At 7:34 PM +0100 11/24/06, Giovanni A. Cignoni wrote:
Hi there,
thank for the new versions of the files.
Now we are facing another problem regarding the order of definitions
and uses of variables. The reference manual of DAVE-ML states that
"variableDefs should appear in calculation order" (page 9 of v. 1.9b2).
That "should" is a requirement or just a good practice suggestion?
In the F16 dml there are two cases of variables used before they are
defined (details by G. Mirri are in the following).
I suppose that, at this point in the development of DAVE-ML, the true
requirement is that definitions and uses may appear not in order, but an
ordering must be possible:
- writing them in order is just a good practice for the readability of
the XML;
- if an ordering is not possible (there is a cycle) the DAVE-ML is not
valid.
Is this right?
Thanks in advance,
Giovanni A. Cignoni.
Dr. Cignoni,
I have posted an updated F-16 subsonic aerodynamics example model on
the DAVE-ML website
<http://daveml.nasa.gov/examples.html>
that has the variableDefs sorted correctly.
I will be amplifying the paragraph on variableDefs in the next
version of the reference manual
<http://daveml.nasa.gov/DTDs.html>
to read:
The variableDefs should appear in calculation order; that is, a
variableDef should not appear before the definitions of variables
upon which it is dependent. This is good practice since doing so
avoids a circular reference. If a variable depends upon the output
(dependentVar) of a function it can be assumed that dependence has
been met, since functions are defined later in the DAVEfunc element.
Thanks for the excellent feedback, and I'm sorry to not have caught
this obvious poor example.
-- Bruce Jackson
--
Bruce Jackson <[EMAIL PROTECTED]> Dynamic Systems & Control Branch
8 Langley Boulevard, MS 308 Research & Technology Directorate
NASA Langley Research Center Hampton, Virginia 23681
More info about DAVE-ML: <http://daveml.nasa.gov>
Simulation standards discussion listserv mailto:simstds@larc.nasa.gov
