Bicycle tyre Schwalbe Marathon Plus

The Schwalbe Marathon are remarkable tires. I think that I inadvertently rode for at least 100 kilometers (in consecutive riding sessions) with a grain of quartz embedded in the tyre.

Schwalbe Marathon Plus tire
Schwalbe Marathon Plus tire with a grain of quartz

According to a friend who regularly enrols in cycling expeditions in exotic countries, the tire is the primary choice for a world-trip because it’s so reliable.

igraph to calculate the internal PageRank of websites

plot graph website for SEO analysis
Graph of an ecommerce website where the nodes are webpages and the edges, links between them
Analysing websites internal linking is key to understand their architecture of information and web structure and thus their potential of Search Engine Optimization, SEO.

Graphs are made of nodes and edges. In SEO nodes are webpages and edges, links directed to them from other webpages on the graph.

library(igraph)
dat=read.csv(file.choose(),header=TRUE) # choose an edgelist in .csv file format
g=graph.data.frame(dat,directed=TRUE)
transitivity(g)

Transitivity or clustering coefficient is the probability that the adjacent vertices of a vertex are connected.

Count vertices vcount(graph)
Count edges ecount(graph)

Diameter
diameter(graph)
The diameter of a graph is the length of the longest geodesic.

Graph density
graph.density(graph)
The density of a graph is the ratio of the number of edges and the number of possible edges.

Find more about plotting directed graphs here.

Most hated videos

YouTube hosts videos that are, on average, popular. This translates into high numbers of views and “I like this” clicks.
Usually there is a small number of “I dislike this”.

easyJet Hold Luggage Allowances Explained

On Feb 8th 2015 it had been viewed 84373 times, liked 12 times and disliked 26 on YouTube, that is more than 2 times as many!

The reason is simple: the video is featured on an Easyjet support page. Instead of containing instructions of travel planning, the video is a piece of corporate propaganda.

Disconnected notes from an amnesiac