Element Definitions:
|
eml-physical |
Content of this field:
|
Description of this field:
|
|
Tooltip:
Physical structure.
Summary:
Physical structure of an entity or entities.
Description:
Physical structure of an entity or entities. This generally is a detailed
description of a text representation that shows how the columns and rows
of a table are represented, or simply the name of a well-known binary or
proprietary format (e.g., Microsoft Excel 2000).
Example:
Lineage:
The eml-physical was introduced into EML 1.4 as eml-file.
|
identifier |
Content of this field:
|
Description of this field:
|
Elements:
|
Required?:
|
How many:
|
Attributes:
|
Required?:
|
Default Value:
|
|
Tooltip:
Unique identifier
Summary:
The unique identifier of this metadata file or object.
Description:
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.
Example:
<identifier system="metacat">nceas.3.2</identifier>
Lineage:
The 'identifier' field is derived from the eml-dataset
meta_file_id filed in EML 1.4.
|
format |
Content of this field:
|
Description of this field:
|
Type: xs:string |
Attributes:
|
Required?:
|
Default Value:
|
|
Tooltip:
File format
Summary:
Contains the name of the format for this file.
Description:
This element contains the name of the file's format.
The file's format is typically ASCII, Unicode, or some
well-known binary format (e.g., Microsoft Excel 2000).
It is recommended to include a
complete MIME type here, such as image/jpeg or text/xml. Note
that this is the format of the physical file itself.
Example:
<format>ASCII</format>
Lineage:
The format element was introduced into EML 1.4.
|
characterEncoding |
Content of this field:
|
Description of this field:
|
Type: xs:string |
Attributes:
|
Required?:
|
Default Value:
|
|
Tooltip:
Character Encoding
Summary:
Contains the name of the chracter encoding used for the data.
Description:
This element contains the name of the character encoding.
This is typically ASCII or UTF-8, or one of the other common encodings.
Example:
<characterEncoding>UTF-8</characterEncoding>
Lineage:
Introduced in EML 2.0
|
size |
Content of this field:
|
Description of this field:
|
Elements:
|
Required?:
|
How many:
|
Attributes:
|
Required?:
|
Default Value:
|
|
Tooltip:
Entity size
Summary:
Describes the physical size of the entity.
Description:
This element contains information of the physical size
of the entity, typically in bytes.
Example:
<entitySize unit="bytes">13</entitySize>
Lineage:
The entitySize was introduced into EML 1.4.
|
authentication |
Content of this field:
|
Description of this field:
|
Elements:
|
Required?:
|
How many:
|
Attributes:
|
Required?:
|
Default Value:
|
|
Tooltip:
Authentication method
Summary:
A value, typically a checksum, used to authenticate that the bitstream
delivered to the user is identical to the original.
Description:
This element describes authentication procedures or
techniques, typically by giving a checksum method (e.g., MD5) and
checksum value for the bytestream.
Example:
<authentication method="MD5">f5b2177ea03aea73de12da81f896fe40</authentication>
Lineage:
The authentication element was introduced into EML 1.4.
|
compressionMethod |
Content of this field:
|
Description of this field:
|
Type: xs:string |
Attributes:
|
Required?:
|
Default Value:
|
|
Tooltip:
Entity's compression method
Summary:
Name ofthe entity's compression method
Description:
This element describes any compression methods used to
compress the entity, such as zip, compress, etc.
Example:
Lineage:
The compressed element was introduced into EML 1.4.
|
encodingMethod |
Content of this field:
|
Description of this field:
|
Type: xs:string |
Attributes:
|
Required?:
|
Default Value:
|
|
Tooltip:
Encoding Method
Summary:
Method used for encoding the entity
Description:
This element describes the entity's encoded method, such as
MIME base64 encoding or binhex encoding.
Example:
Lineage:
The encoded element was introduced into EML 1.4.
|
numHeaderLines |
Content of this field:
|
Description of this field:
|
Type: xs:string |
Attributes:
|
Required?:
|
Default Value:
|
|
Tooltip:
Header lines
Summary:
Header lines in the entity
Description:
Number of header lines or information that prepares data.
Example:
<numHeaderLines>3</numHeaderLines>
Lineage:
The numHeaderLines element was introduced into EML 1.4.
|
recordDelimiter |
Content of this field:
|
Description of this field:
|
Type: xs:string |
Attributes:
|
Required?:
|
Default Value:
|
|
Tooltip:
Record delimiter character
Summary:
Character used to delimit records.
Description:
This element specifies the record delimiter character
when the format is text. The record delimiter is usually a
newline (\n) on UNIX, a carriage return (\r) on MacOS, or
both (\r\n) on Windows/DOS. Multiline records are usually
delimited with two line ending characters, for example on UNIX
it would be two newline characters (\n\n).
Example:
<recordDelimiter>\n\r</recordDelimiter>
Lineage:
The recordDelimiter element was introduced into EML 1.4.
|
maxRecordLength |
Content of this field:
|
Description of this field:
|
Type: xs:string |
Attributes:
|
Required?:
|
Default Value:
|
|
quoteCharacter |
Content of this field:
|
Description of this field:
|
Type: xs:string |
Attributes:
|
Required?:
|
Default Value:
|
|
Tooltip:
Quote character
Summary:
Character used to quote values for delimeter escaping
Description:
This element specifies a character to be used in the entity
for quoting values so that field delimeters can be used within
the value. This basically allows delimeter "escaping". The
quoteChacter is typically a " or '.
