<div dir="ltr"><div dir="ltr"><span style="color:rgb(0,0,0);font-family:Helvetica,"Microsoft Yahei",verdana;font-size:14px">Shibo Ma,</span><br><div><br></div><div>The lat and lon coordinate variables in this file are non-standard because the variable names are different than the dimension names. This prevents NCL from correctly attaching the lat and lon coordinates to the data variable. This is a violation of the CF and COARDS standards for Netcdf format.</div><div><br></div><div>You do not need to regrid. It is easy to reattach the coordinate variables in memory, inside your script. Try something like this:</div><div><br></div><div>f = addfile (filename, "r")</div><div>prec = f->precip</div><div>prec&nlat = f->latitude</div><div>prec&nlon = f->longitude</div><div>printVarSummary (prec)</div><div><br></div><div>To ensure proper alignment, also look at the values of lat_bounds and lon_bounds, and compare to latitude and longitude coordinate values. NCL assumes the primary lat and lon coordinates are at the center of each pixel. Some data providers use a different alignment in the primary coordinates, and assume that the user will use lat_bounds and lon_bounds for alignment. If this is the case, then you will need to adjust prec&nlat and prec&nlon in your script.</div><div><br></div><div>--Dave</div><div><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="m_5993154870437774247gmail_attr">On Sun, Jan 27, 2019 at 6:39 AM victor <<a href="mailto:mashibo321@126.com" target="_blank">mashibo321@126.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div style="line-height:1.7;color:rgb(0,0,0);font-size:14px;font-family:Arial"><div>I need some help with GPCP monthly data grid.</div><div>The grid of data seems unusual. When I do ncdump -h, it output like below. I don't know how to deal with something like "latitude(nlat)"?</div><div>Should I need to regriding? What should I do if I want to reshape the data to an usual one?<br></div><div>...</div>variables:<br> float latitude(nlat) ;<br> latitude:long_name = "Latitude" ;<br> latitude:standard_name = "latitude" ;<br> latitude:units = "degrees_north" ;<br> latitude:valid_range = -90.f, 90.f ;<br> latitude:missing_value = -9999.f ;<br> latitude:bounds = "lat_bounds" ;<br> float longitude(nlon) ;<br> longitude:long_name = "Longitude" ;<br> longitude:standard_name = "longitude" ;<br> longitude:units = "degrees_east" ;<br> longitude:valid_range = 0.f, 360.f ;<br> longitude:missing_value = -9999.f ;<br> longitude:bounds = "lon_bounds" ;<br> float time(time) ;<br> time:long_name = "time" ;<br> time:standard_name = "time" ;<br> time:units = "days since 1970-01-01 00:00:00 0:00" ;<br> time:calendar = "julian" ;<br> time:axis = "T" ;<br> float lat_bounds(nlat, nv) ;<br> lat_bounds:units = "degrees_north" ;<br> lat_bounds:comment = "latitude values at the north and south bounds of each pixel." ;<br> float lon_bounds(nlon, nv) ;<br> lon_bounds:units = "degrees_east" ;<br> lon_bounds:comment = "longitude values at the west and east bounds of each pixel." ;<br> float time_bounds(nv, time) ;<br> time_bounds:units = "days since 1970-01-01 00:00:00 0:00" ;<br> time_bounds:comment = "time bounds for each time value" ;<br> float precip(nlat, nlon) ;<br> precip:long_name = "NOAA Climate Data Record (CDR) of Monthly GPCP Satellite-Gauge Combined Precipitation" ;<br> precip:standard_name = "precipitation amount" ;<br> precip:units = "millimeters/day" ;<br> precip:coordinates = "longitude latitude time" ;<br> precip:valid_range = 0.f, 100.f ;<br> precip:cell_methods = "precip: mean" ;<br> precip:missing_value = -9999.f ;<br> float precip_error(nlat, nlon) ;<br> precip_error:long_name = "NOAA CDR of GPCP Satellite-Gauge Combined Precipitation Error" ;<br> precip_error:units = "millimeters/day" ;<br> precip_error:coordinates = "longitude latitude" ;<br> precip_error:valid_range = 0.f, 100.f ;<br><div> precip_error:missing_value = -9999.f ;</div><div>...</div><div style="zoom:1"><div style="font-family:Helvetica,"Microsoft Yahei",verdana">------------------------------------------------------------------------</div><div style="font-family:Helvetica,"Microsoft Yahei",verdana">Shibo Ma(马世波)</div><div style="font-family:Helvetica,"Microsoft Yahei",verdana">Graduate Student</div><div style="font-family:Helvetica,"Microsoft Yahei",verdana">Department of Atmospheric and Oceanic Sciences</div><div style="font-family:Helvetica,"Microsoft Yahei",verdana">School of Physics, Peking University</div><div style="font-family:Helvetica,"Microsoft Yahei",verdana">No. 209 Chengfu Road, Beijing, China</div><div style="font-family:Helvetica,"Microsoft Yahei",verdana">Email: <a href="mailto:mashibo321@126.com" target="_blank">mashibo321@126.com</a></div><div style="font-family:Helvetica,"Microsoft Yahei",verdana">Tel : +86 18810507714</div><div style="font-family:Helvetica,"Microsoft Yahei",verdana">------------------------------------------------------------------------</div></div></div>
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