# Posts Tagged ‘ maptools ’

## R-NOLD 2012-05-21 04:46:00

May 21, 2012
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Mapping Philippines earthquake data from January 2011 to January 2012 collected by PHIVOLCS using R ggplot package.I tried to recreate the earthquake map of the Philippines created using maptool and R plot function using ggplot2. Earthquake map ...

## Maps with R, and polygon boundaries

December 21, 2011
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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 ...

## A Simple Example for the Use of Shapefiles in R

October 24, 2011
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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 »

## Clipping a Surface By a Polygon

September 8, 2010
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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 create

## Writing a Spatial Function: The Location Quotient

September 7, 2010
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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) is

## R Maps

September 6, 2010
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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 ways

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

June 10, 2009
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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 in