<div dir="ltr"><div dir="ltr"><div>Rick, that is more good info. It looks like NCL 6.6.2 can read this file directly, by providing one or more explicit dimension sizes as needed. It would be good to examine the array data and metadata (attributes) carefully, before using these data for other work.</div><div><br></div><div>NCO utilities says it can easily convert HDF4 files to Netcdf. Please see section <b>1.6 netCDF2/3/4 and HDF4/5 Support</b> in the current NCO manual. This might be the simplest and safest way -- if it works in this case. Again, verify the results.</div><div><br></div><div><a href="https://nco.sourceforge.net/nco.html" target="_blank">https://nco.sourceforge.net/nco.html</a><br></div><div dir="ltr"><br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Sep 4, 2025 at 4:26 PM Rick Brownrigg <<a href="mailto:brownrig@ucar.edu" target="_blank">brownrig@ucar.edu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div>Thanks for that tip about hdp, Dave. Using NCL to print(f->Feature_Classification_Flags) indicates it has dimensions <br></div><div><br></div><div>Dimensions and sizes: [<span style="color:rgb(255,0,0)">fakeDim18 | 63360</span>] x [fakeDim19 | 5515]</div><div><br></div><div>But hdp shows:</div><div><br></div><div>Variable Name = Feature_Classification_Flags<br> Index = 9<br> Type= 16-bit unsigned integer<br> Ref. = 11<br> Compression method = NONE<br> Rank = 2<br> Number of attributes = 3<br> Dim0: Name=<span style="color:rgb(255,0,0)">fakeDim18<br> Size = UNLIMITED (currently 4224)</span><br> Scale Type = number-type not set<br> Number of attributes = 0<br> Dim1: Name=fakeDim19<br> Size = 5515<br> Scale Type = number-type not set<br> Number of attributes = 0</div><div><br></div><div>So if I have NCL read the variables as:</div><div><br></div><div> foo = f->Feature_Classification_Flags(:4223, :)</div><div><br></div><div>It seems to load fine. If I say</div><div><br></div><div><div> foo = f->Feature_Classification_Flags(:422<span style="color:rgb(255,0,0)">4</span>, :)</div><div><br></div><div>it errs out. The same is true of some of the other variables, ex. Latitude's 1st dimension is only 4224, not 63360.</div><div><br></div><div>Rick</div><div><br></div></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Sep 4, 2025 at 4:06 PM Dave Allured - NOAA Affiliate via ncl-talk <<a href="mailto:ncl-talk@mailman.ucar.edu" target="_blank">ncl-talk@mailman.ucar.edu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div>Where is the documentation for <span style="font-family:"Helvetica Neue",Helvetica,Arial,sans-serif;font-size:13px">CALIPSO files?</span></div><div dir="ltr"><br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Sep 4, 2025 at 4:03 PM Dave Allured - NOAA Affiliate <<a href="mailto:dave.allured@noaa.gov" target="_blank">dave.allured@noaa.gov</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div dir="ltr"><div>HDF4, that is a good clue. The dump utility for HDF4 is "hdp". Do you have it? There are many options. To start, try "hdp -H list" and go from there.</div><div><a href="https://support.hdfgroup.org/hdf4/" target="_blank">https://support.hdfgroup.org/hdf4/</a><br></div><div><br></div><div>Note that HDF4 tools include an HDF4 to HDF5 converter, which they recommend.</div><div><br></div><div>NCL addfile might be identifying this file as HDF-EOS, which is based on HDF4. See addfile documentation. Try switching the filename extension from .hdf to .he4 and see if that improves NCL readability.</div><div><br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Sep 4, 2025 at 3:39 PM Rick Brownrigg <<a href="mailto:brownrig@ucar.edu" target="_blank">brownrig@ucar.edu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div>h5dump can't open it. Running "strings" on that filename indicates its an HDF4.2 file?</div><div><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Sep 4, 2025 at 3:30 PM Dave Allured - NOAA Affiliate via ncl-talk <<a href="mailto:ncl-talk@mailman.ucar.edu" target="_blank">ncl-talk@mailman.ucar.edu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div dir="ltr"><div>More diagnostics needed. Someone please show output from:</div><div><br></div><div>NCL:</div><div><span style="font-family:"Helvetica Neue",Helvetica,Arial,sans-serif;font-size:13px">fh = addfile("CAL_LID_L2_VFM-</span><span style="font-family:"Helvetica Neue",Helvetica,Arial,sans-serif;font-size:13px">Standard-V4-51.2017-08-21T14-</span><span style="font-family:"Helvetica Neue",Helvetica,Arial,sans-serif;font-size:13px">00-11ZD.hdf","r")</span><br></div><div><span style="font-family:"Helvetica Neue",Helvetica,Arial,sans-serif;font-size:13px">print (fh)</span></div><div><span style="font-family:"Helvetica Neue",Helvetica,Arial,sans-serif;font-size:13px"><br></span></div><div><span style="font-family:"Helvetica Neue",Helvetica,Arial,sans-serif;font-size:13px">Linux:</span></div><div><span style="font-family:"Helvetica Neue",Helvetica,Arial,sans-serif;font-size:13px">h5dump -BH </span><span style="font-size:13px;font-family:"Helvetica Neue",Helvetica,Arial,sans-serif">CAL_LID_L2_VFM-</span><span style="font-size:13px;font-family:"Helvetica Neue",Helvetica,Arial,sans-serif">Standard-V4-51.2017-08-21T14-</span><span style="font-size:13px;font-family:"Helvetica Neue",Helvetica,Arial,sans-serif">00-11ZD.hdf</span></div><div dir="ltr"><br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Sep 