Changes between Version 9 and Version 10 of markhDataModelDrafting
 Timestamp:
 01/23/14 00:46:26 (6 years ago)
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markhDataModelDrafting
v9 v10 5 5 * standard_name 6 6 * a controlled vocabulary  the value must be a valid vocabulary item (http://cfpcmdi.llnl.gov/documents/cfstandardnames/) 7 * valid for: 8 * field 9 * dimension coordinate 10 * auxiliary coordinate 11 * cell measure 7 * valid for: ''field'', ''dimension coordinate'', ''auxiliary coordinate'', ''cell measure'' 12 8 * units 13 9 * a controlled vocabulary  the value must be a valid vocabulary item (http://www.unidata.ucar.edu/software/udunits/)names/) 14 * valid for: 15 * field 16 * dimension coordinate 17 * auxiliary coordinate 18 * cell measure 10 * valid for: ''field'', ''dimension coordinate'', ''auxiliary coordinate'', ''cell measure'' 19 11 * comment 20 * valid for: 21 * field 12 * valid for: ''field'' 22 13 * history 23 * valid for: 24 * field 14 * valid for: ''field'' 25 15 * institution 26 * valid for: 27 * field 16 * valid for: ''field'' 28 17 * long_name 29 * valid for: 30 * field 31 * dimension coordinate 32 * auxiliary coordinate 33 * cell measure 18 * valid for: ''field'', ''dimension coordinate'', ''auxiliary coordinate'', ''cell measure'' 34 19 * references 35 * valid for: 36 * field 20 * valid for: ''field'' 37 21 * source 38 * valid for: 39 * field 22 * valid for: ''field'' 40 23 * standard_error_multiplier 41 * valid for: 42 * field 24 * valid for: ''field'' 43 25 * title 44 * valid for: 45 * field 26 * valid for: ''field'' 46 27 * axis 47 28 * In a field, a given value of the axis attribute can occur no more than once among all the dimension and auxiliary coordinates of that field. 48 * valid for: 49 * dimension coordinate 50 * auxiliary coordinate 29 * valid for: ''dimension coordinate'', ''auxiliary coordinate'' 51 30 * calendar 52 * valid for: 53 * dimension coordinate 54 * auxiliary coordinate 31 * valid for: ''dimension coordinate'', ''auxiliary coordinate'' 55 32 * leap_month 56 * valid for: 57 * dimension coordinate 58 * auxiliary coordinate 33 * valid for: ''dimension coordinate'', ''auxiliary coordinate'' 59 34 * leap_year 60 * valid for: 61 * dimension coordinate 62 * auxiliary coordinate 35 * valid for: ''dimension coordinate'', ''auxiliary coordinate'' 63 36 * month_lengths 64 * valid for: 65 * dimension coordinate 66 * auxiliary coordinate 37 * valid for: ''dimension coordinate'', ''auxiliary coordinate'' 67 38 * positive 68 * valid for: 69 * dimension coordinate 70 * auxiliary coordinate 39 * valid for: ''dimension coordinate'', ''auxiliary coordinate'' 71 40 * climatology 72 * valid for: 73 * dimension coordinate 74 * auxiliary coordinate 41 * valid for: ''dimension coordinate'', ''auxiliary coordinate'' 75 42 76 43 77 44 78 The attributes 79 * valid_max 80 * valid_min 81 * valid_range 82 of data variables and coordinate variables are checks on the validity of the values, which could be verified on input and written on output. In this CF data model we assume they do not constrain any manipulations which might be done on the data in memory, and they are not part of the data model. 45 * The attributes 46 * valid_max 47 * valid_min 48 * valid_range 49 * of data variables and coordinate variables are checks on the validity of the values, which could be verified on input and written on output. In this CF data model we assume they do not constrain any manipulations which might be done on the data in memory. 50 * These attribute names are not part of the data model and should not be used except in CFNetCDF. 83 51 84 The attributes 85 * _FillValue 86 * missing_value 87 of data variables specify how missing data is indicated in the data array. This data model supports the idea of missing data, but does not depend on any particular method of indicating it, so these attributes are not part of the model. 88 ''question: is this the case for coords too, auxiliary coords may contain missing data, I believe.'' 52 * The attributes 53 * _FillValue 54 * missing_value 55 * of data variables specify how missing data is indicated in the data array. This data model supports the idea of missing data, but does not depend on any particular method of indicating it. 56 * These attribute names are not part of the data model and should not be used except in CFNetCDF. 57 * ''question: is this the case for coords too, auxiliary coords may contain missing data, I believe?'' 89 58 90 The attributes 91 * add_offset 92 * compress 93 * flag_masks 94 * flag_meanings 95 * flag_values 96 * scale_factor 97 are all used in methods of compressing the data to save space in CFnetCDF files, with or without loss of information. They are not part of this data model because these operations do not logically alter the data, except that the compress attribute implies two alternative interpretations of coordinates (compressed or uncompressed). 59 * The attributes 60 * add_offset 61 * compress 62 * flag_masks 63 * flag_meanings 64 * flag_values 65 * scale_factor 66 * are all used in methods of compressing the data to save space in CFnetCDF files, with or without loss of information. ~~They are not part of this data model because these operations do not logically alter the data, except that the compress attribute implies two alternative interpretations of coordinates (compressed or uncompressed).~~ 67 * These attribute names are not part of the data model and should not be used except in CFNetCDF. 98 68 99 The featureType attribute and associated conventions provide a way of packing multiple fields of the same kind of discrete sampling geometry (timeseries, trajectories, etc.) into a single CFnetCDF data variable, in order to save space, since a multidimensional representation with common coordinate variables is typically very wasteful in such cases. This is a kind of compression. The data model regards each instance of the feature type as an independent field construct. The featureType attribute is a property of each of these field constructs. 69 * The attribute: 70 * featureType 71 * and associated conventions provide a way of packing multiple fields of the same kind of discrete sampling geometry (timeseries, trajectories, etc.) into a single CFnetCDF data variable, in order to save space, since a multidimensional representation with common coordinate variables is typically very wasteful in such cases. This is a kind of compression. The data model regards each instance of the feature type as an independent field construct. The featureType attribute is a property of each of these field constructs. 100 72 101 The attributes:73 ~~The attributes: 102 74 * bounds 103 75 * cell_measures … … 108 80 * formula_terms 109 81 * grid_mapping 110 have various special or structural functions in the CFnetCDF file format. Their functions and the relationships they indicate are reflected in the structure of this data model. These attributes do not correspond to properties in the data model and should not be used ouside the context of CFNetCDF. 82 have various special or structural functions in the CFnetCDF file format. Their functions and the relationships they indicate are reflected in the structure of this data model. These attributes do not correspond to properties in the data model and should not be used ouside the context of CFNetCDF. ~~ 111 83 112 84