'$RCSfile: eml-attribute.xsd,v $' Copyright: 2000 Regents of the University of California and the National Center for Ecological Analysis and Synthesis For Details: http://knb.ecoinformatics.org/ '$Author: cjones $' '$Date: 2001-12-14 20:26:07 $' '$Revision: 1.20 $' This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA eml-attribute The EML Attribute Module describes all attributes (variables) in a data entity (e.g., data table). The description includes the name and definition of each attribute, its type, its allowable range (if numeric), definitions of coded values, and other pertinent information. Attribute descriptors Container of attribute descriptors of all attributes in a dataset. Eml-attribute element represents a list of all attributes in a dataset. The eml-attribute was introduced into EML 1.4 as eml-variable. Unique identifier The unique identifier of this metadata file or object. The identifier field provides a unique identifier for this metadata documentation. It will most likely be part of a sequence of numbers or letters that are meaningful in a larger context, such as a metadata catalog. That larger system can be identified in the "system" attribute. Multiple identifiers can be listed corresponding to different catalog systems. nceas.3.2 ]]> The 'identifier' field is derived from the eml-dataset meta_file_id filed in EML 1.4. Catalog system The catalog system in which this identifier is used. This element gives the name of the catalog system in which this identifier is used. It is useful to determine the scope of the identifier, and to determine the semantics of the various subparts of the identifier. Unresolved issue: can or should this be a URI/URL pointing to the catalog system, or just the name? nceas.3.2]]> New to EML 2.0. Attribute descriptor Descriptor of an attribute in the dataset. Attribute element is a descriptor of an attribute in the data file identified by its name. The attribute element can contain information about the attribute's definition, format, storage type and data range, or missing value. The attribute element was introduced into EML 1.4 as variable. Attribute name Attribute name for identification This element specifies name of the attribute (field) in the dataset. This information is typically used as a column header for the field/variable in a spreadsheet. It is usually terse, without spaces, and can be used to "name" a column in a table definition statement. spden The attributeName was introduced into EML 1.4. Attribute label A label that better describes an attribute than its name A brief label used to describe the attribute. This is often needed because attribute names are usually very terse- often shortened to 8 characters or less to deal with analysis systems. A label is provided as a concise but more descriptive representation of the attribute. "Species Density" is a label for attribute with name "spden" Introduced in EML 2.0 Attribute definition Precise definition of attribute in the dataset This element gives a precise definition of attribute in the dataset. It explains the contents of the attribute fully and possibly provides pointers to the methods used to generate the attribute data. "spden" is the number of individuals of all macroinvertebrate species found in the plot The attributeDefinition was introduced into EML 1.4. Unit of measurement Unit of measurement for data in the field This element specifies unit of measurement for data in the field. Integer count of individuals within plot The unit was introduced into EML 1.4. Data type Description of data type for this field This element describes the data type for data in the field like: integer, floating point, character, string. integer, floating point, character, string From storageType, introduced in EML 1.4. Code definition Description of any codes associated with the attribute This element describes any code associated with the attribute. The format will typically be : "code" has "definition", e.g. "1" = "high", "2" = "medium", "3" = "low" The codeDefinition was introduced into EML 1.4. Code Code associated with the attribute This element specifies a code associated with the attribute. "1" would be the code for "high" (where high is the description of the code) The code element was introduced into EML 1.4. Code definition Description of the code associated with the attribute. This element describes the code associated with the attribute. "high" would be the definition for a code of "1" The definition element is from EML 1.4. Source of code The name of the source for this code and its definition The name of the source from which this code and its associated definition are drawn. This is commonly used for identifying standard coding systems, like the FIPS standard for postal abbreviations for states in the US. In other cases, the coding may be the researcher's customized way of recording and classifying their data, and no external "source" would exist. ISO country codes Introduced in EML 2.0 Text domain Description of a free-text domain pattern for the attribute This element describes a free text domain for the attribute. By default, if pattern is missing or empty, then any text is allowed. If pattern is present, then it is interpreted as a regular expression constraining the allowable character sequences for the attribute. Typically, a textdomain will have an empty pattern or one that constrains allowable values. For example, '[0-9]{3}-[0-9]{3}-[0-9]{4}' allows for only numeric digits in the pattern of a US phone number. Introduced in EML 2.0.0beta5 Code definition Description of the code associated with the attribute. This element describes the code associated with the attribute. "high" would be the definition for a code of "1" The definition element is from EML 1.4. Text pattern Regular expression pattern constraining the attribute The "pattern" element specifies a regular expression pattern that constrains the set of allowable values for the attribute. This is commonly used to define template patterns for data such as phone numbers where the attribute is text but the values are not drawn from an enumeration. If the pattern field is empty or missing, it defaults to '.*', which matches any string, including the empty string. Repeated pattern elements are combined using logical OR. The regular expression syntax is the same as that used in the XML Schema Datatypes Recommendation from the W3C. '[0-9a-zA-Z]' matches simple alphanumeric strings. The pattern element was introduced into EML 2.0.0beta5. Source of text domain The name of the source for this text domain. The name of the source from which this text domain and its associated definition are drawn. This is commonly used for identifying standard coding systems, like the FIPS standard for postal abbreviations for states in the US. In other cases, the coding may be the researcher's customized way of recording and classifying their data, and no external "source" would exist. ISO country codes Introduced in EML 2.0 Numeric Domain Numeric domain of attribute specifying allowed value range This element specifies the minimum and maximum values of a numeric attribute. These are theoretical or expected values, and not necessarily the actual minimum and maximum occurring in a given data set. The numericDomain was introduced into EML 1.4 as rangeDomain Minimum numeric range Minimum numeric range of attribute This element specifies the minimum value range of numeric attribute. The minimum element was introduced into EML 1.4. Maximum numeric range Maximum numeric range of attribute This element specifies the maximum value range of numeric attribute. The maximum element was introduced into EML 1.4. Character for missing value Character for missing value in the data of the field This element is to specify missing value in the data of the field. The missingValueCode was introduced into EML 1.4. Precision Number of significat digits after the floating point. If data of that field are of floating point storage type this element specifies the number of significat digits after the floating point. any integer number The precision element was introduced into EML 1.4.