add checks for DAG where relevant in GraphicalModels

[olgakuznetsova]

No description provided.

[olgakuznetsova]

globalMarkov add check for DAG

•	!pairMarkov - Graph or Digraph (checks for DAG)
•	l!ocalMarkov - Graph or Digraph (checks for DAG)
•	!globalMarkov - Graph or Digraph (does not check for DAG)
•	!markovRing - Sequence
•	!gaussianRing- ZZ or Graph or Digraph or MixedGraph (doesn’t check for DAG)
•	!markovMatrices - (Ring,List,List) or (Ring, List) check that it is a Markov ring
•	!covarianceMatrix - Ring, checks that is a Gaussian Ring
•	conditionalIndependenceIdeal - (Ring, List) or (Ring, List, List), checks whether ring is Gaussian or Markov. In the case of (Ring, List, List), only takes Markov rings
•	gaussianParametrization- Ring, checks that is Gaussian ring of MixedGraph without undirected edges
•	gaussianVanishingIdeal - Ring, checks that this is a Gaussian ring go Graph or Digraph or MixedGraph without undirected part
•	!discreteVanishingIdeal - (Ring, Digraph), checks that ring is Markov and the number of vertices is compatible but not that the graph is a Digraph
•	trekSeparation - MixedGraph, checks that there are no undirected edges but does not check that this is a MixedGraph or that both Digraph and Bigraph are present
•	trekIdeal - (Ring,G), where G can be Graph, Digraph or MixedGraph with directed and bidirected edges. Does not check that G has correct type but checks compatibility of variable names in the Ring and G
•	marginMap - (ZZ,Ring), checks that ZZ is compatible with the Ring and that Ring is a MarkovRing
•	inverseMarginMap- (ZZ,Ring), checks that ZZ is compatible with the Ring and that Ring is a MarkovRing
•	hiddenMap - (ZZ,Ring), checks that ZZ is compatible with the Ring and that Ring is a MarkovRing
•	identifyParameters

[roserhp]

• globalMarkov: added check for DAG
• gaussianMatrices
• conditionalIndependenceIdeal: in case we want to add a check, it is enough to add a check in gaussianMatrices
• gaussianVanishingIdeal: already checks directed part is acyclic
• gaussianParametrization
• trekSeparation
• trekIdeal: in case we want to add a check, it is enough to add a check in trekSeparation