NAGNews 110, November 15 2012

In this issue

NAG Fortran Compiler updated to feature Integer overflow checking

We are thrilled to announce the availability of an update to the NAG Fortran Compiler (Release 5.3.1); this update is now available for both 32 and 64-bit Linux and for Apple Mac OS X. The NAG Fortran Compiler is a full standard implementation of the ISO Fortran 95 language with the addition of almost all Fortran 2003, some Fortran 2008 and the most commonly-used features of OpenMP 3.0.

Release 5.3.1 of the NAG Fortran Compiler is considered to be an incremental update which adds more OpenMP 3.0 functionality and some additional Fortran 2003 and Fortran 2008 features. Furthermore it provides the user with the ability to trap integer overflow at run-time; this feature is provided by virtually no other compiler and is a very useful facility as this type of error is notoriously difficult to identify and locate.

At Release 5.3.1 is fully compatible with the previous release we appreciate that users will want to be able to utilize the updated compiler with the minimum of effort on their part. Consequently an existing Release 5.3 licence key will enable its usage. If you are currently using the NAG Fortran Compiler, Release 5.3, simply download the new version and you can use it immediately.

A comprehensive list of all the new features included in Release 5.3.1 can be found here.

Analysing environmental data variations - Rothamsted, British Geological Survey and NAG Case study

To understand the world around us, scientists measure numerous properties of the environment. Their aim is often to quantify a resource or assess how it changes over space or time. For example, a soil scientist might be interested in how the clay content of soil varies over a landscape, and a hydrologist might want to know how the nitrate concentration in a river varies over time. At its simplest, the variance statistic quantifies this. Scientists are also often interested in the correlation between two variables as this can, in some cases, provide insight into how one variable responds to changes in another.

Typically it is expected that both variance and correlation will change with the scale of the measurements and the locations at which they were made. This is because there are likely to be different processes affecting a given variable at different scales, and these processes might change across space or time. The Discrete Wavelet Transform (DWT) and the Maximum Overlap DWT (MODWT) are signal processing methods that can be used to partition the variance (and correlation) in a series of measure according to given scale intervals and locations (see Percival and Walden, 2000). This type of analysis can aid the understanding of the processes that affect the variable of interest.

Alice Milne from Rothamsted and Murray Lark from the British Geological Survey wrote a program to compute wavelet coefficients and from these estimate wavelet variance and wavelet correlation at several scales. They wanted to compute the confidence intervals for these estimates and used the chi square routine from chapter G01 of the NAG Library for this purpose. The program also looked for significant changes in the wavelet variances and wavelet correlations across the series of data. Changes were deemed significant when they were larger than expected from a stationary series of data with the same auto covariance structure. This analysis uses the NAG Library random number generator, from the suite in G05, and the LU decomposition algorithms, to generate simulated data with a given covariance structures. They also make use of NAG routines to compute correlation and covariance matrices, in the correlation and regression analysis chapter (G02) and routines from the time series analysis chapter (G13). They found the NAG Library functions simple to use, reliable and effective.

Read the full story.

Reminder: Technical Survey 2012 - Let us know your thoughts and enter Kindle Fire Tablet prize draw

The NAG Technical Survey 2012 gives you the opportunity to give us feedback on the software and services we provide and ultimately help shape future direction and functionality. Fundamental to NAG's ethos is collaboration; please help us improve by collaborating with us on this survey. To begin the survey please click here.

To thank you for your time in completing the survey we'll enter you into a prize draw to win one of two Kindle Fire Tablets. We estimate it will take 15 minutes to complete the survey.

Please note that this survey invitation is for users of NAG software and or/services and is intended for completion once only. If you receive an email invitation to complete the survey, and have already completed it, please ignore the email. Winners will be chosen at random and notified by email.

NAG Awards its Lifetime Service Recognition Award to Jeremy Du Croz

On the 21 September 2012, at the NAG AGM, Dr James Davenport presented Mr Jeremy Du Croz the 2012 NAG Life Service Recognition Award. The award was founded to honour the outstanding contributions of past and present employees of NAG; nominations for the award are received annually from NAG's membership.

On presenting Jeremy with his award, James said,

"Thank you to all the members, whether present or past employees, or volunteers, who answered the call for nominations. The outcome this year was to confer this honour on the person who has influenced many others, at NAG and beyond, and it gives me great pleasure to present the NAG Life Service Recognition Award 2012 to Jeremy Du Croz."

Jeremy joined NAG in 1975, and worked on most areas of the NAG Library, exemplifying the standards of rigour and documentation that have been NAG's hallmark, and distinguishes NAG from being "just another software house". The world outside NAG knows him for his work on linear algebra in the form of fundamental contributions to the de facto standard BLAS and LAPACK packages, but over many years he also had a major impact on the NAG Library in the areas of Fast Fourier Transforms, data fitting, random number generation and indeed all over the library.

Jeremy spent some time as manager of NAG's Numerical Libraries Division, in which role he was very much respected. His wisdom and attention to detail is legendary, and inspirational. It is a mark of his influence that, for years after ill-health forced him to retire, people asked, and continue to ask, in all kinds of situations, "What would Jeremy have done?"


Events & Training Courses

12th-15th November 2012. Salt Lake City.
For 24 years, SC has been the principal event for bringing together leading experts in the world of supercomputing. We are proud to have been part of it from the very beginning and are delighted to be present again this year. You can find us at booth number 2431, please come along to say hello, and to discover more about the new developments in our world-famous numerical libraries.

Training Courses Provided by NAG's HECToR Team*

8-10 January 2013
Imperial College London

Parallel Programming with MPI
21-23 January 2013
Imperial College London

An Introduction to CUDA Programming
4-5 March 2013
University of Sheffield

Fortran 95
10-12 December
University of Warwick

These HPC training courses are provided free of charge to HECToR users and UK academics whose work is covered by the remit of one of the participating research councils (EPSRC, NERC and BBSRC). The courses are also open to non-eligible people but will require payment of a course fee. Please see the eligibility page for more details.

Recent blog posts

Keep up to date with NAG's recent blog posts here:

Now the games are over - what's our legacy? How can we inspire a generation?
I really didn't expect to love the Olympics as much as I did. I'm not really into sport and have never taken much interest before, but this time I was absolutely enthralled. London, being the host city, obviously had a bearing on my enthusiasm and enjoyment, but what now the games are over? A lot of talk centred around the Olympics 2012 ethos of 'inspiring a generation' and this got me thinking about NAG's legacy and how we too can inspire.


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