<div dir="ltr"><div><div><div>NCL has functions to calculate gradients (derivatives).<br><br></div>Your original post did not show that  you wanted gradients of SST. Presumably, these have missing values (land).<br></div> <b>ftcurvd </b>will compute gradients but, as noted in the documentation, it does not allow missing values. <br><br></div>NCL has other functions for gradients:<br><div><br>   <a href="http://www.ncl.ucar.edu/Applications/gradients.shtml">http://www.ncl.ucar.edu/Applications/gradients.shtml</a><br><br></div><div>Some use spherical harmonics which are &quot;highly accurate&quot;  but, again, do not allow for missing values.<br><br>--<br></div><div>The following 6.4.0 function does allow for missing values.<br><br>  <a href="http://www.ncl.ucar.edu/Document/Functions/Contributed/grad_latlon_cfd.shtml">http://www.ncl.ucar.edu/Document/Functions/Contributed/grad_latlon_cfd.shtml</a><br><br></div><div>Read the documentation. This returns a variable of type &#39;list.&#39; The list (container) consists of two variables the zonal and meridional gradients.<br></div><div>---<br></div><div>The following is essentially Example 2:<br><br></div><div>   fsst = addfile(&quot;....&quot;,&quot;r&quot;)<br></div><div>   sst  = f-&gt;SST                        ; assume a rectilinear grid<br></div><div><pre> sst_grad_list = <strong>grad_latlon_cfd</strong> (sst, sst&amp;lat sst&amp;lon, True, False) ; global<br>;sst_grad_list = <strong>grad_latlon_cfd</strong> (sst, sst&amp;lat sst&amp;lon,False, False) ; regional<br></pre><pre>; for clarity, explicitly extract the variables within the list<br></pre>   sst_grad_zonal     = sst_grad_list[0]      ; [...] is NCL syntax for accessing elements of a list<br></div><div>   sst_grad_meriod   = sst_grad_list[1]  <br></div><div>   delete(sst_grad_list)<br></div><div><br></div><div>   printVarSummary(sst_grad_zonal)<br></div><div>   printMinMax(sst_grad_zonal,0)<br></div><div>   print(&quot;---&quot;)<br><div>   printVarSummary(sst_grad_meriod)<br></div><div>   printMinMax(sst_grad_meriod,0)<br></div><br><br></div><div>Good luck<br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Apr 17, 2017 at 4:01 AM, gibies george <span dir="ltr">&lt;<a href="mailto:gibies@tropmet.res.in" target="_blank">gibies@tropmet.res.in</a>&gt;</span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Thanks for your mail.<div><br></div><div>Suppose if I have to calculate zonal gradient of SST(time|:,lat|:,lon|:)</div><div><br></div><div>xcoord=confirm(<a href="https://www.ncl.ucar.edu/Document/Functions/Built-in/dimsizes.shtml" style="font-size:13.3333px;margin:0px;padding:0px;text-decoration-line:none;color:rgb(133,45,133);font-family:verdana,sans-serif;background:rgb(205,232,251)" target="_blank"><strong style="margin:0px;padding:0px">dimsizes</strong></a><span style="color:rgb(0,0,0);font-family:courier;font-size:13.3333px">(SST),<wbr>SST&amp;lon,2)</span></div><div>dsst_dx = <strong style="color:rgb(0,0,0);font-family:courier;font-size:13.3333px;margin:0px;padding:0px">ftcurvd</strong><span style="color:rgb(0,0,0);font-family:courier;font-size:13.3333px">(xcoord,SST,SST&amp;lon)</span></div><div><br></div><div><p style="margin:10px 0px 20px;padding:0px;color:rgb(51,51,51);font-family:verdana,sans-serif;font-size:13.3333px;line-height:12pt">Is this correct ?