Class RandomMimic

java.lang.Object

edu.cmu.tetrad.graph.RandomMimic

public final class RandomMimic
extends Object

Flexible MIMIC (Multiple Indicators Multiple Causes) graph generator.

Each group has a single latent factor (rank = 1), parentsPerGroup private measured cause nodes pointing into the latent, and childrenPerGroup measured indicator nodes pointed to by the latent. A random meta-DAG is built over the latents, optionally shared measured parents are added across pairs of latents, and impurities of three kinds can be introduced.

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	RandomMimic.MimicGroupSpec	Specification for a block of MIMIC groups sharing the same structure.

Method Summary

Modifier and Type	Method	Description
static Graph	constructRandomMimic(List<RandomMimic.MimicGroupSpec> specs, Integer metaEdgeCount, int numSharedParents, int numLatentMeasuredImpureParents, int numMeasuredMeasuredImpureParents, int numMeasuredMeasuredImpureAssociations)	Constructs a random MIMIC graph with specified structural constraints.
static List<RandomMimic.MimicGroupSpec>	parseMimicGroupSpecs(String value)	Parses a specification string defining MIMIC group configurations into a list of MimicGroupSpec objects.

Methods inherited from class Object

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

Method Details

constructRandomMimic

public static Graph constructRandomMimic(List<RandomMimic.MimicGroupSpec> specs,
 Integer metaEdgeCount,
 int numSharedParents,
 int numLatentMeasuredImpureParents,
 int numMeasuredMeasuredImpureParents,
 int numMeasuredMeasuredImpureAssociations)

Constructs a random MIMIC graph with specified structural constraints. Each group has a single latent variable, private measured cause nodes (parents of the latent), and measured indicator nodes (children of the latent). A random meta-DAG is built over the latents, shared parents and impurities are added as specified.

Parameters:

specs - list of group specs (countGroups, childrenPerGroup, parentsPerGroup); must not be null or empty.

metaEdgeCount - number of edges in the meta-DAG over latents; if null, ~20% of forward edges are chosen randomly.

numSharedParents - number of new measured nodes each wired as a parent to a randomly chosen pair of latents.

numLatentMeasuredImpureParents - extra latent->measured cross-loadings.

numMeasuredMeasuredImpureParents - directed edges among measured nodes as impurities.

numMeasuredMeasuredImpureAssociations - bidirected associations among measured nodes.

Returns:

the constructed MIMIC graph.

Throws:

IllegalArgumentException - if specs are null/empty, metaEdgeCount is out of range, or numSharedParents > 0 with fewer than 2 latents.

parseMimicGroupSpecs

public static List<RandomMimic.MimicGroupSpec> parseMimicGroupSpecs(String value)

Parses a specification string defining MIMIC group configurations into a list of MimicGroupSpec objects. Each configuration must follow the pattern: countGroups:childrenPerGroup:parentsPerGroup. Multiple configurations should be separated by commas (e.g., 5:6:3, 2:8:4).

Parameters:

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

Returns:

a list of parsed MimicGroupSpec objects.

Throws:

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