remove markov related checks

cmd/internal/markov/absorbing.go

@@ -20,7 +20,6 @@ import (
 	"gonum.org/v1/gonum/graph"
 	"gonum.org/v1/gonum/graph/multi"
 	"gonum.org/v1/gonum/graph/simple"
-	"gonum.org/v1/gonum/graph/topo"
 	"gonum.org/v1/gonum/mat"
 )
 
@@ -37,31 +36,6 @@ func NewAbsorbingMarkovChain() *AbsorbingMarkovChain {
 	return &AbsorbingMarkovChain{WeightedDirectedGraph: multi.NewWeightedDirectedGraph()}
 }
 
-// IsValid returns true if the graph is a valid Markov chain.
-func (g *AbsorbingMarkovChain) IsValid() bool {
-	for nodes := g.Nodes(); nodes.Next(); {
-		u := nodes.Node()
-		if g.outWeightSum(u) != 1 {
-			return false
-		}
-	}
-
-	return true
-}
-
-func (g *AbsorbingMarkovChain) outWeightSum(u graph.Node) float64 {
-	sum := 0.0
-	for nodes := g.From(u.ID()); nodes.Next(); {
-		v := nodes.Node()
-		e := g.WeightedEdge(u.ID(), v.ID())
-		if e != nil {
-			sum += e.Weight()
-		}
-	}
-
-	return sum
-}
-
 // AbsorbingNodes returns all the nodes in the Markov chain identified as
 // absorbing nodes.
 func (g *AbsorbingMarkovChain) AbsorbingNodes() []graph.Node {
@@ -83,35 +57,6 @@ func (g *AbsorbingMarkovChain) AbsorbingNodes() []graph.Node {
 	return absorbingNodes
 }
 
-// IsAbsorbing returns true if the Markov chain is an absorbing chain. This
-// means at least one node is an absorbing node and that every node can reach
-// an absorbing node.
-func (g *AbsorbingMarkovChain) IsAbsorbing() bool {
-	absorbingNodes := g.AbsorbingNodes()
-	if len(absorbingNodes) == 0 {
-		return false
-	}
-
-	for nodes := g.Nodes(); nodes.Next(); {
-		u := nodes.Node()
-		if !g.canBeAbsorbed(u, absorbingNodes) {
-			return false
-		}
-	}
-
-	return true
-}
-
-func (g *AbsorbingMarkovChain) canBeAbsorbed(u graph.Node, absorbingNodes []graph.Node) bool {
-	for _, v := range absorbingNodes {
-		if topo.PathExistsIn(g, u, v) {
-			return true
-		}
-	}
-
-	return false
-}
-
 // AdjacencyMatrix returns the graph's adjacency matrix.
 func (g *AbsorbingMarkovChain) AdjacencyMatrix() *mat.Dense {
 	adj := simple.NewDirectedMatrix(g.Nodes().Len(), 0, 0, 0)

cmd/root.go

@@ -64,14 +64,6 @@ func parse(cmd *cobra.Command, args []string) {
 		panic(err)
 	}
 
-	if !graph.IsValid() {
-		panic("not a Markov chain!")
-	}
-
-	if !graph.IsAbsorbing() {
-		panic("not an absorbing Markov chain!")
-	}
-
 	matrix, err := orderedAdjMatrix(graph)
 	if err != nil {
 		panic(err)