<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:arial,helvetica,sans-serif;font-size:10pt"><font size="2">So the version of GrADS that I am using is Version 2.0.a8.oga.1. I have been using the ctl file called <span class="Apple-style-span" style="font-family: arial,helvetica,sans-serif; font-size: 14px;">narr-a_221_19790101_0000_000.sub.ctl
to display the grib files in GrADS and it has been working beautifully.
The control file is the following:<br><br><br>dset ^narr-a_221_%y4%m2%d2_%h200_000.sub.grb<br>index ^narr-a_221_19790101_0000_000.sub.grb.idx<br>undef 9.999E+20<br>title narr-a_221_19790101_0000_000.sub.grb<br>* produced by grib2ctl v0.9.12.5p46<br>dtype grib 221<br>options template<br>pdef 349 277 lcc 1 -145.5 1 1 50 50 -107 32463 32463<br>xdef 1111 linear -250 0.333333<br>ydef 247 linear 8 0.333333<br>tdef 90584 linear 00Z01jan1979 3hr<br>* z has 3 levels, for
prs<br>zdef 3 levels<br>925 850 500<br>vars 9<br>HGTprs 3 7,100,0 ** (profile) <span style="border-bottom: 2px dotted rgb(54, 99, 136); cursor: pointer;" class="yshortcuts" id="lw_1281368279_0">Geopotential height</span> [gpm]<br>MSLETmsl 0 130,102,0 ** mean-sea level Mean sea level pressure (ETA model) [Pa]<br>PRMSLmsl 0 2,102,0 ** mean-sea level Pressure reduced to MSL [Pa]<br>TMPprs 3 11,100,0 ** (profile) Temp. [K]<br>TMP10m 0 11,105,10 ** 10 m above ground Temp. [K]<br>UGRDprs 3 33,100,0 ** (profile) u wind [m/s]<br>UGRD10m 0 33,105,10 ** 10 m above ground u wind [m/s]<br>VGRDprs 3 34,100,0 ** (profile) v wind [m/s]<br>VGRD10m 0 34,105,10 ** 10 m above ground v wind [m/s]<br>ENDVARS<br><br>I downloaded the GRIB files from the NCEP <span class="yshortcuts" id="lw_1281368279_1">NARR</span>
dataset, then used grib2ctl to get the ctl file. This is pre-projected
data, the pdef is shown above. After more troubleshooting, this is what
seems to occur. When I use lats4d to make a netCDF file from the grib
files, and I ask for data that is inside of the reference longitude
(-145.5) and standard longitude(-107) as shown in pdef, lats4d just
plain doens't work. I use the command line<br></span></font>lats4d -i narr-a_221_19790101_0000_000.sub -o <a rel="nofollow" target="_blank" href="http://narr2009.nc/"><span class="yshortcuts" id="lw_1281368279_2">narr2009.nc</span></a>
-ftype ctl -lon -145 -110 -lat 25 60 -time 0z1jan2009 21z31dec2009
-mxtimes 2920 -levs 925mb -xvars ugrdprs vgrdprs ugrd10m vgrd10m
msletmsl prmslmsl<br>and it just thinks for a little bit, then shuts grads off. <br>When
I use that same command line but make it outside of the reference and
standard longitudes, lats4d sort of works. For example, if I ask for
data from -160 to -90, and from 25N to 65N, I ends up giving me data
from -160 to -89.667 and from 25N to 65.333N. The data that I am using
is every third degree. So when I compare the grib file to the netCDF
file, the point that is 25N -89.666 in the netCDF file is the same
point as 25.333N -160W in the grib file. So somehow, lats4d is making
an extra array place, and filling it with what is at the begginning of
the array above it. What is going on???<br>Thank you so much for any suggestions you might have!<br>Matt<br><font size="2"><span class="Apple-style-span" style="font-family: arial,helvetica,sans-serif; font-size: 14px;"><br></span></font><div style="font-family: arial,helvetica,sans-serif; font-size: 10pt;"><br><div style="font-family: times new roman,new york,times,serif; font-size: 12pt;"><font size="2" face="Tahoma"><hr size="1"><b><span style="font-weight: bold;">From:</span></b> Arlindo da Silva <dasilva@alum.mit.edu><br><b><span style="font-weight: bold;">To:</span></b> GrADS Users Forum <gradsusr@gradsusr.org><br><b><span style="font-weight: bold;">Sent:</span></b> Wed, August 4, 2010 7:44:53 PM<br><b><span style="font-weight: bold;">Subject:</span></b> Re: [gradsusr] lats4d issues<br></font><br>
