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Action:
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Creates a subgraph from a given graph using either two integers or a law.
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Filename:
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kern/kern_scm/graph_scm.cxx
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Syntax:
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(graph:subset in-graph {subset-law |
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low-bounds up-bounds})
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Arg Types:
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in-graph
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graph
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subset-law
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law
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low-bounds
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integer
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up-bounds
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integer
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Returns:
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graph
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Description:
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Given an ordered graph, a subgraph may be formed using one of two techniques. One method takes in two integers and the other takes a law pointer.
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in-graph specifies a graph.
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subset-law specifies a law. This extension with
subset-law returns the set of all vertices such that their order evaluates as true along with the all edges that have both of their adjacent vertices evaluating as true orders.
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This extension with
low-bounds and
up-bounds returns a subgraph in one of two ways.
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1.
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If
low-bounds<up-bounds, then the set of all vertices with orders between
low-bounds and
up-bounds is returned along with all edges that have both of their adjacent vertices in this set.
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2.
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If
up-bounds<low-bounds, then the set of all vertices with orders not between
low-bounds and
up-bounds is returned along with all edges that have both of their adjacent vertices in this set.
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Example:
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; graph:subset
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; Create a simple graph
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(define g1 (graph "a-b b-c c-e c-d c-f f-g f-h"))
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;; g1
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(graph:order-from g1 "a")
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;; 4
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(define g2 (graph:subset g1 1 3))
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;; g2
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(define g3 (graph:subset g1 "x>2"))
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;; g3
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(define law1 (law "(x>2)or(x=0)"))
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;; law1
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(define g4 (graph:subset g1 law1))
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;; g4
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