<div dir="ltr"><p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">Hi Jennifer and GrADS Users,</span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)"> </span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">I have NetCDF file (<a href="http://nomads.ncep.noaa.gov/pub/data/nccf/com/rtofs/prod/rtofs.20140127/rtofs_glo_2ds_n024_daily_prog.nc">RTOFS
Global</a>) downloaded from </span><span style="font-size:10pt;color:rgb(31,73,125)"><a href="http://nomads.ncep.noaa.gov/pub/data/nccf/com/rtofs/prod/rtofs.20140127/rtofs_glo_2ds_n024_daily_prog.nc">NOMADS
server</a></span><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">. Ncdump of the file is</span></p>
<p class="MsoNormal" style="margin-bottom:12pt"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)"><br>
netcdf D\:/OceanCurrentData/2014/01/22/20140122_rtofs_glo_2ds_n024_daily_prog {<br>
dimensions:<br>
MT = UNLIMITED ; // (1 currently)<br>
Y = 3298 ;<br>
X = 4500 ;<br>
Layer = 1 ;<br>
variables:<br>
double MT(MT) ;<br>
MT:long_name =
"time" ;<br>
MT:units = "days
since 1900-12-31 00:00:00" ;<br>
MT:calendar =
"standard" ;<br>
MT:axis = "T"
;<br>
double Date(MT) ;<br>
Date:long_name =
"date" ;<br>
Date:units = "day
as %Y%m%d.%f" ;<br>
Date:C_format =
"%13.4f" ;<br>
Date:FORTRAN_format =
"(f13.4)" ;<br>
int Layer(Layer) ;<br>
Layer:units =
"layer" ;<br>
Layer:positive =
"down" ;<br>
Layer:axis =
"Z" ;<br>
int Y(Y) ;<br>
Y:point_spacing =
"even" ;<br>
Y:axis = "Y"
;<br>
int X(X) ;<br>
X:point_spacing =
"even" ;<br>
X:axis = "X"
;<br>
float Latitude(Y, X) ;<br>
Latitude:standard_name
= "latitude" ;<br>
Latitude:units =
"degrees_north" ;<br>
float Longitude(Y, X) ;<br>
Longitude:standard_name
= "longitude" ;<br>
Longitude:units =
"degrees_east" ;<br>
Longitude:modulo =
"360 degrees" ;<br>
float u_velocity(MT, Layer, Y, X) ;<br>
u_velocity:coordinates
= "Longitude Latitude Date" ;<br>
u_velocity:standard_name = "eastward_sea_water_velocity" ;<br>
u_velocity:units =
"m/s" ;<br>
u_velocity:_FillValue =
1.267651e+030f ;<br>
u_velocity:valid_range
= -2.09935f, 2.310735f ;<br>
u_velocity:long_name =
" u-veloc. [90.9H]" ;<br>
float v_velocity(MT, Layer, Y, X) ;<br>
v_velocity:coordinates
= "Longitude Latitude Date" ;<br>
v_velocity:standard_name = "northward_sea_water_velocity" ;<br>
v_velocity:units =
"m/s" ;<br>
v_velocity:_FillValue =
1.267651e+030f ;<br>
v_velocity:valid_range
= -2.275719f, 2.274807f ;<br>
v_velocity:long_name =
" v-veloc. [90.9H]" ;<br>
float sst(MT, Y, X) ;<br>
sst:coordinates =
"Longitude Latitude Date" ;<br>
sst:standard_name =
"sea_surface_temperature" ;<br>
sst:units =
"degC" ;<br>
sst:_FillValue =
1.267651e+030f ;<br>
sst:valid_range =
-6.057281f, 32.59346f ;<br>
sst:long_name = "
sea surf. temp. [90.9H]" ;<br>
float sss(MT, Y, X) ;<br>
sss:coordinates =
"Longitude Latitude Date" ;<br>
sss:standard_name =
"sea_surface_salinity" ;<br>
sss:units =
"psu" ;<br>
sss:_FillValue =
1.267651e+030f ;<br>
sss:valid_range =
1.749605f, 40.75261f ;<br>
sss:long_name =
"sea surf. salnity [90.9H]" ;<br>
float layer_density(MT, Layer, Y, X) ;<br>
layer_density:coordinates = "Longitude Latitude Date" ;<br>
layer_density:standard_name = "sea_water_potential_density" ;<br>
layer_density:units =
"sigma" ;<br>
layer_density:_FillValue = 1.267651e+030f ;<br>
layer_density:valid_range = 0.f, 0.f ;<br>
layer_density:long_name
= " density [90.9H]" ;<br>
<br>
// global attributes:<br>
:Conventions =
"CF-1.0" ;<br>
:title = "HYCOM
ATLb2.00" ;<br>
:institution =
"National Centers for Environmental Prediction" ;<br>
:source = "HYCOM
archive file" ;<br>
:experiment =
"90.9" ;<br>
:history =
"archv2ncdf2d" ;<br>
}</span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">The dataset has 32 hybrid layers and a horizontal grid size of
(4500 x 3298) . The grid has an Arctic bi-polar patch north of 47°N and a
Mercator projection south of 47°N through 78.6°S</span><span style="font-family:Arial,sans-serif;color:rgb(31,73,125)">.</span><span class=""><span style="font-size:10pt;font-family:Helvetica,sans-serif;color:black"> <a href="http://polar.ncep.noaa.gov/global/about/?">More details can be found at
link</a>. </span></span><span class=""><span style="font-family:Helvetica,sans-serif;color:black"></span></span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">The CTL file</span><span style="font-family:Arial,sans-serif;color:rgb(31,73,125)"> </span><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">Am using is to display variable values : </span><span style="font-family:Arial,sans-serif;color:rgb(31,73,125)"></span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)"> </span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">dset ^<a href="http://20140122_rtofs_glo_2ds_n024_daily_prog.nc">20140122_rtofs_glo_2ds_n024_daily_prog.nc</a></span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">title HYCOM ATLb2.00 </span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">undef 1.26765e+30 </span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">dtype netcdf </span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">XDEF 4320 LINEAR </span><span style="font-size:10pt;font-family:Arial,sans-serif;color:red;background-color:yellow">74.16 0.08333</span><span style="font-size:10pt;font-family:Arial,sans-serif;color:red"> </span><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)"></span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">YDEF 2160 LINEAR </span><span style="font-size:10pt;font-family:Arial,sans-serif;color:red;background-color:yellow">-90. 0.08333</span><span style="font-size:10pt;font-family:Arial,sans-serif;color:red"> </span><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)"></span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">zdef 1 linear 1 1 </span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">tdef 1 linear 00Z31DEC1900 1mn</span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">options template</span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">PDEF 4500 3298 bilin sequential binary-big </span><span style="font-size:10pt;font-family:Arial,sans-serif;color:red">D:\OceanCurrentData\PDEF\pdef_ncep_global
</span><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)"></span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">vars 8 </span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">Date=>date 0 t date </span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">Latitude=>latitude 0 y,x latitude </span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">Longitude=>longitude 0 y,x longitude </span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">u_velocity=>u_velocity 1 t,z,y,x
u-veloc. [90.9H] </span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">v_velocity=>v_velocity 1 t,z,y,x
v-veloc. [90.9H] </span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">sst=>sst 0 t,y,x sea surf.
