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Hi Ana, You can express the addition with multiple ADD calls: ADD(ADD(P06M^00,P06M^06),ADD(P06M^12,P06M^18)) -Michael > Thanks for help. > > I use the GFUNC=ADD() but this function only accept two values. How i > add more values, for example. ADD(P06M^00;P06M^06;P06M^12;P06M^18) > Sum the P06m for all hours. > > Thanks :) > > Ana > > > Unidata GEMPAK Support escreveu: > > Ana, > > > > If you have both grids in the same file, you can compute the average using > > GDDIAG, where "GEM_FILE" is the name of the file containing both grids: > > > > GDFILE = GEM_FILE > > GDOUTF = GEM_FILE > > GFUNC = avg(P06M^f06,P06M^f18) > > GDATTIM = 100409/1200 > > GLEVEL = 0 > > GVCORD = none > > GRDNAM = PAVG^f012 > > GRDTYP = S > > GPACK = > > GRDHDR = > > PROJ = > > GRDAREA = > > KXKY = > > MAXGRD = 200 > > CPYFIL = GEM_FILE > > ANLYSS = > > > > In this example we're using P06M forecasts for f06 and f18 from > > 100409/1200, you'll want to adjust these to suit your file/grids date and > > time. also the GRDNAM = PAVG can be anything you prefer. See > > > > http://www.unidata.ucar.edu/cgi-bin/gempak/manual/programs_index?gddiag > > > > and > > > > http://www.unidata.ucar.edu/cgi-bin/gempak/manual/variables_index?grdnam > > > > for more help. > > > > Michael James > > Unidata > > > > > > > >> Hello Tom, How are you? > >> > >> I don't know if you can help me..but... > >> > >> I'm trying to do the interpolation the P06M for 2 hours the synop data > >> for plot with gdcntr. > >> > >> I'm using the oagrid for create and oabsfc for input surface file. But i > >> don't know How i plus P06M for hours (06 and 18) and generate > >> interpolation. > >> > >> With gempak is possible plus the values for two hours and after create > >> the grid file?? > >> > >> Thanks > >> Ana > >> > >> > >> p.s.: sorry if my English is not very good. > >> > >> I will send for you the gif with one hour P06M that i create. > >> > >> > >> > > > > > > Ticket Details > > =================== > > Ticket ID: DHU-135597 > > Department: Support GEMPAK > > Priority: Normal > > Status: Open > > > > > > Ticket Details =================== Ticket ID: DHU-135597 Department: Support GEMPAK Priority: Normal Status: Open