new geoms and stats.
I’ve prepared a short console-based data-driven R game named ,,The Proton Game’’ or ,,Hack the Proton” (still cannot decide which name is better). The goal of a player is to play the hacker and infiltrate Slawomir Pietraszko’s account on a Proton server. To do this, you have to solve four data-based puzzles.
Decision trees are cute.
It is easy to visualize them, easy to explain, easy to apply and even easy to construct.
Unfortunately they are quite unstable, particularly for large sets of correlated features.
Today we are going to illustrate some subtle differences among three statistical packages, R/SAS/SPSS. Small differences, but sometimes even a very small difference may have large consequences. So it is worth to know such things.
Two days ago Hadley Wickham tweeted a link with introduction to his new package multidplyr. Basically it’s a tool to take advantage of many cores for dplyr operations. Let’s see how to play with it.
7th term of the Sejm has already come to its end. It would be nice to see how have the Members of Polish Parliament voted for these last 4 years! In total they took part in over 6000 votings. Did the representatives of the same clubs voted more similarly to each other? Did the Members of Polish Parliament who changed the clubs they belonged to voted in a different way than the Members of Parliament from their former clubs? Let’s see!
Some time ago our herd has expanded by a guinea pig called Hugo. It turns out that the presence of a pet at home is a great pretext for discussing with children the concepts of randomness, distribution functions and distribution in general.
Children bring from school strange home assignments, like for example a question: What is your dad’s job similar to? After several hits (a cosmonaut, Formula 1 driver, firefighter) it turns out that the work performed by a statistician is very much similar to the work of a shoemaker. Why?