Showing posts from February, 2012

Upgrades - hotels, airlines and HPC

I was pointed to this short but interesting blog today: "What's your upgrade?" by @therichbrooks, which makes the point that customers like it when businesses over-deliver on expectations. It is easy to understand what over-deliver might mean for hotels, airlines, rental cars, etc. - upgrades! - but it is equally important for other businesses to consider.

In the contexts of High Performance Computing (HPC) and of software, upgrades are a part of the routine. This covers both upgrades to newer or more powerful hardware (e.g. see the recent upgrades to the Cray supercomputers at HECToR - the UK's national supercomputing service - run by partners including NAG for CSE Support); and software upgrades for new features etc. However, these are all expected and planned upgrades - whilst they do deliver more to the customers, they are not a "over-delivery". And of course, for the service teams, upgrades mean hard work installing, testing, benchmarking and documenti…

Self Improvement - An Algorithm for getting to "empty"

Whether we like it or not, at NAG and many other organizations, we live in an "e-mail" culture meaning that e-mails are how we communicate, receive and retain information. For many of us, e-mails also document both what we have done and what we still have to do. If you are like most in this culture, your e-mail inbox is the hub of your work life. I'm going to suggest an inbox "experiment" for you but first, a little fun.

One of my favorite ways to get to know someone is to ask how they use their inbox. It's almost a litmus test for personalities. So, what does yours say about you? Is yours:

The Black Hole: E-mail gets sucked in but never leaves, a filing cabinet with one gigantic drawer and two folders labelled "In" and "Sent". Periodically, either due to an inspired desire to get organized or "intervention" from a systems administrator, the inbox gets purged and the cycle begins anew.

The Formula One Pit: E-mail comes racing i…

How to solve a NLLS problem using SQP method in Excel?

NLLS stands for nonlinear least-squares and SQP is sequential quadratic programming. So essentially this is an optimization problem, and everyone knows that NAG Library's chapter e04 is the best place to look for optimization solvers. The appropriate NAG routine in our C Library is nag_opt_nlin_lsq (e04unc).
A few weeks ago one of our users contacted NAG and asked for an example program of using e04unc in Excel. NAG and Excel page has quite a few examples and guidelines about using NAG Library in Excel, but we didn't have this particular one.
I wrote this example and now it is available for download on the Excel page. I encourage readers of this blog to download it and play with it on your own. It wasn't difficult to create it, but there was one issue that caused me a nasty headache. Some routines that have callback functions (just as e04unc does) where a vector or matrix is passed to/from a subroutine require usage of Windows API subroutine RtlMoveMemory.

Girls, Geeks, Twitter and Me.

When I get to work one of the first things that I do each morning is check out what’s happening on my Twitter timeline. One Thursday, a couple of weeks ago, one particular tweet caught my eye. It lead me to a great blog 'Girls can love computing; someone just needs to show them how' about the Manchester Girl Geeks. They are a group who are trying to encourage more girls and women to be interested in maths, science and technology. Being a girl myself, (OK, a woman really), and working for a mathematical software company, the article sparked a real interest.

When I was at school, maths wasn’t my best subject, well actually and I’m going to be completely honest with you, it was my worst subject. My fear of all things mathematical started after being made to stand in front of the class reciting times tables. So it’s somewhat ironic that I found myself working at a numerical software company a few years ago, albeit in the marketing department. Had the 'Girl Geeks' been arou…