Author Archives: Doug McNeall

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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 […]

One-at-a-time sensitivity analysis

I use one-at-a-time sensitivity analysis all the time, but it’s not without it’s dangers. It looks like developers are ahead of the statisticians in useful illustrative examples. @ThePracticalDev @testobsessed pic.twitter.com/uKvhzoEPF7 — George Dinwiddie (@gdinwiddie) January 23, 2016 2 unit tests. 0 integration tests pic.twitter.com/V2Z9F4G1sJ — The Practical Dev (@ThePracticalDev) January 14, 2016

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 […]

Gaussian process emulator example

Here’s a little Gaussian process emulator example that I cooked up using the R package DiceKriging. The function is Higdon02, from this useful archive on simulation experiments. I’ve used a constant to initiate the model fit on the smallest data set: km(form=~1, …) rather than a linear term: km(form=~., …) as otherwise you end up […]

Behind the scenes at the new podcast from the Met Office

I’m pretty excited to be part of the regular team for the new Met Office podcast, Mostly Weather. We’re trying to capture a fun, relaxed and hopefully interesting discussion of science, history and little-known facts about weather and climate. I’d like to think that we hit the nerdy-but-accessible sweet spot. We’ve a couple of episodes […]

The best climate science journals (update)

What are the best/most influential/most read/most overrated journals in climate science? This turns out to be quite hard to judge, as climate science these days can seemingly include everything from economics, to biochemistry, and back to psychology. Google Scholar has a list of what it thinks are the best journals in atmospheric science. Here is […]

More ways to win at twitter

Here is a further list of ways to win at Twitter*. Some other ways can be found here. 7. Be heard Demand that your opponent reads everything that you ever wrote, on any subject. If they haven’t, or they won’t, chide them for being ignorant or narrow minded as appropriate. 8. Victim Bully Victim bully. […]