Max
See javadoc - uk.gov.gchq.gaffer.operation.impl.compare.Max
Available since Gaffer version 1.0.0
Extracts the maximum element based on provided Comparators
Required fields
The following fields are required:
- comparators
Examples
Max count
Using this directed graph:
--> 4 <--
/ ^ \
/ | \
1 --> 2 --> 3
\
--> 5
Java
JSON
Full JSON
Python
final OperationChain<Element> opChain = new OperationChain.Builder()
.first(new GetElements.Builder()
.input(new EntitySeed(1), new EntitySeed(2))
.build())
.then(new Max.Builder()
.comparators(new ElementPropertyComparator.Builder()
.groups("entity", "edge")
.property("count")
.build())
.build())
.build();{
"class" : "OperationChain",
"operations" : [ {
"class" : "GetElements",
"input" : [ {
"class" : "EntitySeed",
"vertex" : 1
}, {
"class" : "EntitySeed",
"vertex" : 2
} ]
}, {
"class" : "uk.gov.gchq.gaffer.operation.impl.compare.Max",
"comparators" : [ {
"class" : "ElementPropertyComparator",
"property" : "count",
"groups" : [ "entity", "edge" ],
"reversed" : false
} ]
} ]
}{
"class" : "uk.gov.gchq.gaffer.operation.OperationChain",
"operations" : [ {
"class" : "uk.gov.gchq.gaffer.operation.impl.get.GetElements",
"input" : [ {
"class" : "uk.gov.gchq.gaffer.operation.data.EntitySeed",
"vertex" : 1
}, {
"class" : "uk.gov.gchq.gaffer.operation.data.EntitySeed",
"vertex" : 2
} ]
}, {
"class" : "uk.gov.gchq.gaffer.operation.impl.compare.Max",
"comparators" : [ {
"class" : "uk.gov.gchq.gaffer.data.element.comparison.ElementPropertyComparator",
"property" : "count",
"groups" : [ "entity", "edge" ],
"reversed" : false
} ]
} ]
}g.OperationChain(
operations=[
g.GetElements(
input=[
g.EntitySeed(
vertex=1
),
g.EntitySeed(
vertex=2
)
]
),
g.Max(
comparators=[
g.ElementPropertyComparator(
groups=[
"entity",
"edge"
],
property="count",
reversed=False
)
]
)
]
)Result:
Java
JSON
Entity[vertex=1,group=entity,properties=Properties[count=<java.lang.Integer>3]]{
"class" : "uk.gov.gchq.gaffer.data.element.Entity",
"group" : "entity",
"vertex" : 1,
"properties" : {
"count" : 3
}
}Max count and transient property
Using this directed graph:
--> 4 <--
/ ^ \
/ | \
1 --> 2 --> 3
\
--> 5
Java
JSON
Full JSON
Python
final OperationChain<Element> opChain = new OperationChain.Builder()
.first(new GetElements.Builder()
.input(new EntitySeed(1), new EntitySeed(2))
.view(new View.Builder()
.entity("entity", new ViewElementDefinition.Builder()
.transientProperty("score", Integer.class)
.transformer(new ElementTransformer.Builder()
.select("VERTEX", "count")
.execute(new ExampleScoreFunction())
.project("score")
.build())
.build())
.edge("edge", new ViewElementDefinition.Builder()
.transientProperty("score", Integer.class)
.transformer(new ElementTransformer.Builder()
.select("DESTINATION", "count")
.execute(new ExampleScoreFunction())
.project("score")
.build())
.build())
.build())
.build())
.then(new Max.Builder()
.comparators(
new ElementPropertyComparator.Builder()
.groups("entity", "edge")
.property("count")
.reverse(false)
.build(),
new ElementPropertyComparator.Builder()
.groups("entity", "edge")
.property("score")
.reverse(false)
.build()
)
.build())
.build();{
"class" : "OperationChain",
"operations" : [ {
"class" : "GetElements",
"input" : [ {
"class" : "EntitySeed",
"vertex" : 1
}, {
"class" : "EntitySeed",
"vertex" : 2
} ],
"view" : {
"edges" : {
"edge" : {
"transientProperties" : {
"score" : "Integer"
