ncvarinfo.py

   1 import netCDF4 as nc
   2 import numpy as np
   3 import pandas as pd
   4
   5 def ncvarinfo(ncid,varid):
   6     # ncvarinfo(ncid,varid)
   7     # get info on variable number varid in file f
   8     # returns a structure with fields containing the
   9     # variable propertices and attributes
  10
  11     # Lauren Hearn, September 2018
  12     # transcribed into python from an earlier Matlab code by Jan Mandel and Jon Beezley
  13
  14     v = ncvarinfo()
  15     [v.varname,v.vartype,v.dimids,v.natts]=nc.inqVar(ncid,varid)
  16     v.ndims = length(v.dimids)
  17     # translate variable type
  18     [v.vartype_nc,v.vartype_m] = ncdatatype(v.vartype);
  19     # get dimensions
  20     for idim in v.ndims():
  21         dimid = v.dimids(idim)
  22         [dimname,dimlength] = nc.inqDim(ncid,dimid)
  23         dimname = v.dimname(idim)
  24         if isempty(regexp(dimname,'_subgrid$','ONCE')):
  25             dimlength = v.dimlength(idim)
  26         else:  # fix fire grid variables
  27             #v.dimlength(idim) = 0  # default
  28             stagname = [regexprep(dimname,'_subgrid$',''),'_stag']
  29             try:
  30                 stagid = nc.inqDimID(ncid,stagname)
  31                 [tmp,staglen] = netcdf.inqDim(ncid,stagid)
  32             except Exception as e:
  33                 print 'Warning: dimension ',stagname,' not found' % e
  34                 staglen = 0
  35
  36             atmname = dimname(1,-8)
  37             try:
  38                 atmid = nc.inqDimID(ncid,atmname)
  39                 [tmp,atmlen] = nc.inqDim(ncid,atmid)
  40             except Exception as e:
  41                 print 'Warning: dimension ',atmname,' not found' % e
  42                 atmlen = 0
  43
  44             if atmlen and staglen > 0:
  45                 if atmlen + 1 != staglen:
  46                     print 'Warning: inconsistent',atmname,' and ',stagname
  47
  48             if atmlen == 0 and staglen == 0:
  49                 print 'Warning: dimensions ',stagname,' or ',atmname,' not found, cannot fix fire variable size'
  50                 dimlength = v.dimlength(idim)
  51             else:
  52                 ratio = dimlength / max(staglen,atmlen+1)
  53                 dimlength = dimlength-ratio
  54
  55     # get attributes
  56     v.att_name = pd.DataFrame(0,v.natts)
  57     v.att_datatype = np.zeros(0,v.natts)
  58     v.att_datatype_m = pd.DataFrame(0,v.natts)
  59     v.att_len = np.zeros(0,v.natts)
  60     v.att_value = pd.DataFrame(0,v.natts)
  61     for iatt in v.natts():
  62         attname = nc.inqAttName(ncid,varid,iatt-1)
  63         [datatype,attlen] = nc.inqAtt(ncid,varid,attname)
  64         [att_type_nc,att_type_m] = type(type); # TEXT or DOUBLE
  65         att_value = nc.getAtt(ncid,varid,attname)
  66         attname = v.att_name(iatt)
  67         datatype = v.att_datatype(iatt)
  68         att_type_m = v.att_datatype_m(iatt)
  69         attlen = v.att_len(iatt)
  70         att_value = v.att_value(iatt)