Property
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Description
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Class
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- <DRM Property Characteristic>
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Superclass
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Subclass
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Definition
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An instance of this DRM class specifies additional information about
how to use, interpret, or further specify a <DRM Property> instance
or <DRM Table Property Description> instance.
The meaning field specifies
the semantic represented by the <DRM Property Characteristic>
instance.
The characteristic_value field
specifies the data value of the <DRM Property Characteristic>
instance.
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Class diagram
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Figure 6.231 —
DRM_Property_Characteristic
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Inherited field elements
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Field name
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Range
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Field data type
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None |
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Field elements
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Default field values
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Default field values for DRM_Property_Characteristic
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Associated to (one-way) (inherited) |
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Associated to (one-way) |
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Associated by (one-way) (inherited) |
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Associated by (one-way) |
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Associated with (two-way) (inherited) |
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Associated with (two-way) |
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Composed of (two-way) (inherited) |
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Composed of (two-way) |
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Composed of (two-way metadata) (inherited) |
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Composed of (two-way metadata) |
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Component of (two-way) (inherited) |
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Component of (two-way) |
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Constraints
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Clarifications
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None.
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Example(s)
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A <DRM Model> instance classified as ECC_BRIDGE has
a <DRM Property Value> component representing its length. The
<DRM Property Value> component has two
<DRM Property Characteristic> components
to specify maximum length and length precision:
The first <DRM Property Characteristic> component specifies:
The second <DRM Property Characteristic> component specifies:
A <DRM Property Grid> instance containing a
<DRM Table Property Description> component with
meaning =
{ATTRIBUTE,
{EAC_AIR_TEMPERATURE}}
describes air temperature measurements over the specified
region. In some locations, no measurements were taken, so
a sentinel value (deliberately chosen to lie outside the
range of possible data values) is needed to indicate those
locations.
Consequently, the <DRM Table Property Description> instance
for EAC_AIR_TEMPERATURE in this example has a
<DRM Property Characteristic> component
with meaning = EVC_MISSING
and characteristic_value of,
for example, -10000.
Any cell data element for this
<DRM Table Property Description>
instance that has a value of -10000 is therefore
interpreted as meaning that the measurement is missing.
NOTE 1
The <DRM Table Property Description> instance may have other
<DRM Property Characteristic> components provided that they
have different meaning values. For example,
this <DRM Table Property Description> instance may have another
<DRM Property Characteristic> component specifying
EVC_MINIMUM_VALUE.
A <DRM Property Grid> instance containing a
<DRM Table Property Description> component with
meaning =
{ATTRIBUTE,
{EAC_SALINITY}}
describes water salinity data over the region specified
for the grid. However, in this example, part of the grid
lies over land, so that water salinity measurements not
only were not taken there, but make no sense. A sentinel
value (deliberately chosen to lie outside the range of
possible data values) is needed to indicate those locations.
Consequently, the
<DRM Table Property Description>
instance
for EAC_SALINITY in this example has a
<DRM Property Characteristic>
component
with meaning =
EVC_NOT_APPLICABLE and a
characteristic_value of, say, -1.
Any cell data element for this
<DRM Table Property Description>
instance that has a value of -1 is therefore interpreted as
meaning that the measurement is not applicable.
NOTE 2
The <DRM Table Property Description>
instance may have other
<DRM Property Characteristic>
components, provided that they have different
meaning values. For example, this
<DRM Table Property Description>
instance may have another
<DRM Property Characteristic>
component specifying EVC_MINIMUM_VALUE.
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