Solving problems with graphs

I saw this question on Quora:

A teacher assigns each of her 18 students a different integer from 1 through 18. The teacher forms pairs of study partners by using the rule that the sum of the pair of numbers is a perfect square. Assuming the 9 pairs of students follow this rule, the student assigned which number must be paired with the student assigned the number 1?

A. 16
B. 15
C. 9
D. 8
E. 3

Continue reading

Learning R through a mini game part 3

This is my third post on learning R through the BetaBit package, which contains three mini games for learning R. I wrote about the first game, called proton, late last year and the second game, called frequon, a week and a half ago. The third game is called regression and it's much more statistical than the other two. I actually couldn't complete the last task of the game, so if you know how to approach it, please let me know!

Continue reading

Learning R through a mini game

Just last night I found this educational mini game written in R and decided to have a go at it:

I completed it but as I alluded to in my tweet, not in a very elegant manner. This post is on using the dplyr package in R to solve some of the problems. If you want to give the game a go first, then stop reading now.

Continue reading

Wordcloud of PubMed searches

At the start of this year I created a Twitter account that automatically tweets out papers related to transcriptomes, i.e. a Twitter literature bot. This idea isn't new and there are over 200 Twitter literature bots. However, I wrote my Twitter bot using R (and using the RISmed package to search PubMed for papers) and it's running on an EC2 instance, which is part of Amazon Web Services. I went with this approach simply because I wanted to try out Amazon Web Services; I will have to find another server to run my Twitter bot when my free period is over.

Continue reading

Getting started with AWS Support (Basic)

Several years ago I learned that one could sign up to the Amazon Web Services (AWS) for free. This sign up allows you to test many of their web services for free, for a year, as long as your usage is within the AWS Free Tier. To sign up to the AWS Support (Basic), you need a credit card and a phone number that you can be contacted on (I got an automated called on my phone and had to punch in a PIN to finish the registration process).

Continue reading

Transcriptome feed using R

I've always wanted to create a transcriptome feed on Twitter, posting the results of daily PubMed searches. Well today I finally got around to it. Firstly, I made a new Twitter account; annoyingly all the Twitter handles I wanted were taken by inactive users. I decided to go with @transcriptomes. Next, I made a new Twitter application that's associated with my new Twitter account (I set permissions to "Read, Write and Access direct messages"), and I set it up so that I could use twitteR to communicate with this app. For this post, I'm using OS X 10.10.1 on a MacBook Air.

Continue reading