Maybe you remember playing this one as a kid. If you are about my age, you may have even created a version of this game as one of your first computer programs. You guess a number, the computer tells you if you if you are too low or high. I’... [Read more...]
I woke up from my afternoon nap feeling a bit off-kilter, so I decided to go for another random walk. In particular, I wanted a journey that avoided the center, but didn’t just run for an exit either. After playing around for a while I came up with this: # ... [Read more...]
It’s 1943 and you work for the good guys. A handful of German tanks have been captured, and each one has a serial number. This is back when serial numbers were still presumed to come in serial, one right after the other. Given your collection of numbered tanks, and assuming ... [Read more...]
If you are used to object oriented programing in a different language, the way R does things can seem a little strange and backwards. “proto” to the rescue. With this library you can simulate “normal” OOP. I found the examples for proto not so helpful, so to figure out how ... [Read more...]
More playing around with R. To create the graph above, I sampled 100 times from two different normal distributions, then plotted the ratio of times that the first distribution beat the second one on the y-axis. The second distribution always had a mean of 0, the mean of first distribution went from 0 ... [Read more...]
There are a few ways to do this, but the only one that worked for me was to use Rserve and rconnect. In R, do this:
Rserve(debug = FALSE, port=6311, args=NULL)
Then you can connect in Python very easily. Here is a test in ... [Read more...]
Before I decided to learn R in a serious way, I thought about learning Flash/Actionscript instead. Most of my work involves evolutionary models that take place over time. I need visual representations of change. It’s certainly possible to represent change and tell an evolving story with a single ... [Read more...]
To start sending all output to a file, do this:
sink("path/to/filename") # Direct all output to file
print("Hi there") # Will be printed to file
sink() # Turn off buffing to file
Related to this I recently had to use:
This forces your console to print out ... [Read more...]
$100 to the first person who can figure out how I created this plot and replicate it. Some hints:
It was done in R.
There is only one underlying probability distribution involved (one “rdist()“).
Including the “plot” statement, I created this with 3 short lines of code.
This is based on a ... [Read more...]
I found this interesting question over here at mathoverflow.net. Here’s the question:
If you have a country where every family will continue to have children until they get a boy, then they will stop. What is the proportion of boys to girls in the country.
First off, there ...