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Hey Cory- Hope you are doing well. So, it's only been a few months, but I finally implemented the SAVG function in the IDV. It's in today's nightly build. > Ok...it's much much later today :-)...dumb question...what is the function > SAVG?, I know of AVG(s1,s2) but never came across savg? I'm not sure what the difference is between SAVG and SAVS. The docs just say that SAVS works on a subset. In the IDV, you would just use SAVG and subset the grid using the map subset in the properties. I only implemented an savg procedure for the formulas. You should now be able to use the Grids->Create a grid diagnostic formula and put in: sub(u,savg(u)) and then choose the U component when prompted for a parameter (or whatever else you want to do). Don Murray ________________________________________ > From: Unidata IDV Support [address@hidden] > Sent: Wednesday, August 12, 2009 6:31 PM > To: Joshua C Demko > Cc: address@hidden; Joshua C Demko > Subject: [IDV #ANI-315803]: calculation of perturbations using SAVS-like > function (GEMPAK) > > Hi Cory- > > > I'm getting slower and slower with these responses...not good...maybe I > > just need a beer. > > No problem. I haven't had time to look at this. We start the IDV training > workshop tomorrow so I've been getting ready for that. > > Anyway...the mean is across 1 time step (mean for one forecast output time > i.e. 1 hour for me). As for the GEMPAK code...I use the function below > > > > GFUNC = sub(un(wnd),savs(un(wnd))) > > What does savs give you over savg. Are you subsetting by region or by level? > > > This function I use in GDCROSS where I set my CXSTNS equal to my lat;long > > of the endpoints. So as I read this, I am subtracting the mean u component > > calculated on each pressure surface along the crossection I defined from > > each u. > > Okay, I understand what you are trying to do now. > > I check this with what I obtain in IDL and both agree. At this stage in my > life, if I get just 2 things to agree I'm stoked (I totally ignore if both > precedures are incorrect in the same way!!). > > > > I have attached a figure which shows several crossectional averages for > > different parameters (only need to focus on the black contour lines with > > show u(prime). I would like to do this in IDV only show a 3D image of u' > > (and other parameters) over the mountain. Essentially a 3D box over the > > mountain to show which levels/sides are contributing more to > > convergence/divergence . > > > > whew.....that's alot...anything else you need on your end? > > That'll do it (except for the savs vs savg question above). > > We'll put this request on the TODO list. We've got a lot of other things on > the list right now (like reading GEMPAK point/sounding files), but we might > be able to sneak it in at some point. The hard part will be to do an average > at each level instead of over the entire volume, but that's just an index > space thing. > > Don > > > ________________________________________ > > From: Unidata IDV Support [address@hidden] > > Sent: Tuesday, July 28, 2009 8:34 AM > > To: Joshua C Demko > > Cc: address@hidden > > Subject: [IDV #ANI-315803]: calculation of perturbations using SAVS-like > > function (GEMPAK) > > > > Hi Cory- > > > > > Full Name: Cory Demko > > > Email Address: address@hidden > > > Organization: UWYO > > > Package Version: 2.7b3 build date:2009-06-16 07:07 UTC > > > Operating System: Windows XP > > > Hardware: Java: home: C:\Program Files\IDV_2.7b3\jre version: 1.6.0_11 > > > j3d:1.5.2 fcs (build4) > > > Description of problem: Don: > > > > > > Sorry for the delay...decided to make a new support email...to answer > > > your question, I am looking at calculating the mean u component along a > > > constant pressure surface to determine u' along the same pressure...I > > > will then make a cross section of u'...for each timestep... > > > > And sorry for our delay. There is no method to do this in the IDV > > currently, but we are thinking about adding this capability. So, I have a > > couple of questions: > > > > - is the mean across all timesteps, or for each timestep? > > - can you send me instructions on how you would do this in GEMPAK? > > > > Don > > > > > > Ticket Details > > =================== > > Ticket ID: ANI-315803 > > Department: Support IDV > > Priority: High > > Status: Open > > > > > Ticket Details > =================== > Ticket ID: ANI-315803 > Department: Support IDV > Priority: High > Status: Open > Ticket Details =================== Ticket ID: ANI-315803 Department: Support IDV Priority: Critical Status: Open