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John Graham-Cumming

http://twitter.com/jgrahamc/

Biography

John Graham-Cumming is a wandering programmer who's lived in the UK, California, New York and France. Along the way he's worked for a succession of technology start-ups, written the award-winning open source POPFile email program and churned out articles for publications such as The Guardian newspaper, Dr Dobbs, and Linux Magazine. His first effort writing a book was the obscure and self-published computer manual GNU Make Unleashed which saturated its target market of 100 readers. Because he has a doctorate in computer security he's deeply suspicious of people who insist on being called Dr., but doesn't mind if you refer to him as a geek. He is the proud owner of a three-letter domain name where he hosts his web site: http://www.jgc.org.

Books

The Geek Atlas The Geek Atlas
by John Graham-Cumming
May 2009
Print: $29.99
Ebook: $23.99

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Blog

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John's blog posts are hosted at:
http://jgc.org/blog/

Well, I was right about one thing

December 18 2009

Just received a nice mail from the Met Office in response to my queries about the data showing that I was right about one thing: there is something odd about the values in Australasia (or as they say, Oceania).I had written to them saying:I've noticed that there seems to be… read more

Adjusting for coverage bias and smoothing the Met Office data

December 18 2009

As I've worked through Uncertainty estimates in regional and global observed temperature changes: a new dataset from 1850 to reproduce the work done by the Met Office I've come up against something I don't understand. I've written to the Met Office about it, but until I get a reply this… read more

Data Visualization Disease

December 17 2009

A few days ago I moaned about an inaccurate and ininterpretable visualization appearing in a book touting its own excellence at visualization. Now, I'm pointed to a visualization of the recently released Met Office land surface temperature record that makes similar mistakes.Folks, data visualization isn't about pretty colours, or slapping… read more

An open source project for my Met Office data analyzer

December 14 2009

Since some other people have been playing with my little Perl program to analyze the Met Office land surface temperature data, I've registered a project at SourceForge so that others can work with me on it.I've also imported my latest version of the script which outputs data about the number… read more

One more thing about the Met Office Land Surface Temperature data

December 14 2009

If you've been following my posts you might have spotted an oddity: if you run the animation of gridding since 1850 it's pretty clear that there weren't many stations going into the mix up until the 1950s.This introduces uncertainty when calculating the hemisphere and global figures. To get an idea… read more

Met Office Land Surface Temperature Data: The Video

December 12 2009

If you don't have all the time to follow all my blog posts on messing with the Met Office data, I've made you a 9 minute YouTube that gives you the highlights... read more

Source code for processing the Met Office Land Surface Temperature data

December 10 2009

The source code used to validate the Met Office data and produce all the visualizations on this blog is here. Enjoy!This code does the following:1. Reads and validates the Met Office Land Surface Temperature data file.2. Spits out errors if it finds problems with the data.3. Produces a Google Maps/Google… read more

There's something seriously odd about "NAPIER NELSON PK"

December 10 2009

If you are messing with the Met Office temperature data there's one file which is really odd: 93/933710. It has temperature data for NAPIER NELSON PK at (-39.5, -176.8) There is actually a Napier Nelson Park in New Zealand but not quite at those coordinates. And I can't find a… read more

Reconstruction of the 1850 to present day warming trend from Met Office data

December 10 2009

Having got the gridding working of the recently released Met Office Land Surface Temperature data it was a short step to reconstruct the temperature trends for 1850 to the present day.I've performed the same gridding as the HadCRUT3 dataset with one exception: I have not removed outliers (the papers on… read more

A first look at gridded data from the Met Office Land Surface Temperature Record

December 08 2009

Well, I've got it working and here's a KML file for you to explore in Google Earth. When I say 'it' I mean:1. Extract the data from the Met Office files2. Check the Normals3. Calculate anomaly data for all stations4. Grid data onto 5 degree square portions of globe using… read more

Problems to watch for in the Met Office Land Surface Temperature Data

December 08 2009

As I've been working through verifying the integrity of this data I've noticed a number of problems/gotchas that you'll need to watch for. These have come up while verifying the 'Normals' data which should be the monthly average data for 1961 to 1990 where there's data and at least 15… read more

Google Earth view of Met Office Land Surface Temperature Data

December 08 2009

The UK Met Office has released a subset of the HadCRUT data that contains temperature observations from 1729 stations around the world. To get started with this data you need to go here.I downloaded the data and wrote a program to verify its integrity (looks ok so far) and then… read more

Facebook's creepy privacy

December 04 2009

Yesterday I received an email from Facebook that I assumed was some sort of scam. In fact, it was totally genuine and I received it because someone I know is using Facebook to promote their business.Here's the email: I know three of those people, but the three people in the… read more

Whoops. There's a third bug in that code.

December 03 2009

So, I'm sitting on the bus this morning executing CRU's IDL code in my head when I suddenly realized that there's another more subtle bug in the exact same code I was looking at the other day.Here's the critical loop once more: for i=0.0,nel do begin x=cos(a)*(xkm/110.0)*(1.0/cos(!pi*pts1(i,0)/180.0))+pts1(i,1) x=x(-179.9) y=sin(a)*(xkm/110.0)+pts1(i,0) y=y>(-89.9)… read more

We should probably feel sorry for Ian 'Harry' Harris at CRU

December 01 2009

Reading through the code and then through his HARRY_READ_ME.TXT you can see a man up against something that was slightly outside his ability. I don't mean that in a nasty way; what was needed was a professional programmer and not a professional scientist.In the midst of the file we find… read more

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Multimedia

Webcast: Around the world in 32 minutes with The Geek Atlas
June 24, 2009
Duration: Approximately 60 minutes. Cost: Free In this webcast, author John Graham-Cumming presents a tour of 32 places from his book, The Geek Atlas, in 32 minutes. From Jaipur to Hawaii, via Spain, Paris, London, New York and beyond, The Geek Atlas...

John Graham-Cumming