Instructions for use of GrADS software to display EMC
Radar and Gauge Precipitation Analyses
Requires Access to:
perl5 (at NCEP available on workstations from /usr/gnu/bin/perl)
c compiler
most recent versions of grads, Grads1.7Beta6
wgrib program and grib2ctl script written by Wesley Ebisuzaki of CPC
(commands in bold type are to be typed by the user)
A. Grads
Obtain the latest version of grads software version 1.7 from:
ftp sprite.llnl.gov
cd /pub/fiorino/grads/beta
get README
get GrADS-1.7Beta6.X.bin.tar.Z
(Where X = your hardware and operating system version)
cd ../dat
get grads.dat.16.tar
cd ../lib
get grads.lib.tar
quit
uncompress and untar the files following the directions in the README file
set up paths in .cshrc file according to directions in README file
B. wgrib.c
Obtain the latest version of wgrib c program from
ftp wesley.wwb.noaa.gov
cd pub/wgrib
get wgrib.c
get porting.txt
quit
compile and test using instructions found in porting.txt
C. grib2ctl.pl
Obtain the latest version of the perl script grib2ctl.pl from
ftp wesley.wwb.noaa.gov
cd pub/wgrib.scripts
get grib2ctl.pl
quit
if necessary, modify path of perl location found at top line of script grib2ctl.pl
Displaying files with GrADS
For example, to view the USAggmmddyyhh.Grb 4 km gauge files
where mm = 2 digit month
dd = 2 digit day
yy = 2 digit year
hh = 2 digit hour
1. Use grib2ctl.pl to create grads .ctl file
determine the time of the first file in the time series you wish to create, and substitute the actual time of the first file USAgg* for the mmddyyhh in the following command
grib2ctl.pl USAggmmddyyhh.Grb > USAgg.ctl
Edit the grads control file:
* replace the actual time mmddyyhh with %m2%d2%y2%h2
* add the word template after yrev in the 6th line
* modify the time parameter from 1 to the number of files in the time series, for example 24 for the entire day from 12 UTC to 12 UTC
* see the example script attached, USAgg.ctl
2. Use gribmap to make the index file for the entire time series of similar files
gribmap -i USAgg.ctl -verif
3. At shell prompt, to verify that the image is okay, type:
gradsnc -l
(After grads Type either -p option for portrait, or -l for landscape)
at the ga> prompt type:
open USAgg.ctl
set gxout shaded
d apcpsfc
(after the image is displayed, type:)
quit
4. Run the example script, USAgg.script to display the gauge image for 1 specific hour.
gradsnc -l
at the ga> prompt type:
exec USAgg.script
(after the image is displayed and you are finished, type:)
quit
To print postscript copy of metafile, type:
gxps -c
USAgg97112714
USAgg97112714.ps
A color postscript file named USAgg97112714.ps is created
6. Attached scripts and tables
Three scripts and one table are required to run grads with the instructions above:
cbarmerc1.gs = color bar script
USAgg.ctl = example control file
USAgg.script = example script to display one gauge analysis