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>From: "Siffert, Andy" <address@hidden> >Organization: UCAR/Unidata >Keywords: 200202192141.g1JLfjx00339 > > >Hello, >I'm trying to figure out how to plot the difference between two different >PARM at two different times on to one plot. In this case I have created and >.gem file with AVEEU which is the Avg. of the ECMWF from the given times. >AVEMRF is the Avg. of the MRF from the given times. > > >GEMPAK-GDINFO>: >NUM TIME1 TIME2 LEVL1 LEVL2 VCORD PARM >2 020218/1200F156 020218/1200F240 850 PRES AVEEU >13 020219/0000F144 020219/0000F228 850 PRES AVEMRF > >I'm not sure how and what I can use to plot the differences between the two >PARM. > >gdplot will not work because I have two different times. > >that or I'm not specifying my >gddattim and gfunc properly. > >Any idea's would be greatly appreciated. > >Thanks, >Andy > Andy, Use an any gempak program (including gdplot): GVCORD=PRES GLEVEL=850 GDATTIM=020218/1200F156:020218/1200F240 GFUNC=sub(AVEEU,AVEMRF^020219/0000F144:020219/0000F228) You can override time, vertical coordinate and level for any paremeter using the ^, @, and % parameters as specified in the "phelp gparm" help. Also, review the tutorial: http://www.unidata.ucar.edu/packages/gempak/tutorial/diagnostics.html Steve Chiswell