**Data visualization (in R)**, and kindly contributed to R-bloggers)

Following discussion on the comments of the previous post, I thought about how it was possible to draw links going in several directions (i.e. there are no ‘clear’ differences between the levels, and species from level n can interact with species of level n, n+1, n-1, n±k, etc).

This is now done, with a code that is as inelegant as humanly possible. Also, the way to lay the different nodes on the graph (i.e. their ‘trophic level’) should be calculated with a proper method, but (i) I am not a specialist of these metrics, and (ii) it is way too late to do any decent bibliographical research to look them up.

The procedure I use here is quite horrible. I randomly reorder the matrix, and compute the trophic position by elevating each species whenever it eats another species. I repeat this a couple time, and then average the trophic position for each species. The x position is a simple random value, which means that you will probably need to do the launch the code a couple times to get a decent looking network.

The R code can be downloaded here.

**leave a comment**for the author, please follow the link and comment on his blog:

**Data visualization (in R)**.

R-bloggers.com offers

**daily e-mail updates**about R news and tutorials on topics such as: visualization (ggplot2, Boxplots, maps, animation), programming (RStudio, Sweave, LaTeX, SQL, Eclipse, git, hadoop, Web Scraping) statistics (regression, PCA, time series, trading) and more...