New food web dataset

So, there is a new food web dataset out that was put in Ecological Archives here, and I thought I would play with it. The food web is from Otago Harbour, an intertidal mudflat ecosystem in New Zealand. The web contains 180 nodes, with 1,924 links. Fun stuff… igraph, default layout plot igraph, circle layout plot, nice My funky little gggraph function plotget the gggraph function, and make it better, here at Github

October 14, 2011 · 1 min · Scott Chamberlain

basic ggplot2 network graphs ver2

I posted last week a simple function to plot networks using ggplot2 package. Here is version 2. I still need to work on figuring out efficient vertex placement. Changes in version 2: You have one of three options: use an igraph object, a matrix, or a dataframe (matrices will be converted to data frames within the function) If you have data on food webs similar to that provided in the Takapoto dataset provided in the NetIndices package, you can set trophic = “TRUE”, and gggraph will use the function TrophInd to assign trophic levels (the y axis value) to each vertex/node....

March 23, 2011 · 5 min · Scott Chamberlain

basic ggplot2 network graphs

I have been looking around on the web and have not found anything yet related to using ggplot2 for making graphs/networks. I put together a few functions to make very simple graphs. The bipartite function especially is not ideal, as of course we only want to allow connections between unlike nodes, not all nodes. These functions do not, obviously, take full advantage of the power of ggplot2, but it’s a start....

March 17, 2011 · 2 min · Scott Chamberlain

Bipartite networks and R

Earlier, I posted about generating networks from abundance distributions that you specify. If this post was interesting, check out Jeff Kilpatrick’s website, where he provides code he produced in R and Octave to compare real bipartite networks to ones generated based on ecological variables measured in the field (in our case it was abundance, body size, and nectar production). We used that code for a paper we published. Code was modified from code produced by Diego P....

January 14, 2011 · 1 min · Scott Chamberlain

Ecological networks from abundance distributions

Another grad student and I tried recently to make a contribution to our understanding of the relationship between ecological network structure (e.g., nestedness) and community structure (e.g., evenness)… …Alas, I had no luck making new insights. However, I am providing the code used for this failed attempt in hopes that someone may find it useful. This is very basic code. It was roughly based off of the paper by Bluthgen et al....

January 6, 2011 · 1 min · Scott Chamberlain