Class: NCVar

Inherits:
NCObject show all
Includes:
NC
Defined in:
lib/io/netcdf.rb

Instance Attribute Summary collapse

Attributes inherited from NCObject

#attributes

Instance Method Summary collapse

Methods included from NC

nc_decode, nc_put_att_simple, nc_put_var_all

Methods inherited from NCObject

#attribute, #get_attributes

Constructor Details

#initialize(ncfile, var_id) ⇒ NCVar

Returns a new instance of NCVar.



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# File 'lib/io/netcdf.rb', line 70

def initialize (ncfile, var_id)
  @ncfile     = ncfile
  @file_id    = ncfile.file_id
  @var_id     = var_id
  @name       = nc_inq_varname(@file_id, var_id)
  @vartype    = nc_inq_vartype(@file_id, var_id)
  @dims       = ncfile.dims.values_at(*nc_inq_vardimid(@file_id, var_id))
  @shape      = @dims.map{|d| d.len}
  @attributes = get_attributes(@file_id, var_id)
  @dims.freeze
  @shape.freeze
end

Instance Attribute Details

#dims ⇒ Object (readonly)

Returns the value of attribute dims.



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# File 'lib/io/netcdf.rb', line 83

def dims
  @dims
end

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/io/netcdf.rb', line 83

def name
  @name
end

Instance Method Details

#[](*argv) ⇒ Object 



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# File 'lib/io/netcdf.rb', line 142

def [] (*argv)
  return get!(*argv)
end

#decode(value) ⇒ Object 



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# File 'lib/io/netcdf.rb', line 105

def decode (value)
  if @attributes.has_key?("_FillValue")
    fill_value = @attributes["_FillValue"]
    case value
    when CArray
      value[:eq, fill_value] = UNDEF
    else
      value = UNDEF if value == fill_value
    end
  end
  if @attributes.has_key?("missing_value")
    missing_values = [@attributes["missing_value"]].flatten
    missing_values.each do |mv|
      case value
      when CArray
        value[:eq, mv] = UNDEF
      else
        if value == mv
          value = UNDEF 
          break
        end
      end
    end
  end
  if @attributes.has_key?("scale_factor")
    value *= @attributes["scale_factor"]
  end
  if @attributes.has_key?("add_offset")
    value += @attributes["add_offset"]
  end
  return value    
end

#definition ⇒ Object 



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# File 'lib/io/netcdf.rb', line 85

def definition
  {
    type: @vartype,
    dim: dims.map{|x| x.name }
  }.update(@attributes)
end

#get(*argv) ⇒ Object 



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# File 'lib/io/netcdf.rb', line 146

def get (*argv)
  if argv.size > 0 and argv[0].is_a?(Struct::CAIndexInfo)
    info = argv.shift
  else
    info = CArray.scan_index(@shape, argv)
  end
  out  = nil
  case info.type
  when CA_REG_ADDRESS
    addr  = info.index[0]
    index = []
    (0..@shape.size-1).reverse_each do |i|
      index[i] = addr % @shape[i]
      addr /= @shape[i]
    end
    out = get_var1(*index)
  when CA_REG_FLATTEN
    out = get_var[nil]
  when CA_REG_POINT
    out = get_var1(*info.index)
  when CA_REG_ALL
    out = get_var()
  when CA_REG_BLOCK
    start = []
    count = []
    stride = []
    info.index.each do |idx|
      case idx
      when Array
        start << idx[0]
        count << idx[1]
        stride << idx[2]
      else
        start << idx
        count << 1
        stride << 1
      end
    end
    if stride.all?{|x| x == 1 }
      out = get_vara(start, count)
    else
      out = get_vars(start, count, stride)
    end
  when CA_REG_SELECT, CA_REG_GRID
    out = get_var[*argv]
  else
    raise "invalid index"
  end
  case out
  when CArray
    return out.compact
  else
    return out
  end
end

#get!(*argv) ⇒ Object 



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# File 'lib/io/netcdf.rb', line 202

def get! (*argv)
  info = CArray.scan_index(@shape, argv)
  case info.type
  when CA_REG_METHOD_CALL
    return decode(get_var)[*argv]
  else
    return decode(get(info, *argv))
  end
end

#get_var ⇒ Object 



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# File 'lib/io/netcdf.rb', line 220

def get_var ()
  return nc_get_var(@file_id, @var_id)
end

#get_var! ⇒ Object 



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# File 'lib/io/netcdf.rb', line 224

def get_var! ()
  return decode(nc_get_var(@file_id, @var_id))
end

#get_var1(*index) ⇒ Object 



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# File 'lib/io/netcdf.rb', line 212

def get_var1 (*index)
  return nc_get_var1(@file_id, @var_id, index)
end

#get_var1!(*index) ⇒ Object 



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# File 'lib/io/netcdf.rb', line 216

def get_var1! (*index)
  return decode(get_var1(*index))
end

#get_vara(start, count) ⇒ Object 



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# File 'lib/io/netcdf.rb', line 228

def get_vara (start, count)
  return nc_get_vara(@file_id, @var_id, start, count)
end

#get_vara!(start, count) ⇒ Object 



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# File 'lib/io/netcdf.rb', line 232

def get_vara! (start, count)
  return decode(nc_get_vara(@file_id, @var_id, start, count))
end

#get_varm(start, count, stride, imap) ⇒ Object 



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# File 'lib/io/netcdf.rb', line 244

def get_varm (start, count, stride, imap)
  return nc_get_varm(@file_id, @var_id, start, count, stride, imap)
end

#get_varm!(start, count, stride, imap) ⇒ Object 



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# File 'lib/io/netcdf.rb', line 248

def get_varm! (start, count, stride, imap)
  return decode(nc_get_varm(@file_id, @var_id, start, count, stride, imap))
end

#get_vars(start, count, stride) ⇒ Object 



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# File 'lib/io/netcdf.rb', line 236

def get_vars (start, count, stride)
  return nc_get_vars(@file_id, @var_id, start, count, stride)
end

#get_vars!(start, count, stride) ⇒ Object 



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# File 'lib/io/netcdf.rb', line 240

def get_vars! (start, count, stride)
  return decode(nc_get_vars(@file_id, @var_id, start, count, stride))
end

#inspect ⇒ Object 



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# File 'lib/io/netcdf.rb', line 92

def inspect
  return "#{@name}#{@dims}"
end

#is_dim? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/io/netcdf.rb', line 96

def is_dim? 
  begin
    nc_inq_dimlen(@file_id, @var_id)
    return true
  rescue RuntimeError
    return false
  end
end

#to_ca ⇒ Object 



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# File 'lib/io/netcdf.rb', line 138

def to_ca
  return self[]
end