Posts Tagged ‘ maptools ’

Maps with R, and polygon boundaries

December 21, 2011
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Maps with R, and polygon boundaries

With R, it is extremely easy to draw maps. Let us start with something simple, like French regions. Baptiste mentioned on his blog that shapefiles can be downloaded from http://ign.fr/ website. Hence, if you extract the zip file, it is possible to ...

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A Simple Example for the Use of Shapefiles in R

October 24, 2011
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A Simple Example for the Use of Shapefiles in R

A simple example for drawing an occurrence-map (polygons with species' points) with the R-packages maptools and sp using shapefiles.HERE is the example data.Read more »

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Plotting Maps with R

April 26, 2011
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Plotting Maps with R

I stumbled upon this tutorial while not studying and I thought it would be fun to try and plot maps of the San Francisco Bay Area household income, education, population density, poverty, etc...To do this I needed a Shapefile for the Bay Area zip codes...

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Script for Geostatistics with R

March 11, 2011
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Script for Geostatistics with R

I received requests for the script used during the tutorial.All the material is available in the main page of the course.However, in order to facilitate the availability of the scripts to all the viewers of this blog I've put the link to donwnload them...

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R Video Tutorial for Spatial Statistics

March 2, 2011
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R Video Tutorial for Spatial Statistics

Welcome everybody, this is a video tutorial that will try to teach you how to use R for spatial statistics and interpolation. I’m a PhD student in soil science and in particular my project is about digital soil mapping. During my work I often...

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Clipping a Surface By a Polygon

September 8, 2010
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Clipping a Surface By a Polygon

Background: A common function in standard GIS software enables users to create a raster surface and extract values or clip it based on a set of polygons. This may be used in cases where you want analysis to be constrained to within a town’s boundaries or a coastline. This tutorial will outline how to...

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Writing a Spatial Function: The Location Quotient

September 7, 2010
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Writing a Spatial Function: The Location Quotient

Background: In some cases it is necessary to conduct the same analysis multiple times on either the same or different data. In such circumstances it is worth writing a function to simplify the code. In this example the location quotient provides a simple calculation easily written in to a function. The location quotient (LQ)...

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R Maps

September 6, 2010
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R Maps

This is an updated version of my Making Maps with R tutorial. I think the code is lot simpler and it also includes some data for you to play around with. Background: Spatial data are becoming increasingly common, as are the tools available in R to process it. Of course one of the best...

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ggplot2: Plotting Dates, Hours and Minutes

February 24, 2010
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ggplot2: Plotting Dates, Hours and Minutes

Plotting timeseries with dates on x-axis and times on y-axis can be a bit tricky in ggplot2. However, with a little trick this problem can be easily overcome. Let’s assume that I wanted to plot when the sun rises in London in 2010. sunriset function in maptools package calculates the sunrise times using algorithms...

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Creating Tag Cloud Using R and Flash / JavaScript (SWFObject)

June 10, 2009
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Creating Tag Cloud Using R and Flash / JavaScript (SWFObject)

ag cloud is a bunch of words drawn in a graph with their sizes proportional to their frequency; it’s widely used in blogs to visualize tags. We can observe important words quickly from a tag cloud, as they often appear in large fontsize. Tony N. Brown asked how to “graphically represent frequency of words...

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