'$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 $'
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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.