# Category emulators

## Visualising input spaces using emulators

In a previous post, I looked at some of the ways we could visualise the input space of climate models, when they are constrained to produce behaviour that looks something like the real world. I used parallel co-ordinates plots and pairs plots to visualise the high (32) dimensional input space of the JULES land surface […]

## Visualising weird input spaces

I’ve been working on a fairly large (~500 member) perturbed-parameter ensemble of the land surface model JULES. The model simulates the global historical land surface, and each ensemble member is forced by the same global reanalysis on the HadGEM2 grid scale. Differences in the model output are therefore caused by the different values of the […]

## Sensitivity analysis with R

After last week’s post, I thought it might be useful to have some practical examples of how to do sensitivity analysis (SA) of complex models (like climate models) with an emulator. SA is one of those things that everyone wants to do at some point, and I’ll be able to point people here for code […]

## Choosing your next design point

You can use the R package DiceOptim to choose the next point to run your expensive simulator. Here’s a gif of function EGO.nsteps() in action, choosing one point at a time, with an initial design of three points. It doesn’t behave in exactly the way I expected, putting lots of points in that well […]

## The great thing about UQ is we know how to spell it

It’s been pretty busy round these parts, here are a few notes from the last month or so. Natural variability – Energy budget Our paper on natural variability in the Earth’s energy budget got a nice write-up from John Abraham in the Guardian. Mat Collins happened to be passing, and took a nice picture of […]

## On the value of observations

I’m pretty happy that our paper on finding the potential value of observations for constraining climate models, was published today in Geoscientific Model Development. I posted about the discussion paper here, and you can download a presentation describing the work here. The paper demonstrates a method for working out how useful a new observation might […]

## Workshop on stats in process modelling

I’ve been at a great workshop on statistical methods for process models (mostly of the Earth system), set up by Lindsay Lee, from Leeds. It was set up as an opportunity for modellers of many stripes to hear about some of the latest statistical techniques being applied to a range of domains, and I think […]