Blog Archives

Quicksort speed, just in time compiling and vectorizing

August 17, 2014
By
Quicksort speed, just in time compiling and vectorizing

I was reading the Julia documentation the other day. They do speed comparisons to other languages. Obviously R does not come out very well. The R code for quicksort is here and I noticed it was not vectorized at all. So I wondered if it could be improv...

Read more »

Guns are cool – Regions

August 10, 2014
By
Guns are cool – Regions

This was supposed to be a post in which General Social Surveys (GSS) data were used to understand a bit more about the causation of differences between states. Thus it was to give additioanl insight than my previous post; Guns are Cool - Differenc...

Read more »

Guns are Cool – Differences between states

August 3, 2014
By
Guns are Cool – Differences between states

Last week my blog showed that there are differences between states in the shootingtracker database. This week it is attempted to understand why states are different. A number of variables were extracted from a few sources, among which gun laws, % ...

Read more »

Guns are Cool – States

July 26, 2014
By
Guns are Cool – States

Last week I looked at time effects of the shootingtracker database. This week I will look at the states. Some (smaller) states never made it on the database. Other states, far too frequently. The worst of these California. After correcting for populati...

Read more »

Guns are cool – time effects

July 19, 2014
By
Guns are cool – time effects

September last year I made a post using the shootingtracker data. It is attempted in shootingtracker to register all shootings with at least four victims, be they wounded or dead. The data starts  January 1st 2013, which means that by now the...

Read more »

odfweave setup and counting logicals

July 12, 2014
By

Two short items in this blogpost. Since it was not obvious how to run odfWeave() in my particular setup, the call I am using. Then there were several people crosstabulating logical vectors, so I wanted to play along, 80 times faster than table().odfWeaveMy particular setup consists of R, 7-zip, libreoffice. Somehow they don't 100% play along when using odfWeave....

Read more »

Stone Flakes V, networks again

July 6, 2014
By
Stone Flakes V, networks again

Last week I tried pcalg. This week deal (Learning Bayesian Networks with Mixed Variables). The aim n this post I want to try something new, a causal graphical model. The aim here is just as much to get myself a feel what these things do as to underst...

Read more »

stone flakes IV

June 29, 2014
By
stone flakes IV

In this post I want to try something new, a causal graphical model. The aim here is just as much to get myself a feel what these things do as to understand how the stone flakes data fit together. DataData are stone flakes data which I analyzed previous...

Read more »

stone flakes III

June 22, 2014
By
stone flakes III

Stone flakes are waste products from the tool making process in the stone age. This is the second post, first post was clustering, second linking to hominid type. The data also contains a more or less continuous age variable, which gives possibili...

Read more »

Stone flakes II

June 16, 2014
By
Stone flakes II

Continuing from last week, the aim is now to classify the stone flakes based on their various properties. Three methods are used. LDA is an obvious standard. A classification tree is both simple and visually appealing. Random forest as a complex method...

Read more »