</p><p style="margin:10px 0px 20px;padding:0px;color:rgb(51,51,51);font-family:verdana,sans-serif;font-size:13.3333px;line-height:12pt"></p><a name="m_-312155885434500526_Errors" style="margin:0px;padding:0px;color:rgb(0,64,255);font-family:verdana,sans-serif;font-size:13.3333px"></a><span style="color:rgb(0,0,0);font-family:verdana,sans-serif;font-size:13.3333px"></span></div></div><div class="gmail_extra"><span class=""><br clear="all"><div><div class="m_-312155885434500526gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div><b style="font-size:12.8px"><font size="2"><br></font></b></div><div><b style="font-size:12.8px"><font size="2"><br></font></b></div><div><b style="font-size:12.8px"><font size="2">Dr. Gibies George,</font></b><br></div><div><b style="font-size:12.8px"><font size="1">Project Scientist C,</font></b><br></div><div><b style="font-size:12.8px"><font size="1">Monsoon Mission,</font></b><br></div><div><b><font size="1">Indian Institute of Tropical Meteorology,<br>Dr. Homi Bhabha Road, </font></b></div><div><b><font size="1">NCL Post Office, </font></b></div><div><b><font size="1">Pashan, Pune 411008, India.<br>Office Teleph  : <a href="tel:+91%2020%202590%204423" value="+912025904423" target="_blank">+912025904423</a><br>Office mail      : <a href="mailto:gibies@tropmet.res.in" target="_blank">gibies@tropmet.res.in</a><br><br>______________________________<wbr>______________<br>Vettikuzhiyil House,<br>Ezhakkaranadu South </font></b><b style="font-size:12.8px"><font size="1">Post Office,</font></b><b><font size="1"><br>Puthencruz-682308, Kochi, India.<br>Mobile number :  <a href="tel:+91%2090285%2023910" value="+919028523910" target="_blank">+919028523910</a>, <a href="tel:+91%2094204%2007392" value="+919420407392" target="_blank">+919420407392</a>, <br>Personal mail : <a href="mailto:gibiesgeorge@gmail.com" target="_blank">gibiesgeorge@gmail.com</a><br><a href="http://sites.google.com/site/gibiesge/" target="_blank">http://sites.google.com/site/<wbr>gibiesge/</a></font></b><div style="margin-left:80px"><div><b><font size="1"><br></font></b></div></div><font color="#274e13"><b><span style="font-family:Arial;font-size:16px">______________________________<wbr>_________________________</span><br>&quot;Please do not print this e-mail unless you really need. Because every 3000 pages cost a tree. </b></font><div><b><font color="#274e13">Save Trees, Save mother Earth.&quot;</font> </b><div style="margin-left:80px"><span style="font-size:small"><font color="#38761d"><b></b></font></span></div><div style="margin-left:80px"><span style="font-size:small"><font color="#38761d"><b></b></font></span></div><font size="1"><br></font></div></div></div></div></div></div></div></div></div></div></div></div></div></div>
<br></span><div><div class="h5"><div class="gmail_quote">On 13 April 2017 at 20:31, Andy <span dir="ltr">&lt;<a href="mailto:awmiller@mit.edu" target="_blank">awmiller@mit.edu</a>&gt;</span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
  
