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Makes sense. I didn't consider the polarity. Thanks again, Jeff On Wed, Feb 12, 2020 at 9:47 AM Steven Decker <sgdecker@xxxxxxxxxxxxxxxxxx> wrote: > I think the idea for that part of the calculation is to return -1 if urel > is negative and +1 if urel is positive. > > Steve > > On Feb 12, 2020 9:10 AM, Jeffrey Krob - NOAA Federal < > jeffrey.a.krob@xxxxxxxx> wrote: > Thanks for the replies...but that raises a bigger question concerning the > execution of the formula. For example, the 'quo(urel,mag(vecr(urel,0)))' > portion. As I understand it, working from 'inside-out', > vecr(urel,0) will result in V1 = urel & V2 = 0 for each grid point. Then, > the mag(V1,V2) will always be the value of V1 ( SQRT(V1*V1) + (V2*V2) ) > since 0*0=0 & the square root of V1*V1 is...V1. Next, 'quo(urel,V1)' will > always yield 1 since v1 still equals urel. What is the purpose of jumping > through all those hoops if the answer is always "1"...or am I missing > something? > > BTW - this is from some NCEP post processing routine to calculate > slantwise CAPE. This portion calculates 'alpha' where the in-line comment > states: "alpha...with u and v can use alpha to get momentum as needed." > > Thanks again, > Jeff > > On Tue, Feb 11, 2020 at 11:22 AM Steve Decker <sgdecker@xxxxxxxxxxxxxxxxxx> > wrote: > >> Jeff, >> >> That would be my interpretation. It's essentially constructing the zonal >> wind (actually the left-to-right wind on the grid since urel is used) as a >> vector. >> >> Cheers, >> Steve >> >> On 2/11/20 10:57 AM, Jeffrey Krob - NOAA Federal via gembud wrote: >> >> All, >> >> GEMPAK 'newbie' here - came across a script which is passed to the >> DG_GRIDN routine as the following: >> >> custar = >> 'mul(acos(quo(mul(mag(vasv(vecr(urel,0),geo)),quo(urel,mag(vecr(urel,0)))),urel)),RTD)' >> >> Question; concerning the 'vecr(urel,0)' portion, I understand this is a >> call to the DV_VECR (S1, S2) routine to create a vector from 2 scalars. >> However, with the second argument being a '0', is this only returning the >> 'U' portion of the U/V wind vector or is something else going on here? >> >> Thanks in advance, >> Jeff Krob >> NOAA/NESDIS >> >> _______________________________________________ >> NOTE: All exchanges posted to Unidata maintained email lists are >> recorded in the Unidata inquiry tracking system and made publicly >> available through the web. Users who post to any of the lists we >> maintain are reminded to remove any personal information that they >> do not want to be made public. >> >> >> gembud mailing listgembud@xxxxxxxxxxxxxxxx >> For list information or to unsubscribe, visit: >> https://nam02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.unidata.ucar.edu%2Fmailing_lists%2F&data=02%7C01%7Csgdecker%40envsci.rutgers.edu%7C244cffa4bf69475b855908d7af0b287c%7Cb92d2b234d35447093ff69aca6632ffe%7C1%7C0%7C637170334775505732&sdata=K5apE8mmd8Mz9uqNixzHzJYMRO5qyYUO%2F0SHQifmF9Q%3D&reserved=0 >> >> <https://nam02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.unidata.ucar.edu%2Fmailing_lists%2F&data=02%7C01%7Csgdecker%40envsci.rutgers.edu%7C7cb61f2cacdf4ad7edbb08d7afc54893%7Cb92d2b234d35447093ff69aca6632ffe%7C1%7C0%7C637171134178373935&sdata=khe1UkBfKmwuBq6nDIF5PHaItUHeeCa8IW%2FY%2BOf62qQ%3D&reserved=0> >> >> >> -- >> Steve Decker, Associate Teaching Professor >> Director, Meteorology Undergraduate Program >> Department of Environmental Sciences Phone: (848) 932-5750 >> Rutgers University Fax: (732) 932-8644 >> 14 College Farm Rd Email: decker@xxxxxxxxxxxxxxxxxx >> New Brunswick, NJ 08901-8551 >> >>
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