On Mon, Aug 2, 2010 at 1:59 PM, Matt Brewer <span dir="ltr"><<a rel="nofollow" ymailto="mailto:mcbrewer83@yahoo.com" target="_blank" href="mailto:mcbrewer83@yahoo.com">mcbrewer83@yahoo.com</a>></span> wrote:<br><div class="gmail_quote"><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div><div style="font-family: arial,helvetica,sans-serif; font-size: 10pt; color: rgb(0, 0, 0);">Folks,<br>I am using lats4d to convert NCEP's NARR data (grib) to netCDF. It only kind of worked. This is what I type into the command line: <br>
<br>lats4d -i narr-a_221_19790101_0000_000.sub -o <a rel="nofollow" target="_blank" href="http://narr2009.nc">narr2009.nc</a> -ftype ctl -lon -160 -90 -lat 25 65 -time 0z1jan2009 21z31dec2009 -mxtimes 2920 -levs 925mb -xvars ugrdprs vgrdprs ugrd10m vgrd10m msletmsl prmslmsl<br>
<br>This works fine except for one issue. It seems to be totally messing up the axis dimensions, causing data to be in incorrect lat/lon locations.Notice how I asked for data from 160W to 90W and 25N to 65N, so with the longitude, that is a span of 70 degrees, and for latitude, it is 40 degrees. So I should get back a geopot. height matrix of 121x211 (there are data points every 1/3rd degree). It seems, in matlab at least, that I get
an array of 122x212. And so what happens is the first point on the second array actually gets saved in the 212th place in the first array, so the second line starts out with what is supose to be the second point in the array. Make sense? When I put the nc file into grads, it has similar issues as well....so something wierd is going on when I run the lats4d script....I just don't know what. So if anyone has any ideas of what is goin on, please help!!!<br>
<br></div></div></blockquote><div><br></div><div>The first step is to make sure GrADS is reading your GRIB file correctly. Go ahead, start GrADS, open your GRIB file, plot it and see if it is doing it correctly:</div><div>
<br></div><div>ga-> open <span class="Apple-style-span" style="font-family: arial,helvetica,sans-serif; font-size: 14px;">narr-a_221_19790101_0000_000.sub</span></div><div><span class="Apple-style-span" style="font-family: arial,helvetica,sans-serif; font-size: 14px;">ga-> d something</span></div>
<div><span class="Apple-style-span" style="font-family: arial,helvetica,sans-serif; font-size: 14px;"><br></span></div><div><span class="Apple-style-span" style="font-family: arial,helvetica,sans-serif; font-size: 14px;">If this is pre-projected data, make sure your PDEF is correct. Once you sort this out, the netcdf version should produce the same results. (Our regression tests do just that: reads a GRIB file, converts to netcdf, then reads the netcdf file back and checks if it gets exactly the same values.)</span></div>
<div><span class="Apple-style-span" style="font-family: arial,helvetica,sans-serif; font-size: 14px;"><br></span></div><div><span class="Apple-style-span" style="font-family: arial,helvetica,sans-serif; font-size: 14px;">One important detail: when asking for help, you need to let us know the particular version of grads, lats4d, and your operating system; basically, the otput of "q config".</span></div>
<div><span class="Apple-style-span" style="font-family: arial,helvetica,sans-serif; font-size: 14px;"><br></span></div><div><span class="Apple-style-span" style="font-family: arial,helvetica,sans-serif; font-size: 14px;"> Arlindo</span></div>
<div><br></div><div><br></div><div> </div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div><div style="font-family: arial,helvetica,sans-serif; font-size: 10pt; color: rgb(0, 0, 0);">
Matt<br></div><br>
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<br></blockquote></div><br><br clear="all"><br>-- <br>Arlindo da Silva<br><a rel="nofollow" ymailto="mailto:dasilva@alum.mit.edu" target="_blank" href="mailto:dasilva@alum.mit.edu">dasilva@alum.mit.edu</a><br>
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