    
  
  <div bgcolor="#FFFFFF" text="#000000">
    <p><font size="+1"><font face="Times New Roman, Times, serif">Yes,
          you can use ftcurvd.</font></font></p>
    <p><font size="+1"><font face="Times New Roman, Times, serif">Andy</font></font><br>
    </p>
    <pre class="m_-312155885434500526m_-4773659930361685905moz-signature" cols="72">Andy Miller
MIT PAOC PhD Candidate

77 Massachusetts Ave | 54-1715
Cambridge, MA 02139

Phone: <a href="tel:(617)%20253-3715" value="+16172533715" target="_blank">617-253-3715</a>
Email: <a class="m_-312155885434500526m_-4773659930361685905moz-txt-link-abbreviated" href="mailto:awmiller@mit.edu" target="_blank">awmiller@mit.edu</a></pre><div><div class="m_-312155885434500526h5">
    <div class="m_-312155885434500526m_-4773659930361685905moz-cite-prefix">On 04/13/2017 02:46 AM, gibies george
      wrote:<br>
    </div>
    </div></div><blockquote type="cite"><div><div class="m_-312155885434500526h5">
      
      <div dir="ltr">Dear friends,
        <div><br>
        </div>
        <div>Is there a function available to find partial derivative of
          a variable along one of its coordinate (say, lonx, laty, levz,
          time, etc ) ?</div>
        <div><br>
        </div>
        <div>thanks and regards<br>
          <div>
            <div class="m_-312155885434500526m_-4773659930361685905gmail_signature" data-smartmail="gmail_signature">
              <div dir="ltr">
                <div dir="ltr">
                  <div dir="ltr">
                    <div dir="ltr">
                      <div dir="ltr">
                        <div dir="ltr">
                          <div dir="ltr">
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                              <div><br>
                              </div>
                              <div><b style="font-size:12.8px"><font size="2"><br>
                                  </font></b></div>
                              <div><b style="font-size:12.8px"><font size="2">Dr. Gibies George,</font></b><br>
                              </div>
                              <div><b style="font-size:12.8px"><font size="1">Project Scientist C,</font></b><br>
                              </div>
                              <div><b style="font-size:12.8px"><font size="1">Monsoon Mission,</font></b><br>
                              </div>
                              <div><b><font size="1">Indian Institute of
                                    Tropical Meteorology,<br>
                                    Dr. Homi Bhabha Road, </font></b></div>
                              <div><b><font size="1">NCL Post Office, </font></b></div>
                              <div><b><font size="1">Pashan, Pune
                                    411008, India.<br>
                                    Office Teleph  : <a href="tel:020%202590%204423" value="+912025904423" target="_blank">+912025904423</a><br>
                                    Office mail      : <a href="mailto:gibies@tropmet.res.in" target="_blank">gibies@tropmet.res.in</a><br>
                                    <br>
______________________________<wbr>______________<br>
                                    Vettikuzhiyil House,<br>
                                    Ezhakkaranadu South </font></b><b style="font-size:12.8px"><font size="1">Post Office,</font></b><b><font size="1"><br>
                                    Puthencruz-682308, Kochi, India.<br>
                                    Mobile number :  <a href="tel:090285%2023910" value="+919028523910" target="_blank">+919028523910</a>,
                                    <a href="tel:094204%2007392" value="+919420407392" target="_blank">+919420407392</a>, <br>
                                    Personal mail : <a href="mailto:gibiesgeorge@gmail.com" target="_blank">gibiesgeorge@gmail.com</a><br>
                                    <a href="http://sites.google.com/site/gibiesge/" target="_blank">http://sites.google.com/site/g<wbr>ibiesge/</a></font></b>
                                <div style="margin-left:80px">
                                  <div><b><font size="1"><br>
                                      </font></b></div>
                                </div>
                                <font color="#274e13"><b><span style="font-family:Arial;font-size:16px">______________________________<wbr>_________________________</span><br>
                                    &quot;Please do not print this e-mail
                                    unless you really need. Because
                                    every 3000 pages cost a tree. </b></font>
                                <div><b><font color="#274e13">Save
                                      Trees, Save mother Earth.&quot;</font>
                                  </b>
                                  <div style="margin-left:80px"><span style="font-size:small"></span></div>
                                  <div style="margin-left:80px"><span style="font-size:small"></span></div>
                                  <font size="1"><br>
                                  </font></div>
                              </div>
                            </div>
                          </div>
                        </div>
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      </div>
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      <fieldset class="m_-312155885434500526m_-4773659930361685905mimeAttachmentHeader"></fieldset>
      <br>
      </div></div><pre>______________________________<wbr>_________________
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