This looks Interesting
I just ran across info about this new book over at Prometheus;
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A Discussion Paper on Software V&V and SQA
I have a kind of long discussion paper on V&V and SQA that I put together a couple of years ago. I have uploaded a copy V&V and SQA.
Startup Hiccups
I discovered that the spam filter had sucked in all your comments. I’ll be more careful that I clear them ASAP in the future.
Thank you for your excellent comments and I hope you’ll come back often.
Lack of Transparency and some Vital Technical Issues
I have posted several short discussions of software Verification, Validation (V&V) and Software Quality Assurance (SQA) issues a few times at several blogs. I continue to hope that more complete discussions of significant software engineering issues will follow. So far that has not happened. I have made other direct contacts too, but also without success.
Documentation of the models, methods, and software is the key focus relative to V&V and SQA . My research is conducted mainly on the Web. It is entirely possible that I have missed what I’ve been looking for. But no one has yet provided the information that I know is needed in order to provide creditability to projections/predictions from any and all computer software.
All these codes, and all other aspects of all the software used in the climate-change community, belong to us. The continued lack of open documentation is an affront to all of us who have paid for these products and their applications. The climate-change community must open the documentation windows and let some sunshine in.
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Lack of Convergence, Under-Resolution, and Numerical Errors
The Basic Hypotheses
The following is well known but because it is the focus of this discussion I list it for handy reference.
Convergence is Paramount; Nothing else Counts
The fundamental objective of numerical solution of systems of algebraic equations, ordinary differential equations (ODEs) and partial differential equations (PDEs) is to ensure that the approximations made in order to solve the equations do not in fact influence the solutions. In the case of systems of algebraic equations, it must be shown that the stopping criteria applied to iterative solution methods does not influence the accepted solutions. The solutions are independent, to an acceptable level, of the stopping criteria, and the calculated numbers satisfy the equations.
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A GISS ModelE code fragment
The several Global Climate Model or General Circulation Model (GCM) codes around the world are the work horses for the ‘what-if’ studies relative to the Global Average Temperature (and many, many other things) that appear in the IPCC Assessment Reports. There are about 20 of these codes, more or less. The actual models in the codes vary considerably from code-to-code and as a function of time with a given code. The GISS ModelE code is the NASA versions of GCMs.
Some GISS/NASA information about the ModelE GCM code is available here. There you will find information about the documentation of the model and code along with access to download the source and and an online HTML-based code viewer.
This is a test
hey
Models Methods Software 