In the earlier post in this series I looked at the ordilabel() function to help tidy up ordination biplots in vegan. An alternative function vegan provides is orditorp(), the last four letters abbreviating the words text or points. That is … Continue reading → [Read more...]

In an earlier post I showed how to customise ordination diagrams produced by our vegan package for R through use of colours and plotting symbols. In a series of short posts I want to cover some of the options available … Continue reading → [Read more...]

Over on the Clastic Detritus blog, Brian Romans posted a nice introduction to plotting in R. At the end of his post, Brian mentioned he would like to colour in areas under the data curve corresponding to particular ranges of … Continue reading → [Read more...]

Weighted averaging regression and calibration is the most widely used method for developing a palaeolimnological transfer function. Such models are used to reconstruct properties of the past lake environment such as pH, total phosphorus, and water temperature with, it has … Continue reading → [Read more...]

Yesterday I rolled up a new version (0.10-0) of analogue, my R package for analysing palaeoecological data. It is now available from CRAN. There were lots of incremental changes to Stratiplot() to improve the quality of the stratigraphic diagrams produced … Continue reading → [Read more...]

I am often found in possession of palaeo core data where the sample identifiers contain a core code or label plus the sample depth. Often these are things generated by colleagues who have used other software where for one reason … Continue reading → [Read more...]

Locally weighted scatterplot smoothing (LOWESS) or local regression (LOESS) is widely used to highlight “signal” in variables from stratigraphic sequences. It is a user-friendly way of fitting a local model that derives its form from the data themselves rather than having … Continue reading → [Read more...]

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Update: As of 18 April 2012 the course is now fully subscribed. Should you wish to be placed on a waiting list please contact Steve Juggins. Analysing Palaeolimnological Data with R 16th — 20th August 2012, University Marine Biological Station … Continue reading → [Read more...]

Hadley Wickham (@hadleywickham) this week mentioned on Twitter his preference for saveRDS() over the more familiar save(). Being a new function to me, I thought I’d take a look… save() and load() will be familiar to many R users. They … Continue reading → [Read more...]

Yesterday I pushed an update of my analogue package to CRAN. The new version is 0.8-0 and contains some new functions, several bug fixes and a major change arising from additions to R 2.14.x requiring all packages to have a … Continue reading → [Read more...]

In previous posts I discussed how to generate a single permutation from a fully-randomised or restricted permutation design using shuffle(). Here I want to briefly mention the shuffleSet() function and illustrate it’s usage. Every time you call shuffle() it has to interpret the … Continue reading → [Read more...]

In a previous post I introduced the permute package and the function shuffle(). In that post I got as far as replicating R’s base function sample(). Here I’ll briefly outline how shuffle() can be used to generate restricted permutations. shuffle() … Continue reading → [Read more...]

Multivariate ordination methods are commonly used in ecology to investigate patterns in species composition in space or time. Constrained ordination methods such as redundancy analysis (RDA) and canonical correspondence analysis (CCA) are effectively just multiple regressions, but we lack the … Continue reading → [Read more...]

Argument passing via ... is a great feature of the R language, allowing you to write wrappers around existing functions that do not need to list all the arguments of the wrapped function. ... is used extensively in S3 methods … Continue reading → [Read more...]

Something I have been doing a lot of work with recently are time series data, to which I have been fitting additive models to describe trends and other features of the data. When modelling temporally dependent data, we often need … Continue reading → [Read more...]

Some months ago, I posted a function that extended the base R function embed() to allow for time delay embedding. Today, David Gonzales alerted me to an inconsistency between embed() and Embed(). The example David used was where Embed() clearly … Continue reading → [Read more...]

NERC recently funded the formation of the UK Lake Ecological Observation Network (UKLEON) as part of the its Networks of Sensors programme. UKLEON is lead by Ian Jones at CEH Lancaster. A fully-funded PhD project is associated with the UKLEON … Continue reading → [Read more...]

Earlier, I looked at the HadCRUT3vgl data set using generalized least squares to investigate whether the trend in temperature since 1995 was statistically significant. Here I want to follow-up one of the points from the earlier posting; namely using a … Continue reading → [Read more...]