},
"transformFunctions" : [ {
"selection" : [ "DESTINATION", "count" ],
"function" : {
"class" : "ExampleScoreFunction"
},
"projection" : [ "score" ]
} ]
}
},
"entities" : {
"entity" : {
"transientProperties" : {
"score" : "Integer"
},
"transformFunctions" : [ {
"selection" : [ "VERTEX", "count" ],
"function" : {
"class" : "ExampleScoreFunction"
},
"projection" : [ "score" ]
} ]
}
}
}
}, {
"class" : "uk.gov.gchq.gaffer.operation.impl.compare.Max",
"comparators" : [ {
"class" : "ElementPropertyComparator",
"property" : "count",
"groups" : [ "entity", "edge" ],
"reversed" : false
}, {
"class" : "ElementPropertyComparator",
"property" : "score",
"groups" : [ "entity", "edge" ],
"reversed" : false
} ]
} ]
}{
"class" : "uk.gov.gchq.gaffer.operation.OperationChain",
"operations" : [ {
"class" : "uk.gov.gchq.gaffer.operation.impl.get.GetElements",
"input" : [ {
"class" : "uk.gov.gchq.gaffer.operation.data.EntitySeed",
"vertex" : 1
}, {
"class" : "uk.gov.gchq.gaffer.operation.data.EntitySeed",
"vertex" : 2
} ],
"view" : {
"edges" : {
"edge" : {
"transientProperties" : {
"score" : "java.lang.Integer"
},
"transformFunctions" : [ {
"selection" : [ "DESTINATION", "count" ],
"function" : {
"class" : "uk.gov.gchq.gaffer.doc.operation.function.ExampleScoreFunction"
},
"projection" : [ "score" ]
} ]
}
},
"entities" : {
"entity" : {
"transientProperties" : {
"score" : "java.lang.Integer"
},
"transformFunctions" : [ {
"selection" : [ "VERTEX", "count" ],
"function" : {
"class" : "uk.gov.gchq.gaffer.doc.operation.function.ExampleScoreFunction"
},
"projection" : [ "score" ]
} ]
}
}
}
}, {
"class" : "uk.gov.gchq.gaffer.operation.impl.compare.Max",
"comparators" : [ {
"class" : "uk.gov.gchq.gaffer.data.element.comparison.ElementPropertyComparator",
"property" : "count",
"groups" : [ "entity", "edge" ],
"reversed" : false
}, {
"class" : "uk.gov.gchq.gaffer.data.element.comparison.ElementPropertyComparator",
"property" : "score",
"groups" : [ "entity", "edge" ],
"reversed" : false
} ]
} ]
}g.OperationChain(
operations=[
g.GetElements(
view=g.View(
entities=[
g.ElementDefinition(
group="entity",
transient_properties={'score': 'java.lang.Integer'},
transform_functions=[
g.FunctionContext(
selection=[
"VERTEX",
"count"
],
function=g.Function(
class_name="uk.gov.gchq.gaffer.doc.operation.function.ExampleScoreFunction",
fields={}
),
projection=[
"score"
]
)
]
)
],
edges=[
g.ElementDefinition(
group="edge",
transient_properties={'score': 'java.lang.Integer'},
transform_functions=[
g.FunctionContext(
selection=[
"DESTINATION",
"count"
],
function=g.Function(
class_name="uk.gov.gchq.gaffer.doc.operation.function.ExampleScoreFunction",
fields={}
),
projection=[
"score"
]
)
]
)
],
all_edges=False,
all_entities=False
),
input=[
g.EntitySeed(
vertex=1
),
g.EntitySeed(
vertex=2
)
]
),
g.Max(
comparators=[
g.ElementPropertyComparator(
groups=[
"entity",
"edge"
],
property="count",
reversed=False
),
g.ElementPropertyComparator(
groups=[
"entity",
"edge"
],
property="score",
reversed=False
)
]
)
]
)Result:
Java
JSON
Edge[source=1,destination=2,directed=true,matchedVertex=SOURCE,group=edge,properties=Properties[score=<java.lang.Integer>6,count=<java.lang.Integer>3]]{
"class" : "uk.gov.gchq.gaffer.data.element.Edge",
"group" : "edge",
"source" : 1,
"destination" : 2,
"directed" : true,
"matchedVertex" : "SOURCE",
"properties" : {
"score" : 6,
"count" : 3
}
}