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Chris, The email you enclosed was in regard to creating a grib back out of a GEMPAK grid. You can do this with the gdgrib program in GEMPAK 5.6 (the code is in $GEMPAK/cource/contrib/hpc). The best way to see how to extract data values otherwise would be to look at gdlist which will access a grid, determine the points within the projected area, and return the data values. Steve Chiswell Unidata User Support >From: address@hidden (Chris Herbster) >Organization: UCAR/Unidata >Keywords: 200104062248.f36MmPL02478 >(I am sending this once again as I discovered that my email client was >having a tough time with an imbedded email header. Since I suspect that >others may also have this problem - thinking that the inserted text was >a new message - I think it's prudent to resend this. Sorry for the >repeat if you have gotten this multiple times.) > > >I had originally sent this message just to Steve, but then realized I should >have sent it to the generic "support" email. > >I've included a message I found in the support archive (between the "--->" >blocks). > >I was wondering if the stubbed code was ever generated - if so I would really >appreciate a copy as this is my first attempt to use the GEMPAK libraries myse > lf >to read a gempak grid file. > >Thanks for any and all help! > >Chris H. > > >______________________________ Forward Header ________________________________ > __ >Subject: stub to read .gem files? >Author: Chris Herbster at BCL >Date: 4/5/01 5:54 PM > > >Steve, > >I found this in the gempak support archive: > > >---> > >>From: Matt Fearon <address@hidden> >>Organization: Desert Research Institute >>Keywords: 199909202052.OAA24442 > >>Steve, >> >>I am performing some calculations in gempak and then >>displaying in grads. >> >>After obtaining the eta grib data via ftp, I am converting the >>grib to gempak grid format. Then I am performing some >>calculations using gempak programs. >> >>After performing calculations and having a single gempak >>grid file, I was wondering if there is a way to re-convert >>the gempak grid file back to grib? Supposedly I can then >>read the grib file into grads. Or a shorter way, if it is possilbe, >>may be to read the gempak grid file straight into grads w/o >>re-converting to grib? >> >>The reason I start in gempak is that I can perform certain >>calculations easier in gempak than in grads, but for the >>final product graphical display, in this case, I prefer grads. >> >>If you have any ideas, please let me know. >>Thank you, >>Matt Fearon >>address@hidden >> >> >> >> > >Matt, >I do not have any way of converting a Gempak file back to grib. >In general, you would need some information for generating the >grib product that is not stored in the Gempak file when it is >decoded. > >You could create a program to convert the Gempak file to the grads >format if you know the requirements there. Reading a gempak >grid file is generally straight forward when using the gemlib.a >library routines- > >IN_BDTA initiallizes the gempak interfaces >GD_OPNF opens the gempak grid file >GD_NGRD determines the number of grids in the file >GD_GGRD returns a grid given its number in the file (eg from 1 to >number of grids) > returns the grid times, levels, vertical coordinate, parameter >name, > number of x,y gridpoints, the nagigation information and the >grid array. > >Once you have the gempak grid read in from the file, you can decide how >to >output the grid into the grads file. > >If you need help creating the stub to read the gempak grid, I can >create that for you. Let me know. > >Steve Chiswell >Unidata User support > > > >GD_GIDN obtains the grid information (level, coordinate, parameter) > >---> > >I'm trying to write some code that will read data from either the RUC or >ETA grids to extract profiles that we're going to use to generate >synthetic satellite images. (Pretty cool stuff.) > >I'm most interested in the last comment you make about creating the stub >to do the read. Did you ever do this for Matt Fearon? I'd *really* >appreciate a head start if you either have the code or could whip it >together .... > >Thanks for any help you can provide. > >Cheers, > >Chris H. > >