2636 search results for "GIS"

Reading/Writing Stata (.dta) files with Foreign

December 4, 2012
By
Reading/Writing Stata (.dta) files with Foreign

Oftentimes we find ourselves collaborating with others who might not use R or prefer to use Stata to clean and manage their data. Luckily, there is the foreign package that permits handling data of different types (SAS, SPSS, Stata, etc.) within the R...

Read more »

Tutorial: How to make NYT-style bar charts with R

December 3, 2012
By
Tutorial: How to make NYT-style bar charts with R

New York Times columnist Charles Blow needed a chart to accompany his op-ed piece Lincoln, Liberty and Two Americas (about one-party control in state legislatures). So he turned to resident graphic editor Kevin Quealy, who found the source data and used R to create the chart below: If you'd like to create similar charts yourself, Kevin provides a useful...

Read more »

The surprisingly weak case for global warming

December 3, 2012
By
The surprisingly weak case for global warming

I welcome your thoughts on this post, but please read through to the end before commenting. Also, you’ll find the related code (in R) at the end. For those new to this blog, you may be taken aback (though hopefully not bored or shocked!) by how I expose my full process and reasoning. This is

Read more »

Google analytics data extraction in R

December 3, 2012
By
Google analytics data extraction in R

Unlike other posts on this blog this particular post is more focused on coding using R so audience with the developer mindset would like it more than pure business analysts. My goal is to describe an alternate method to use to extract the data from Google Analytics via API into R. I have been using

Read more »

Rolling means (and other functions) with zoo

December 2, 2012
By
Rolling means (and other functions) with zoo

The zoo package is designed for use with (potentially irregular) time series data. It is widely used for any number of applications, but among its most frequently useful functions are the roll* functions, such as rollmean, rollmedian, rollmax, rollapp...

Read more »

Using XML to grab tables from the web

December 1, 2012
By
Using XML to grab tables from the web

We’re going to try, this December, to bring you an “Advent CalendaR,” for each of the 24 days leading up to Christmas. Each day, our hope is to unwrap a useful R package to show you a useful or interesting function inside! Today&#821...

Read more »

Trading with Support Vector Machines (SVM)

November 30, 2012
By
Trading with Support Vector Machines (SVM)

Finally all the stars have aligned and I can confidently devote some time for back-testing of new trading systems, and Support Vector Machines (SVM) are the new “toy” which is going to keep me busy for a while. SVMs are a well-known tool from the area of supervised Machine Learning, and they are used both

Read more »

Lauren Yamane on Matrix Population Models in R

November 30, 2012
By
Lauren Yamane on Matrix Population Models in R

Last week in Davis R Users’ Group, Lauren Yamane showed us how she created and analyzed a stochastic age-structured population in R. Her examples are below. Her original scripts can be found as *.Rmd files here A note to UC Davis students: This topic and others will be covered by Marissa Baskett and Sebastian Schreiber in...

Read more »

Finding a bright object

November 30, 2012
By
Finding a bright object

Finally, to return to the challenge I laid out in the first of this series on image manipulation in R: can we do anything as cool in R as can be done in Mathematica? Like, for example, this illustration of how to search images of the surface of Mars...

Read more »

Shiny is the new Cool

November 29, 2012
By
Shiny is the new Cool

Several of you will probably have tried out the new Shiny package brought to the table by the RStudio guys This is just what I have been looking for and to my mind could provide a quantum leap in the use of R. There have been other packages addressing the need for web user interactivity

Read more »