Some time ago it was suggested to me something to the effect that most of the people in the Climate Change Community to whom I suggest V&V and SQA issues are critical and require significant attention don’t even know what I’m talking about. Here’s some information that lends support to that observation.
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In a previous post I gave an illustration of how GISS/NASA employees have implemented new and innovative ways to produce inactive code using the capabilities provided by F90/95. I had run across the following statements in routine DIAG.f:
EWATER(J)=EWATER(J)+EL !+W*(SHV*T(I,J,L)*PK(L,I,J)+GRAV
! * *HSCALE*LOG(P(I,J)/PMID(L,I,J)))
The ‘!’ in the first line is going to be very difficult to remember it exists and correctly maintain. Someone might come along and say, “I wonder what that’s doing in the middle of an executable statement.” and promptly un-do the comment. Or un-do the comment of the second line while overlooking the comment in the first line. That would make a screw up on several levels.
Today I have found many more examples of innovative coding by employees of GISS/NASA. It is clear that the NASA Software Quality Assurance procedures are ignored by GISS/NASA. It is equally clear that there are no Software Quality Assurance procedures being applied to the GISS/NASA ModelE code. None.
Update November 2, 2008 down near the end.
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Not my kind of Engineering.
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The persons in charge of the GISS/NASA RealClimate Web site have made it clear that continued discussions of this issue are not welcomed over there. So I’ve moved over here.
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Well, GISS/NASA employee Dr. Gavin Schmidt has done it again. He has given direct proof that the fundamental concepts of software Verification and Validation and other Software Quality Assurance procedures are not in the work universe of GISS/NASA.
Posted in Code Documentation, Code Verification, GISS ModelE Coding, Validation | 7 Comments »
Using the NASA/GISS ModelE code browser I ran across the MODULE CONSTANT in which several constants are setup as parameters.
Posted in Code Documentation, Code Verification, Coding standards, GISS ModelE Coding | 13 Comments »
When the basis of the mathematical models used in AOLGCM models/codes are discussed it is almost always stated that the ‘fundamental laws of conservation and mass and energy’ are at the foundations of the models. This is an incomplete, and somewhat incorrect, statement on several levels.
Conservation of mass and energy is the focus of the following discussion.
Posted in Code Documentation, Validation, Verification | 4 Comments »
The recent results of an Independent Verification of a calculation at Climate Audit and discussed here brings me to mention the editorial policies of scientific journals relative to Verification, Validation, Software Quality Assurance, and Qualfications of models, methods, software, calculations, users, and applications. I have posted comments about the issues relative to publication of peer-reviewed papers on several blogs and given more detailed discussion here.
According to the results of a very unscientific survey by me, the scientific journals have no interest in these very important issues. Many engineering journals, however, have addressed the problems and developed editorial appropriate policies which must be met by authors.
A little over two years ago I wrote letters to the editors of several scientific journals in which the climate change community publishes papers. I have uploaded an example of the letter.
I think it’s time to followup on that letter, for a second time. Read the rest of this entry »
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Here’s an example of what a lack on coding guidelines (or ignoring them) can lead to. From the NASA/GISS ModelE online source code browser:
SUBROUTINE SURFCE 1,30
!@sum SURFCE calculates the surface fluxes which include
!@+ sensible heat, evaporation, thermal radiation, and momentum
!@+ drag. It also calculates instantaneous surface temperature,
!@+ surface specific humidity, and surface wind components.
!@auth Nobody will claim responsibilty
This is the entire header information for a 1228-line routine.
The last line says it all.
Posted in Code Documentation, Code Verification, Coding standards, GISS ModelE Coding | 1 Comment »
“The purpose of computing is insight, not numbers.” Richard Hamming
In order to gain insight, deep understanding of the source of the numbers is of paramount importance. Until deep understanding of the source of the numbers is attained, the numbers do not provide insight. In my opinion, deep understanding of the source of the numbers is best attained by a bottom-up approach. Merely comparing line, contour, or 3-dimensional plots of some calculated numbers does not constitute either understanding or verification/validation.
Read the rest of this entry »
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