Posts Tagged ‘ maptools ’

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

May 21, 2012
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R-NOLD 2012-05-21 04:46:00

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 ...

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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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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 create

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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) is

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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 ways

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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 in

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