Definition

A Multidimensional Interface can be defined over n-dimensional resources, which are RDF resources with n properties whose ranges are strict linearly ordered sets.

A Multidimensional Interface on a given dataset is a collection of interfaces containing the following elements:

Range Fragment

A Linked Data Fragment that has an interval as selector, which apply to dimensional resources at one of its n dimensions.

Range Gate

A Linked Data interface on which a client can find out how to select a certain Range Fragment by interval.

Range Interval

The selected interval has a lower (incl) and an upper bound (excl)

[X,Y[

which describe a Range Fragment

hypermedia controls

A Range Gate MUST contain hypermedia controls that allow to retrieve Range Fragments of the given dataset. This MUST either be provided as a form that allows to choose the initial and final elements of the selector's interval.

A Range Gate MAY contain additional hypermedia controls. The IRIs of data, metadata, and control triples entities SHOULD be dereferenceable.

A Range Fragment MAY contain hypermedia links to more selective Range Gates on that fragmented subset of the original dataset.

A Range Fragment of a dataset is fully determined and identified by its triple pattern selector and interval selector. This interval selector consists of two components initial and final which form a interval. The initial MUST either be a variable, an ordinal literal or an ordinal IRI; the final MUST either be a variable, an ordinal literal or an ordinal IRI; These components MUST NOT be blank nodes.

The above constraints define the document type of a Multidimensional Interface. The following sections and explain this in more detail.

Multidimensional Interfaces are not bound to a specific syntax because different methods can be used to represent its data, metadata, and controls. The server MUST, however, support at least one RDF-based representation that MUST allow for triples to be represented. For allowing clients to correctly parse requests Multidimensional Interfaces, servers MUST indicate the correct MIME type when sending responses.

Range Fragment

A Range Fragment is a Linked Data Fragment of a dataset. This fragment is defined by a certain interval and a dimensional resource over which the interval is defined. This fragmentation is done for exactly one dimension of the dimensional resource over which the Range Fragment is defined.

The dimensional resource type GPS position could be fragmented by longitude and can therefore have several Range Fragments which consist of all dimensional resources that are within a certain longitudal range.

A Range Fragment MAY define a link to a more selective Range Gate as given in the following example:

<http://example.org/range-fragment-0-100>
        mdi:hasRangeGate <http://example.org/range-fragment-0-100/range-gate>.

Such a more selective Range Gate starts from the given Range Fragment as the datasource, and allows further fragmentation of that datasource.

Range Gate

A Range Gate is a Linked Data Fragment that exposes Range Fragments.

Each Range Fragment described in this Range Gate MUST define the following metadata:

• a rdf:type mdi:RangeFragment,
• an mdi:initial describing the lower bound of the interval, including this value, and
• an mdi:final describing the upper bound of the interval, excluding this value.

As given in this example:

<http://example.org/range-fragment-0-100>
        a mdi:RangeFragment;
        mdi:initial "0"^^xsd:integer;
        mdi:final "100"^^xsd:integer.

The Range Gate MAY provide a control to select Range Fragments by providing an interval. This Range Gate control, if provided, MUST be expressed as a form in the Hydra Core Vocabulary [[!HYDRA-CORE]] using triples in the controls graph.

<http://example.org/range-gate>
        a mdi:RangeGate;
        hydra:search [
            hydra:template "http://example.org/range-gate{?initial,final}";
            hydra:mapping  [ hydra:variable "initial"; hydra:property mdi:initial ],
                           [ hydra:variable "final"  ; hydra:property mdi:final ]
        ].

The interval selector is used to lookup all Range Fragments that overlap or are within with the selected interval. The selected interval must be interpreted as starting from initial, including initial up until final, excluding final.

Not providing the initial or final parameter, means that search interval has no limit for that element. If we for example only provide initial and omit final, the Range Gate MUST provide all elements starting from initial. If we only provide final and omit initial, the Range Gate MUST provide all elements until initial.