More Sensitivity
I have carried out the sensitivity calculations discussed in this post for the equation discussed in this post and uploaded a file.
Special Pleading Continues
Professor Easterbrook continues the special pleading for exemption that is so common among software developers that have not yet properly addressed important IV&V and SQA issues. This latest version of Professor’s pleading includes the following aspects; (1) a Red Herring, (2) broad generalizations, and (3) appeal to authority.
Appeal to Authority ( His Own )
Professor Easterbrook has not yet cited any of the literature associated with IV&V and SQA for engineering and scientific software. Literature that has presented procedures and processes that have been widely accepted and proven successful. What more can you say about that? Self reference based on a position of authority always fails.
Red Herring
Professor Easterbrook is the only person who has suggested that IV&V and SQA procedures and processes that are applied to commercial software be applied to engineering and scientific software. The subject software is not generally developed fresh from scratch but instead has evolved over decades of time. The engineering community has developed procedures and processes that take into account this obvious and critically important aspect of real-world complex software. Easterbrook attempts to introduce a comparison of apples and zebras into the discussions.
Broad Generalizations
The activities Easterbrook describes are Standard Operating Procedures for every software project that I have experience with. Direct experience. It is not IV&V Lite; it’s plain and simple SOP. SOP is not IV&V and SQA; never has been, will never be.
Collaborative comparisons of software results, and more importantly collaborative comparisons with experimental data, have a very long history in engineering and science software. This software is almost always not commercial software. In my industry, this work started in the mid-1970s. In turbulence modeling the work started in the early 1980s with the (in)famous Stanford Olympics. Infamous because so many calculations got so many different wrong results by so many different ways, sometimes when using the same software; the same models, methods and software. Turbulence is a hard problem.
It is common in many industries for user groups to be formed around a single piece of software. These groups have members that number in the 10s to a few 100s. Importantly the groups focus on a single version of the software, the frozen production-grade version of the code. That’s a lot of eyes looking in detail into all aspects of a single piece of software. From how I understand Easterbrook, the same kind of effort in the GCM community is significantly diluted relative to this standard.
A Prediction
I predict that papers will be written by Professor Easterbrook, reviewed by friendly cohorts who are equally unaware of the literature which has presented the modern methods that are applicable to engineering and science software, published in only the proper peer-reviewed Scientific Journals, and be quoted in the next IPCC reports that the Climate Science GCM software is pure. However, as mentioned above, self reference based solely on a position of authority always fails.
Not Even Wrong
This Comment by John Mashey is simply wrong. Look around this site, and this one, and this one, and this one, and this one, and this one.
Coding Standards Finally Appear
Steve Easterbrook has provided a list of coding standards that are associated with some of the climate models. The first one is for the NASA / GISS ModelE model and code.
Professor Easterbrook states,
Two followup tasks I hope to get to soon – (1) analyze how much these different standards overlap/differ, and (2) measure how much the model codes adhere to the standards.
Here are a few leads relative to Task (2):
The first of these posts was written almost four years ago. The date on the NASA / GISS ModelE document is February 2010. I’m not hopeful that Better late than never will work out in this case. It’s very difficult to retro-fit coding standards to code that is several decades old.
Looks like we’re getting some Traction
This is interesting; Computational science: …Error. From Nature News, even. Comments allowed over there.
Old Science, New Science
Old Science:
Testable hypotheses Validated by Causality. Quality.
See Robert M. Pirsig, 1974.
New Science:
Plausible connections; Validation and Causality optional.
More on ODEs, MMS and Ill-Posed IVPs
First for the nomenclature: ODEs means Ordinary Differential Equations, MMS means the Method of Manufactured Solutions, and IVPs means Initial Value Problems.
This previous post provided some information on these subjects. So far as I know, that post presented the first results for application of MMS to ill-posed IVPs. That post suggested that for the numerical solution methods used therein, the original Lorenz system of 1963 has yet to be correctly solved.
I have some additional results, a summary of which is:
I think the Lorenz system has not yet been accurately integrated by any numerical solution methods. Higher-order methods plus, at the same time, higher precision representation of numbers will give results that might appear to be solutions. But, calculations for sufficiently long time spans will show that errors always increase.
I’ve uploaded a file here.
Physical Realizations of Oxymoron
A Climate Scientist pleads for ( understanding / belief / sympathy / faith / acceptance ) and taking politics out of science by writing an Editorial Opinion column about politics, and while stating:
“Overloading the atmosphere with carbon dioxide from burning fossil fuels is heating the planet, shrinking the Arctic ice cap, melting glaciers and raising sea levels. It is leading to more widespread drought, more frequent heat waves and more powerful hurricanes. [ My bold ]
A two-fer; injecting politics into science and making statements not supported by science.
Americans are Fully Committed to Protecting the Environment
So long as it doesn’t make too much noise.
For me, this situation speaks volumes.
Google Ads
Where are those Google Ads coming from ? Or, more nearly correctly, from where are those Google Ads coming?
Update: Today, this morning, September 3, 2010, I’m not seeing any ???
Do-it-Yourself at RealClimate.Org
This post at realclimate.org is very strange. The phrase do-it-yourself is in the Title for the post and repeated once in the first sentence. Searches show that the phrase does not appear anywhere else in the post.
What a strange way to write about anything. The alleged subject does not appear in the discussion.
Models Methods Software 