Re: write station data into netCDF

Dear Mary, The below is the ncl script and data file. The created netCDF file "pw.nc" still cannot be checked by "cdo". I think the data is the typical station data (lat      lon     data_value). Can you give more suggestion for making the correct netCDF file? Thanks a lot! Mark ----------NCL script------------------- load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl" load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl" begin   fname = "pw.dat"   lines = asciiread(fname,-1,"string")   id = stringtochar(str_get_field(lines(1:),1," "))   id_dims = dimsizes(id)   id_len = id_dims(1)   lat = stringtofloat(str_get_field(lines(1:),2," "))   lon = stringtofloat(str_get_field(lines(1:),3," "))   pwv = stringtofloat(str_get_field(lines(1:),4," "))   delete(lines)   f_out = addfile("pw.nc", "c")   lat!0 = "npts"   lon!0 = "npts"   pwv!0 = "npts"   lat@long_name = "Latitude"   lat@units    = "degrees_north"   lon@long_name = "Longitude"   lon@units    = "degrees_east"   pwv@long_name = "temperature"   pwv@units    = "degC"   f_out->lat = lat   f_out->lon = lon   f_out->pwv = pwv end ----------data file "pw.dat"--------------  ID      LAT      LON      PW BLAC    36.75   -97.25    48.00 BREC    36.41   -97.69    46.30 BURB    36.63   -96.81    49.80 DQUA    34.11   -94.29    45.00 FBYN    40.08   -97.31    38.20 GUTH    35.85   -97.48    46.60 HBRK    38.31   -97.29    34.30 HKLO    35.68   -95.86    50.20 JTNT    33.02  -100.98    39.80 LMNO    36.69   -97.48    47.10 LTHM    39.58   -94.17    40.40 MEDF    36.79   -97.75    46.70 NDS1    37.30   -95.60    39.90 OILT    36.03   -96.50    48.80 PRCO    34.98   -97.52    46.50 REDR    36.36   -97.15    50.40 RWDN    40.09  -100.65    26.40 SA14    36.56  -100.61    22.40 SG01    36.60   -97.49    49.00 SG09    36.43   -98.28    43.20 SG10    36.88   -98.29    41.40 SG11    37.33   -99.31    33.60 SG12    38.20   -99.32    33.90 SG13    38.12   -97.51    36.30 SG14    37.84   -97.02    40.20 SG15    38.20   -95.59    31.70 SG16    37.38   -96.18    42.80 SG18    34.88   -98.20    45.90 SG19    35.36   -98.98    45.30 SG20    35.56   -98.02    47.90 SG22    35.26   -97.48    46.80 VCIO    36.07   -99.22    38.60 ----------cdo message --------------- cdo info: Open failed on >pw.nc< Unsupported file structure ----------ncdump message------------ netcdf pw { dimensions:     npts = 32 ; variables:     float lat(npts) ;         lat:units = "degrees_north" ;         lat:long_name = "Latitude" ;     float lon(npts) ;         lon:units = "degrees_east" ;         lon:long_name = "Longitude" ;     float pwv(npts) ;         pwv:units = "degC" ;         pwv:long_name = "temperature" ; data:  lat = 36.75, 36.41, 36.63, 34.11, 40.08, 35.85, 38.31, 35.68, 33.02, 36.69,     39.58, 36.79, 37.3, 36.03, 34.98, 36.36, 40.09, 36.56, 36.6, 36.43,     36.88, 37.33, 38.2, 38.12, 37.84, 38.2, 37.38, 34.88, 35.36, 35.56,     35.26, 36.07 ;  lon = -97.25, -97.69, -96.81, -94.29, -97.31, -97.48, -97.29, -95.86,     -100.98, -97.48, -94.17, -97.75, -95.6, -96.5, -97.52, -97.15, -100.65,     -100.61, -97.49, -98.28, -98.29, -99.31, -99.32, -97.51, -97.02, -95.59,     -96.18, -98.2, -98.98, -98.02, -97.48, -99.22 ;  pwv = 48, 46.3, 49.8, 45, 38.2, 46.6, 34.3, 50.2, 39.8, 47.1, 40.4, 46.7,     39.9, 48.8, 46.5, 50.4, 26.4, 22.4, 49, 43.2, 41.4, 33.6, 33.9, 36.3,     40.2, 31.7, 42.8, 45.9, 45.3, 47.9, 46.8, 38.6 ; ________________________________ From: Mary Haley <haley@ucar.edu> To: Mark Chan <cym263@yahoo.com> Cc: 李嘉鹏 <lijpbasin@126.com>; NCL Helpline <ncl-talk@ucar.edu> Sent: Tuesday, March 20, 2012 4:50 PM Subject: Re: write station data into netCDF Mark, You are trying to write your variables out as if lat and lon are coordinate arrays of "pwv". If pwv were 2-dimensional, say 64 x 128, and you had a latitude array that was 64 elements, and a longitude array that was 128, *then* you could write out "pwv" with coordinate arrays "lat" and "lon". What you have, however, is 1-dimensional data, each with the same number of points. This is an unstructured grid, and can't be represented by coordinate arrays. You could write out the values with something like:   f_out = addfile("pw.nc", "c")   lat!0 = "npts"   lon!0 = "npts"   pwv!0 = "npts"   lat@long_name = "Latitude"   lat@units    = "degrees_north"   lon@long_name = "Longitude"   lon@units    = "degrees_east"   f_out->lat = lat   f_out->lon = lon   f_out->pwv = pwv Note that you should also add "long_name" and "units" to "pwv" to provide more information about this variable. --Mary

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Received on Wed Mar 21 02:29:19 2012