Blog Archives

Great circles lines on a world map with rworldmap and ggplot2 packages

June 22, 2014
By
Great circles lines on a world map with rworldmap and ggplot2 packages

nSometimes you may want to plot maps of the whole world,nthat little bluenspinning sphere thensurface of which provides a home for us all.nCreating maps of smaller areasnis covered in antutorialnI helped create called ‘Introduction to visualising spatial data in R’,nhosted with data and code on angithub repository.nThere are a range of options for plotting the world,...

Read more »

Regular expressions in R vs RStudio

April 14, 2014
By
Regular expressions in R vs RStudio

The 'regex' family of languages and commands is used for manipulating text strings. More specifically, regular expressions are typically used for finding specific patterns of characters and replacing them with others. These technique have a range of applications and R's base installation has powerful regex tools (not to mention add-on packages for string manipulation such as stringr). Yet regex in R is cause of...

Read more »

Regular expressions in R vs RStudio

April 14, 2014
By
Regular expressions in R vs RStudio

The 'regex' family of languages and commands is used for manipulating text strings. More specifically, regular expressions are typically used for finding specific patterns of characters and replacing them with others. These technique have a range of applications and R's base installation has powerful regex tools (not to mention add-on packages for string manipulation such as stringr). Yet regex in R is cause of...

Read more »

Aggregating spatial points by clusters

March 21, 2014
By
Aggregating spatial points by clusters

With ubiquitous collection devices (e.g. smartphones), having too much data may become an increasingly common problem for spatial analysts, even with increasingly powerful computers. This is ironic, because a few short decades ago, too little data was a primary constraint. This tutorial builds on the 'Attribute joins' section of the Creating maps in R tutorial to demonstrate how clusters can be...

Read more »

Aggregating spatial points by clusters

March 21, 2014
By
Aggregating spatial points by clusters

With ubiquitous collection devices (e.g. smartphones), having too much data may become an increasingly common problem for spatial analysts, even with increasingly powerful computers. This is ironic, because a few short decades ago, too little data was a primary constraint. This tutorial builds on the 'Attribute joins' section of the Creating maps in R tutorial to demonstrate how clusters can be...

Read more »

Aggregation of point data to polygons MKII – US states

March 14, 2014
By
Aggregation of point data to polygons MKII – US states

After a colleague of mine requested an illustration of the aggregation technique that was part of an introduction to spatial data in R, I decided to revisit aggregation. The first article I posted here on the subject used data from London; this one is slightly different, using Twitter data aggregated to the state level in the USA. All example code...

Read more »

Aggregation of point data to polygons MKII – US states

March 14, 2014
By
Aggregation of point data to polygons MKII – US states

After a colleague of mine requested an illustration of the aggregation technique that was part of an introduction to spatial data in R, I decided to revisit aggregation. The first article I posted here on the subject used data from London; this one is slightly different, using Twitter data aggregated to the state level in the USA. All example code...

Read more »

R for spatial analysis tutorial + video

January 30, 2014
By

On 24th January 2014 I ran a one day practical course on an "Introduction to Spatial Data Visualisation in R" at the University of Leeds, with the help of demonstrators Rachel Oldroyd and Alistair Leak, who came up from London for the event. The course is designed for people completely new to R, who are especially interested in its spatial...

Read more »

R for spatial analysis tutorial + video

January 30, 2014
By

On 24th January 2014 I ran a one day practical course on an "Introduction to Spatial Data Visualisation in R" at the University of Leeds, with the help of demonstrators Rachel Oldroyd and Alistair Leak, who came up from London for the event. The course is designed for people completely new to R, who are especially interested in its spatial...

Read more »

Spatial clipping and aggregation in R

January 10, 2014
By
Spatial clipping and aggregation in R

A common task in GIS is comparing the spatial extent of one layer with another. Say you have a load of points, some of which overlay a polygon layer. You are only interested in the points that intersect with the points. What do you do? Also, how can you aggregated-up the values contained in the points to correspond with the...

Read more »