Blog Archives

Using IUCN-Data, ArcMap 9.3 and R to Map Species Diversity

October 31, 2011
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Using IUCN-Data, ArcMap 9.3 and R to Map Species Diversity

..I'm overwhelmed by the ever-growing loads of data that's made available via the web. I.e., IUCN collects and hosts spatial species data which is free for download. I'm itching to play with all this data... And, in the end there may arise ...

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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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A Little Webscraping-Exercise…

October 22, 2011
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A Little Webscraping-Exercise…

In R it's quite easy to pull out anything from a webpage and I'll show a little exercise in doing so.Here I retrieve all blog addresses from R-bloggers by the function readLines() and some subsequent data processing.Read more »

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Yet Another One.. Animation with saveHTML / saveVideo from Package ANIMATION

October 12, 2011
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Yet Another One.. Animation with saveHTML / saveVideo from Package ANIMATION

...some more playing with saveHTML, as.raster() and rasterImage(), producing a "flickering screen":Read more »

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Plot Animation with Imported Images

October 10, 2011
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Plot Animation with Imported Images

...I really dig the animation package! ..so here's the outcome of my firsts encounters with saveHTML() - I produced an animation with pre-existing images by utilizing the functions readJPEG() and rasterImage() from the R-packages jpeg and ReadImage...

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Nice Species Distribution Maps with GBIF-Data in R

September 23, 2011
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Nice Species Distribution Maps with GBIF-Data in R

Here's an example of how to easily produce real nice distribution maps from GBIF-data in R with package maps... Read more »

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Use of Classification Trees to Investigate Traits of Invasive Species

September 20, 2011
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Use of Classification Trees to Investigate Traits of Invasive Species

Which traits make an alien species invasive?Due to what traits an alien species becomes established in a foreign flora?This kind of questions could be analysed by the use of recursive partitioning and classification trees..(the below example also inclu...

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Comparing Two Distributions

August 29, 2011
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Comparing Two Distributions

Here I compare two distributions, flowering duration of indigenous and allochtonous plant species. The hypothesis is that alien compared to indigenous plant species exhibit longer flowering periods. Read more »

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Test Difference between Two Proportions & Plot Confidence Intervals

August 11, 2011
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Test Difference between Two Proportions & Plot Confidence Intervals

..an illustrative example for testing proportions and presenting the results.the data: number of indigenous and alien plant species with and without vegetative reproduction. Hypothesis: The proportion of species with vegetative reproduction is differen...

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Two-Way PERMANOVA (with Vegan-Function adonis) Using Customized Contrasts

August 8, 2011
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Two-Way PERMANOVA  (with Vegan-Function adonis) Using Customized Contrasts

...say you have a multivariate dataset and a two-way factorial design - you do a PERMANOVA and the aov-table (adonis is using ANOVA or "sum"-contrasts) tells you there is an interaction - how to proceed when you want to go deeper into the ana...

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