4, 2025 at 3:23 PM Rick Brownrigg via ncl-talk <<a href="mailto:ncl-talk@mailman.ucar.edu" target="_blank">ncl-talk@mailman.ucar.edu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div>Hi,</div><div><br></div><div>As that file resides on /glade, I was able to access it and duplicate the problem. I can print() that variable, but I can't load it into an NCL variable. Its rather large -- 699MB. Perhaps that's the problem? Interestingly, if I run "ncdump" on that file, I get:</div><div><br></div><div> ncdump /glade/derecho/scratch/zhifengy/data/experiment_input/doe_cloud_africa/CALIPSO/CAL_LID_L2_VFM-Standard-V4-51/test/CAL_LID_L2_VFM-Standard-V4-51.2017-08-21T14-00-11ZD.hdf <br>ncdump: /glade/derecho/scratch/zhifengy/data/experiment_input/doe_cloud_africa/CALIPSO/CAL_LID_L2_VFM-Standard-V4-51/test/CAL_LID_L2_VFM-Standard-V4-51.2017-08-21T14-00-11ZD.hdf: NetCDF: Attempt to use feature that was not turned on when netCDF was built.</div><div><br></div><div>Rick</div><div><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Sep 4, 2025 at 3:16 PM Ehsan Taghizadeh via ncl-talk <<a href="mailto:ncl-talk@mailman.ucar.edu" target="_blank">ncl-talk@mailman.ucar.edu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div><div style="font-size:16px;font-family:"bookman old style","new york",times,serif"><div><div dir="ltr" style="font-family:"bookman old style","new york",times,serif">Hi Zhifeng,</div><div dir="ltr" style="font-family:"bookman old style","new york",times,serif"><br></div><div dir="ltr"><span style="font-family:"bookman old style","new york",times,serif">Could you please add the following commands before your </span><font face="courier new, courier, monaco, monospace, sans-serif">addfile</font> command:</div><div dir="ltr"><div style="font-family:"bookman old style","new york",times,serif"><br></div><div dir="ltr"><font face="courier new, courier, monaco, monospace, sans-serif">exists = isfilepresent("CAL_LID_L2_VFM-Standard-V4-51.2017-08-21T14-00-11ZD.hdf")</font></div><div dir="ltr"><font face="courier new, courier, monaco, monospace, sans-serif">print (exists)</font></div><br></div><div dir="ltr" style="font-family:"bookman old style","new york",times,serif">I wonder if your ncl script and the file are in the same place.</div><div dir="ltr"><span style="font-family:"bookman old style","new york",times,serif">In case it returns </span><font face="courier new, courier, monaco, monospace, sans-serif">True</font>, could you please add the following commands just after reading your file (after <font face="courier new, courier, monaco, monospace, sans-serif">addfile</font> command):</div><div dir="ltr" style="font-family:"bookman old style","new york",times,serif"><br></div><div dir="ltr"><div><div dir="ltr"><font face="courier new, courier, monaco, monospace, sans-serif">names = getfilevarnames( <span style="font-size:16px">"CAL_LID_L2_VFM-Standard-V4-51.2017-08-21T14-00-11ZD.hdf"</span>)</font></div><div><font face="courier new, courier, monaco, monospace, sans-serif">print (names)</font></div></div></div><div dir="ltr" style="font-family:"bookman old style","new york",times,serif"><br></div><div style="font-family:"bookman old style","new york",times,serif"><i style="color:rgb(0,0,0);font-family:"old times",serif"><font size="2">-----------------------------------------------------------------------------</font></i></div><div style="font-family:"bookman old style","new york",times,serif"><div dir="ltr" style="font-family:"old times",serif;font-size:16px"><div dir="ltr" style="color:rgb(0,0,0);font-family:"old times",serif;font-size:16px"> <div><div style="color:rgb(0,0,0);font-family:serif;font-size:16px"><div dir="ltr"><i><font size="2">Best regards,</font></i></div><div dir="ltr"><i><font size="2">Ehsan Taghizadeh</font></i></div></div></div></div></div></div></div><div style="font-family:"bookman old style","new york",times,serif"><br></div>
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On Thursday, September 4, 2025 at 01:37:05 PM PDT, Zhifeng Yang via ncl-talk <<a href="mailto:ncl-talk@mailman.ucar.edu" target="_blank">ncl-talk@mailman.ucar.edu</a>> wrote:</div>
<div><div id="m_-2766392058089310529m_8930272899037599838m_9191078718301350816m_-5504172786685178025m_7961910467383840111m_4902138887088355494m_-8047148026050898503m_2708646701520178821m_2975445544127823336m_1325923296380857432ydpbccc2b23yiv2474529368"><div dir="ltr">Hi all, <div><br></div><div>I am using NCL 6.6.2 to read CALIPSO latitude, longitude, and Feature_Classification_Flags variable from CAL_LID_L2_VFM-Standard-V4-51. </div><div><br></div><div> fh = addfile("CAL_LID_L2_VFM-Standard-V4-51.2017-08-21T14-00-11ZD.hdf","r")</div><div> lath = fh->Latitude(:, 0)<br> lonh = fh->Longitude(:, 0)<br> vfmh = fh->Feature_Classification_Flags</div><div><br></div><div>However, I got the error below</div><div>fatal:HDF: An error occurred while attempting to read variable (Feature_Classification_Flags) from file (/glade/derecho/scratch/zhifengy/data/experiment_input/doe_cloud_africa/CALIPSO/CAL_LID_L2_VFM-Standard-V4-51/test/CAL_LID_L2_VFM-Standard-V4-51.2017-08-21T14-00-11ZD.hdf)</div><div><br></div><div>Do you have any idea about this? Thanks,</div><div><br></div><div>Best,</div><div>Zhifeng</div></div></div></div></div></div></div></div></blockquote></div></blockquote></div></div></div>
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