Example:
<quoteCharacter>"</quoteCharacter>
Lineage:
The quoteCharacter element was taken from the NBII standard.
|
literalCharacter |
Content of this field:
|
Description of this field:
|
Type: xs:string |
Attributes:
|
Required?:
|
Default Value:
|
|
Tooltip:
Literal character
Summary:
Character used to escape other characters
Description:
This element specifies a character to be used for escaping
character values so that the following character is treated as its literal
value. This allows "escaping" for special characters like quotes, commas,
and spaces when they aren't intended as a delimiter value. The
literalChacter is typically a \.
Example:
<literalCharacter>\</literalCharacter>
Lineage:
Introduced in EML 2.0.
|
fieldStartColumn |
Content of this field:
|
Description of this field:
|
Type: xs:string |
Attributes:
|
Required?:
|
Default Value:
|
|
Tooltip:
Start column
Summary:
The starting column number for a fixed format attribute.
Description:
FixedWidth fields have a set length, thus
the end of the field can always be determined
by adding the fieldWidth to the starting
column number.
Example:
any positive integer, see example in "delimeter" description
Lineage:
Introduced into EML 2.0.
|
fieldWidth |
Content of this field:
|
Description of this field:
|
Type: xs:string |
Attributes:
|
Required?:
|
Default Value:
|
|
Tooltip:
Field width
Summary:
FieldWidth specification for fixed field length.
Description:
FixedWidth fields have a set length, thus
the end of the field can always be determined
by adding the fieldWidth to the starting
column number.
Example:
any positive integer, see example in "delimeter"
description
Lineage:
The fieldWidth element was introduced into
EML 1.4. Semantics changed to work identically to
the NBII DTD.
|
fieldDelimiter |
Content of this field:
|
Description of this field:
|
Type: xs:string |
Attributes:
|
Required?:
|
Default Value:
|
|
Tooltip:
Attribute delimiter
Summary:
The end of the attribute (field) is delimited by a
special character called a field delimiter.
Description:
Variable width format fields (attributes) can vary in their
field length, thus the end of the field is
delimited by a special character called a
field delimiter (typically a comma or a space).
Data sets are generally classified as fixedWidth
format or variableWidth format, but we have
determined that this is actually a per-field
classification because one may encounter
fixedWidth fields mixed together in the same
data file with variableWidth fields.
In our encoding scheme, the start of each field
is assumed to be the column after the last column
of the previous field, or the first column
if this is the first field in the dataset, unless
the starting column is explicity enumerated using the
"fieldStartColumn" element.
The end column for each field is classified
using either a special character delimeter indicated
using the filedDelimiter element,
or a fixed field length indicated by using the "fieldWidth"
element. The delimiter for the last field in the data set can be omitted.
variableWidth fields can vary in their field length, and the end of
the field is delimited by a special character
called a field delimiter, usually a comma or
a tab character. fixedWidth fields have a set
length, and so the end of the field can always
be determined by adding the fieldWidth to the
starting column number. Here is an example:
Assume we have the following data in a data set:
May,100aaaa,1.2,
April,200aaaa,3.4,
June,300bbbb,4.6,
The metadata indicating the physical layout of the 4 fields would include the
following:
<delimiter>,</delimiter>
<fieldWidth>3</fieldWidth>
<fieldWidth>3</fieldWidth>
<delimiter>,</delimiter>
In a strictly fixed format file, the metadata would be slightly different:
May100aaaa1.2
Apr200aaaa3.4
Jun300bbbb4.6
<fieldWidth>3</fieldWidth>
<fieldWidth>3</fieldWidth>
<fieldWidth>4</fieldWidth>
<fieldWidth>3</fieldWidth>
or, one could explicitly describe the starting columns:
<fieldStartColumn>1</fieldStartColumn>
<fieldWidth>3</fieldWidth>
<fieldStartColumn>4</fieldStartColumn>
<fieldWidth>3</fieldWidth>
<fieldStartColumn>7</fieldStartColumn>
<fieldWidth>4</fieldWidth>
<fieldStartColumn>11</fieldStartColumn>
<fieldWidth>3</fieldWidth>
Example:
comma, tab, white space, etc.
Lineage:
The delimiter element was introduced into
EML 1.4. Semantics changed to work identically to
the NBII DTD, and then modified to fit more cases.
|
Attribute Definitions:
|
system |
Type: xs:string
Use: optional
|
Tooltip:
Catalog system
Summary:
The catalog system in which this identifier is used.
Description:
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?
Example:
<identifier system="metacat">nceas.3.2</identifier>
Lineage:
New to EML 2.0.
|
unit |
Use: required
|
Tooltip:
Unit of measurement
Summary:
Unit of measurement for the entity size, typically bytes
Description:
This element gives the unit of measurement for the
size of the entity, and is typically bytes.
Example:
<entitySize unit="bytes">13</entitySize>
Lineage:
The unit was introduced into EML 1.4.
|
method |
Type: xs:string
Use: optional
|
Tooltip:
Authentication method
Summary:
The method used to calculate an authentication checksum.
Description:
This element names the method used to calculate and
authentication checksum that can be used to validate a
bytestream. Typical checksum methods include MD5 and CRC.
Example:
<authentication method="MD5">f5b2177ea03aea73de12da81f896fe40</authentication>
Lineage:
The authentication element was introduced into EML 1.4.
|
Complex Type Definitions:
|
Simple Type Definitions:
|