Class RandomMim

java.lang.Object

edu.cmu.tetrad.graph.RandomMim

public final class RandomMim
extends Object

Flexible MIM (Multiple Indicator Model) generator.

A "group" is a structural node in the meta-DAG. Each group has rank many latent factors, and childrenPerGroup many measured indicators. For a meta-edge G_i -> G_j, directed edges are added from each latent in G_i to each latent in G_j according to the chosen RandomMim.LatentLinkMode.

Impurities:

• numLatentMeasuredImpureParents: extra latent -> measured cross-loadings
• numMeasuredMeasuredImpureParents: measured -> measured directed edges
• numMeasuredMeasuredImpureAssociations: measured <-> measured bidirected error correlations

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final record	RandomMim.LatentGroupSpec	Specification for a block of groups sharing the same rank and number of children per latent.
static enum	RandomMim.LatentLinkMode	Enum representing the mode of linking between latent nodes across groups in the meta-DAG.

Method Summary

Modifier and Type	Method	Description
static Graph	constructRandomMim(List<RandomMim.LatentGroupSpec> specs, Integer metaEdgeCount, int numLatentMeasuredImpureParents, int numMeasuredMeasuredImpureParents, int numMeasuredMeasuredImpureAssociations, RandomMim.LatentLinkMode latentLinkMode)	Constructs a random meta-graph as a Multiple Indicator Model (MIM) with specified structural constraints.
static List<RandomMim.LatentGroupSpec>	parseLatentGroupSpecs(String value)	Parses a specification string defining latent group configurations into a list of LatentGroupSpec objects.

Methods inherited from class Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

constructRandomMim

public static Graph constructRandomMim(List<RandomMim.LatentGroupSpec> specs,
 Integer metaEdgeCount,
 int numLatentMeasuredImpureParents,
 int numMeasuredMeasuredImpureParents,
 int numMeasuredMeasuredImpureAssociations,
 RandomMim.LatentLinkMode latentLinkMode)

Constructs a random meta-graph as a Multiple Indicator Model (MIM) with specified structural constraints. This method generates latent groups based on the provided specifications, builds a meta-DAG among the groups, and materializes the graph with impurities such as cross-loadings, directed impurities, and bidirectional associations over measured nodes.

Parameters:

specs - the list of specifications describing latent groups, including group ranks and children per group; must not be null or empty.

metaEdgeCount - the number of edges in the meta-DAG over latent groups; if null, a random proportion (~20%) of possible forward edges is chosen instead.

numLatentMeasuredImpureParents - the number of additional latent-to-measured cross-loadings to introduce.

numMeasuredMeasuredImpureParents - the number of directed edges to introduce among measured nodes as impurities.

numMeasuredMeasuredImpureAssociations - the number of bidirectional associations to introduce among measured nodes.

latentLinkMode - the mode of linking latents between groups in the meta-DAG.

Returns:

the constructed graph representing the random MIM with all specified constraints and impurities.

Throws:

IllegalArgumentException - if the specifications are null, empty, or malformed, if the number of meta-edges is out of valid range, or if the latentLinkMode is unrecognized.

parseLatentGroupSpecs

public static List<RandomMim.LatentGroupSpec> parseLatentGroupSpecs(String value)

Parses a specification string defining latent group configurations into a list of LatentGroupSpec objects. Each configuration must follow the pattern: countGroups:childrenPerGroup(rank). Multiple configurations should be separated by commas (e.g., 5:3(2), 4:6(1)).

Parameters:

value - the specification string; must not be null or empty.

Returns:

a list of parsed LatentGroupSpec objects.

Throws:

IllegalArgumentException - if the input is null, empty, or any token is malformed.