<div dir="ltr"><div class="gmail_default" style="font-family:verdana,sans-serif;font-size:small">Of course! When u difference 2 fields, they should<br>corr. to the same time... They r not in ur case...<br><br></div><div class="gmail_default" style="font-family:verdana,sans-serif;font-size:small">
-Muthu<br></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Thu, Sep 19, 2013 at 12:45 PM, Phil Klotzbach <span dir="ltr"><<a href="mailto:philk@atmos.colostate.edu" target="_blank">philk@atmos.colostate.edu</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi everyone,<br>
<br>
Thanks so much for your help! In order to zero in on the problem<br>
further, I've tried to simplify the problem by opening two files with<br>
the exact same dimensions (latitude/longitude/time/levels) (<a href="http://uwnd.2009.nc" target="_blank">uwnd.2009.nc</a><br>
and <a href="http://uwnd.2010.nc" target="_blank">uwnd.2010.nc</a>). Basically, what I want to obtain is a height/time<br>
cross-section of the difference between the two years (e.g., zonal wind<br>
in 2010 minus zonal wind in 2009). Let's say in this case, I've opened<br>
up <a href="http://uwnd.2010.nc" target="_blank">uwnd.2010.nc</a> first and then <a href="http://uwnd.2009.nc" target="_blank">uwnd.2009.nc</a> second - using the sdfopen<br>
command. Since I want to create a height/time cross-section, I need to<br>
set the following dimensions before starting the calculation:<br>
<br>
set dfile 1<br>
set t 152 258<br>
set z 1 16<br>
set x 1<br>
set y 1<br>
<br>
Then, I want to create an average over a specific area:<br>
<br>
uave = aave(uwnd, lon=-70, lon=-20, lat=0, lat=30)<br>
<br>
When I display the uave field, it looks perfect - a height/time<br>
cross-section for zonal wind in 2010. But, if I then switch to the<br>
second file (e.g., set dfile 2) (zonal wind in 2009) and try to change<br>
the dimensions on that file, it instantly tells me that uave (the<br>
variable that had the height/time cross-section for 2010) has all<br>
undefined values. For example:<br>
<br>
set dfile 2<br>
set t 152 258<br>
display uave - Gives message saying cannot contour grid - all undefined<br>
values<br>
<br>
I'm not sure how to get around this issue. I tried this with two files<br>
that have the exact same dimensions (e.g., <a href="http://uwnd.2009.nc" target="_blank">uwnd.2009.nc</a> and<br>
<a href="http://uwnd.2010.nc" target="_blank">uwnd.2010.nc</a>) - in order to make sure that it wasn't a time dimension<br>
mismatch that was causing the original problem.<br>
<br>
Is there any way to specify the dimensions in both files at the same<br>
time? Thanks for any additional help.<br>
<br>
Phil<br>
<br>
--<br>
----------------------------------------------------<br>
Phil Klotzbach, Ph.D.<br>
Research Scientist<br>
Department of Atmospheric Science<br>
Colorado State University<br>
Email: <a href="mailto:philk@atmos.colostate.edu">philk@atmos.colostate.edu</a><br>
----------------------------------------------------<br>
<br>
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</blockquote></div><br><br clear="all"><br>-- <br><pre cols="72"><font style="font-family:tahoma,sans-serif">------------------------------------------------------------------<br>Dr.Muthuvel Chelliah, <a href="mailto:eMail%3AMuthuvel.Chelliah@noaa.gov" target="_blank">eMail:Muthuvel.Chelliah@noaa.gov</a><br>
Rm.3008, Climate Prediction Center, Ph:(301) 683-3393<br>NCEP/NWS/NOAA/U.S.Dept.of Commerce,<br>5830, University Research Court, NCWCP<br>College Park, MD 20740.</font><br></pre>
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