a relationship between two GO::Model::Terms
relationships can be thought of as statements or sentences of the form
SUBJECT-TERM PREDICATE OBJECT-TERM
"dog" IS_A "animal" "G-Protein coupled receptor" IS_A "transmembrane receptor"
Statements have a subject (i.e. the subject of the sentence/statement), a predicate/relationship-type and an object (i.e. the object of the sentence/statement)
Relationships can also be seen as arcs in a directed graph, with the subject being equivalent to the child, and the object equivalent to the parent. The arc is labeled with the predicate/relationship-type.
A Relationship object currently does not contain an actual pointer to a GO::Model::Term object. Instead it stores the ID of that term. This is intended to be used in conjunction with the Graph object, or with the database.
Title : subject_acc Usage : $obj->subject_acc($newid) Usage : $currid = $obj->subject_acc() Synonyms: subj_acc, acc2, child_acc Function: gets or sets the identifier for the child/subject term Example : Returns : value of subject_acc (string) Args : on set, new value (string)
All Relationships can be thought of "subject-predicate-object" statements. The statement is *about* the subject, and states something about the relationship *to* the object.
For example, the if we have a Relationship:
cell ^ | | [part_of] | cell nucleus
This is a statement about cell nuclei in general, so "cell nucleus" is the subject (sometimes called the child node). The Relationship tells us that all cell nuclei are part_of some cell, so the object of the relationship (sometimes called the parent node) is "cell"
Title : object_acc Usage : $obj->object_acc($newid) Usage : $currid = $obj->object_acc() Synonyms: obj_acc, acc1, parent_acc Function: gets or sets the identifier for the parent/object term Example : Returns : value of object_acc (string) Args : on set, new value (string) See Also: subj_acc
Title : type Usage : $obj->type($newval) Usage : $currval = $obj->type() Synonyms: Function: gets or sets the relationship type (a string) Example : Returns : value of type (string) Args : on set, new value (string)
Currently any string is allowed; in future the type string may be constrained to come from a controlled vocabulary of relationship types