Thursday, 15 September 2016

The fix

This is a very interesting post by Martyn Plummer on the JAGS News blog, describing how apparently silly details may make a world of difference. I think Martyn says he's now fixed the issue (basically, it appears that JAGS was sensitive to the order in which the model was written, eg at compilation you may have a staggering difference $-$ 16 minute vs 8 seconds $-$ depending on whether you defined the deterministic relationships between parameters first or last).

I'm writing this post mostly as a signpost for myself $-$ I guess you always encounter issues like this, which seem trivial, and the fix is so easy $-$ if only you had a bunch of little workers at your disposal all the time...

LGM 2016

Yesterday I went to beautiful Bath for The Fifth Workshop on Bayesian Inference for Latent Gaussian Models with Applications and give a talk on our work on INLA-SPDE to compute the Expected Value of Partial Perfect Information.  

I couldn't stay for the whole three days, which is a shame because yesterday was really interesting. In the morning, Mike Betancourt (I'm not sure the page I'm linking here is his "official" one, as he's left UCL now) gave an excellent tutorial on Stan. I really enjoyed the morning playing around with the code $-$ in fact, I think we'll try and use it more and more (for example, I will try and integrate this into survHE).

Then in the afternoon, there were two interesting sessions, on talks that had obviously the common thread of LGMs, but were in fact quite diverse. I liked that too!  

Tuesday, 13 September 2016

Careful whisper

PREFACE: This post is only partially a grumpy man's emotional outburst: just hear me out on this one... 

ABSTRACT: A grumpy man vents about spam emails from random scientific (and sometimes pseudo-scientific) journals.


MAIN TEXT: First off, I should say that, luckily, my spam filter works pretty well, so I normally don't really get to see these messages (except for when I take 5 minutes to check what's ended up in the spam $-$ typically these are my 5 minutes of fun...). 

But, I find it super-hilarious to read the weird invitations to contribute papers to the most bizarre journals (that is bizarre with respect to my own field of expertise, of course $-$ they are often good journals, although I think that sometimes the weirdness goes hand in hand with their ridiculousness...). 

Anyway, I particularly really, really like when they start the email with something like this: 
Dear Dr Gianluca@my email address, [of course, to these people my email address is my full name]
We follow very carefully your research and we are impressed by your scientific production. We would be delighted if you could contribute a paper (possibly within the next 20 minutes) to the Journal of Something that has absolutely nothing to do with Statistics, or Health Economics, or anything you've ever done in your life since you were 4 and accidentally sat on your mum's little cactus and all the spiny stems pricked your bottom. [and that, sadly, is a true story...]
Now, that's what I call carefully following somebody's research!

CONCLUSIONS: Incidentally, one of my biggest regrets in life is to have never managed to wear my hair like George Michael. And that's something I've carefully tried to do when I was 14.