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<p class="MsoNormal">Dear NCL group,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I am having a similar question as this post <a href="https://www.ncl.ucar.edu/Support/talk_archives/2011/1499.html">
https://www.ncl.ucar.edu/Support/talk_archives/2011/1499.html</a> but unfortunately i didn’t get it..<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I have a 1D data set (station data) as shown below. I would like to filter out the lower orders (order smaller than 2). I do this using “where”, so I get lots of missing values for those stations with lower orders. But these values take
lots of space, so I want to get rid of them and output a much lighter data only for the stations with non-missing values. Below is what my data and my NCL script look like. Could you please take a look and advice? With my script I am still having all the
missing value in my output.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">ncdump -c 200303091200.CHRTOUT_DOMAIN3<o:p></o:p></p>
<p class="MsoNormal">netcdf \200303091200 {<o:p></o:p></p>
<p class="MsoNormal">dimensions:<o:p></o:p></p>
<p class="MsoNormal"> station = 3678397 ;<o:p></o:p></p>
<p class="MsoNormal"> time = 1 ;<o:p></o:p></p>
<p class="MsoNormal">variables:<o:p></o:p></p>
<p class="MsoNormal"> float latitude(station) ;<o:p></o:p></p>
<p class="MsoNormal"> latitude:long_name = "Station latitude" ;<o:p></o:p></p>
<p class="MsoNormal"> latitude:units = "degrees_north" ;<o:p></o:p></p>
<p class="MsoNormal"> float longitude(station) ;<o:p></o:p></p>
<p class="MsoNormal"> longitude:long_name = "Station longitude" ;<o:p></o:p></p>
<p class="MsoNormal"> longitude:units = "degrees_east" ;<o:p></o:p></p>
<p class="MsoNormal"> float streamflow(station) ;<o:p></o:p></p>
<p class="MsoNormal"> streamflow:units = "meter^3 / sec" ;<o:p></o:p></p>
<p class="MsoNormal"> streamflow:long_name = "River Flow" ;<o:p></o:p></p>
<p class="MsoNormal"> int order(station) ;<o:p></o:p></p>
<p class="MsoNormal"> order:long_name = "Strahler Stream Order" ;<o:p></o:p></p>
<p class="MsoNormal">=============<o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">a = addfile("200303101200.CHRTOUT_DOMAIN3"+".nc","r")<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">st = a->streamflow<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">lat = a->latitude<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">lon = a->longitude<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">ord = a->order ;;do filter based on this number, we only want order>2<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">st1 = new(dimsizes(st),typeof(st))<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">lat1 = new(dimsizes(lat),typeof(lat))<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">lon1 = new(dimsizes(lon),typeof(lon))<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">st@_FillValue = -9999<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">st1 = where(ord .gt. 2, st, st@_FillValue)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">lat1 = where(ord .gt. 2, lat, st@_FillValue)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">lon1 = where(ord .gt. 2, lon, st@_FillValue)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">if (.not.all(ismissing(st1))) then ;;I think this “if” statement has some problem, but I am not sure what’s the right one should be..<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif"> system("/bin/rm -f simple.nc")
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif"> ncdf = addfile("simple.nc" ,"c")
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif"> ncdf->streamflow = st1<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif"> ncdf->lat = lat1<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif"> ncdf->lon = lon1<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">;;;;;;or output in txt format<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif"> opt = True<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif"> opt@fout = "foo.txt"<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif"> write_matrix(st1, "10f7.2", opt)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">end if<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">==============<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">Thanks!<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">Jiali Wang, Ph. D<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">Environmental Science Division<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">Argonne National Laboratory<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif">Tel: 630-252-2848<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif"><a href="http://www.evs.anl.gov/about-evs/staff/detail/index.cfm?/Wang/Jiali">http://www.evs.anl.gov/about-evs/staff/detail/index.cfm?/Wang/Jiali</a><o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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