Min
See javadoc - uk.gov.gchq.gaffer.operation.impl.compare.Min
Available since Gaffer version 1.0.0
Extracts the minimum element based on provided Comparators
Required fields
The following fields are required:
- comparators
Examples
Min 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 Min.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.Min",
"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.Min",
"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.Min(
comparators=[
g.ElementPropertyComparator(
groups=[
"entity",
"edge"
],
property="count",
reversed=False
)
]
)
]
)Result:
Java
JSON
Edge[source=1,destination=4,directed=true,matchedVertex=SOURCE,group=edge,properties=Properties[count=<java.lang.Integer>1]]{
"class" : "uk.gov.gchq.gaffer.data.element.Edge",
"group" : "edge",
"source" : 1,
"destination" : 4,
"directed" : true,
"matchedVertex" : "SOURCE",
"properties" : {
"count" : 1
}
}Min 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 Min.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.Min",
"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.Min",
"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.Min(
comparators=[
g.ElementPropertyComparator(
groups=[
"entity",
"edge"
],
property="count",
reversed=False
),
g.ElementPropertyComparator(
groups=[
"entity",
"edge"
],
property="score",
reversed=False
)
]
)
]
)Result:
Java
JSON
Entity[vertex=2,group=entity,properties=Properties[score=<java.lang.Integer>2,count=<java.lang.Integer>1]]{
"class" : "uk.gov.gchq.gaffer.data.element.Entity",
"group" : "entity",
"vertex" : 2,
"properties" : {
"score" : 2,
"count" : 1
}
}