On Wed, Apr 2, 2008 at 10:49 AM, See Hai Ooi <<a href="mailto:axl419@yahoo.com" target="_blank">axl419@yahoo.com</a>> wrote:<br><div class="gmail_quote"><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Dear Mr Arlindo,<br>
<br>
Thank you very much. After modifying slightly<br>
your latest script, it works beautifully. Please see<br>
the attached document.<br>
<br>
Your grads-1.9.0-rc1.win32_superpack.exe has<br>
already included the B.-J.'s functions. I need not<br>
run the script under gradsdods. </blockquote><div><br>You need "gradsdods" to get the latest GFS forecast from NOMAD, not to run the extensions.<br> </div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
I notice that<br>
auxiliary fields replace your original enlarging and<br>
resetting x domain sections. If possible, I would<br>
greatly appreciate it if you could kindly provide me a<br>
brief write-up on the derivation of auxiliary fields<br>
and the advection functions to understand them better.<br>
</blockquote><div><br>I am not sure what you are referring to as "auxiliary fields"; "one" and "cosphi" is what I meant, and these are simply convenience fields. The actual vorticity/divergence is computed by functions madvu/madvv which are fully documented here:<br>
<br> <a href="http://opengrads.org/doc/udxt/libbjt/" target="_blank">http://opengrads.org/doc/udxt/libbjt/</a><br><br>These functions figure out what to do in the boundaries without the need for you to enlarge the domain. Look under "ADVECTION FUNCTIONS". The new version of fish() to be released soon will provide functions fish_psi(u,v) and fish_chi(u,v) which calls these "advection functions" internally. <br>
<br> Arlindo<br></div></div><br>-- <br>Arlindo da Silva<br><a href="mailto:dasilva@alum.mit.edu" target="_blank">dasilva@alum.mit.edu</a>