temp. [90.9H] </span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">sss=>sss 0 t,y,x sea surf. salnity
[90.9H] </span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">layer_density=>layer_density 1
t,z,y,x density [90.9H] </span></p>
<p class="MsoNormal" style="margin-bottom:12pt"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">endvars</span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">The file used for interpolation </span><span style="font-size:10pt;font-family:Arial,sans-serif;color:red">pdef_ncep_global </span><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">can be
downloaded from <a href="http://nomad3.ncep.noaa.gov/pub/rtofs_global/20140122/">http://nomad3.ncep.noaa.gov/pub/rtofs_global/20140122/</a></span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)"> </span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">When Am displaying current variables u_velocity and v_velocity
in GrADS with following commands<br>
<br>
</span><span style="font-size:10pt;font-family:Arial,sans-serif;color:red">ga->open
C:/OceanCurrentData/2014/01/22/20140122_rtofs_glo_2ds_n024_daily_prog.ctl</span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:red">ga-> set lon -180 180</span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:red">ga-> set lat -90 90<br>
ga-> d skip(u_velocity*1.95,50,50);v_velocity*1.95</span><br>
<br><font color="#1f497d" face="Arial, sans-serif">
The output produced with above commands is attached herewith. The output shown
to grads windows is only for lon 74.16 to 179.95 approx. Understand that
Longitude starts is set 74.16 in XDEF entry in CTL file (as NetCDF file
contains </font><font color="#1f497d" face="Arial, sans-serif">rectilinear</font><font color="#1f497d" face="Arial, sans-serif"> data from 74.16 onward and data is packed 1/12 th the
degree)</font></p><p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)"><br></span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">XDEF 4320 LINEAR </span><span style="font-size:10pt;font-family:Arial,sans-serif;color:red;background-color:yellow">74.16 0.08333</span><span style="font-size:10pt;font-family:Arial,sans-serif;color:red"> </span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:red"> </span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">is defining Start point of LON. </span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)"> </span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)">My Question is : How can I make command </span><span style="font-size:10pt;font-family:Arial,sans-serif;color:red">d
skip(u_velocity*1.95,50,50);v_velocity*1.95 </span><font color="#1f497d" face="Arial, sans-serif">working so that plot is on
entire globe ??? not for just LON 74.16 to 179.65. (Understand that NetCDF file
has linear data from 74.16 to 434, but How can I make these </font><font color="#1f497d" face="Arial, sans-serif">Cartesian</font><font color="#1f497d" face="Arial, sans-serif"> coordinate equivalent to geographical coordinates ????) </font></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)"> </span></p>
<p class="MsoNormal"><font color="#1f497d" face="Arial, sans-serif">Center of Plot is </font><font color="#1f497d" face="Arial, sans-serif">necessarily</font><font color="#1f497d" face="Arial, sans-serif"> to be at POINT (0,0) as plot need
to be overlaid on google map.</font></p>
<p class="MsoNormal" style="margin-bottom:12pt"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)"><br>
<br>
<b>Any help or guidance would be greatly appreciated.</b></span><b></b></p>
<p class="MsoNormal"><b><span style="color:rgb(33,88,104)">Thanks & Regards</span></b></p>
<p class="MsoNormal"><b><span style="color:rgb(33,88,104)">Anil Kumar – </span></b><b><span style="font-family:'Times New Roman',serif;color:rgb(33,88,104)">Sr. </span><span style="color:rgb(33,88,104)">Software Developer</span></b></p>
<p class="MsoNormal"><b><span style="color:rgb(0,161,218)">OceanManager</span><i><span style="color:rgb(33,88,104)"> </span></i><span style="color:rgb(0,161,218)">Inc.</span><span style="color:rgb(0,155,210)"> </span></b><span style="color:black">| </span><a href="http://www.oceanmanager.com/"><span style="color:blue">www.oceanmanager.com</span></a><span style="color:rgb(49,132,155)"></span></p>
<p class="MsoNormal"><span style="color:rgb(220,105,10)">Tel: +1 (801)-758-7101,
(801)-758-7207</span></p>
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