build_mcml: Build MCML from Raw Transition Data

In Nestimate: Network Estimation, Bootstrap, and Higher-Order Analysis

Build MCML from Raw Transition Data

Description

Builds a Multi-Cluster Multi-Level (MCML) model from raw transition data (edge lists or sequences) by recoding node labels to cluster labels and counting actual transitions. Unlike cluster_summary which aggregates a pre-computed weight matrix, this function works from the original transition data to produce the TRUE Markov chain over cluster states.

Usage

build_mcml(
  x,
  clusters = NULL,
  method = c("sum", "mean", "median", "max", "min", "density", "geomean"),
  type = c("tna", "frequency", "cooccurrence", "raw"),
  directed = TRUE,
  compute_within = TRUE,
  actor = NULL,
  action = NULL,
  time = NULL,
  order = NULL,
  session = NULL,
  time_threshold = 900,
  labels = NULL
)

Arguments

x	Input data. Accepts multiple formats: data.frame with from/to columns Edge list. Columns named from/source/src/v1/node1/i and to/target/tgt/v2/node2/j are auto-detected. Optional weight column (weight/w/value/strength). data.frame without from/to columns Sequence data. Each row is a sequence, columns are time steps. Consecutive pairs (t, t+1) become transitions. tna object If x$data is non-NULL, uses sequence path on the raw data. Otherwise falls back to cluster_summary. netobject If x$data is non-NULL, detects edge list vs sequence data. Otherwise falls back to cluster_summary. cluster_summary Returns as-is. square numeric matrix Falls back to cluster_summary. non-square or character matrix Treated as sequence data.
clusters	Cluster/group assignments. Accepts: named list Direct mapping. List names = cluster names, values = character vectors of node labels. Example: list(A = c("N1","N2"), B = c("N3","N4")) data.frame A data frame where the first column contains node names and the second column contains group/cluster names. Example: data.frame(node = c("N1","N2","N3"), group = c("A","A","B")) membership vector Character or numeric vector. Node names are extracted from the data. Example: c("A","A","B","B") column name string For edge list data.frames, the name of a column containing cluster labels. The mapping is built from unique (node, group) pairs in both from and to columns. Limitation: this mode assigns the row's group label to both endpoints, so it only makes sense for edge lists where source and target nodes always share the same group (within-group edges only). For general edge lists where a single node may be source in some rows and target in others, or where source and target belong to different groups, pass an explicit named list (list(G1 = c("N1","N2"), ...)) or a two-column data frame data.frame(node, group) instead. NULL Auto-detect from netobject$nodes or $node_groups (same logic as cluster_summary).
method	Aggregation method for combining edge weights: "sum", "mean", "median", "max", "min", "density", "geomean". Default "sum". For raw sequence/event-log inputs the function is counting observed transitions, so "sum" is the only interpretation that preserves the count semantics – the other methods are useful when aggregating weighted edge lists or pre-existing weight matrices, where each row already represents a measurement rather than a single observation.
type	Post-processing of the aggregated count matrix. One of: "tna" (default) Row-normalize so each row sums to 1 (first-order Markov transition probabilities). "raw" Return the un-normalized count matrix. "frequency" Explicit alias of "raw" – identical raw count construction (kept as a synonym for callers using frequency-network terminology). "cooccurrence" Symmetrize the matrix (undirected co-occurrence). "semi_markov" is not accepted: the package does not implement a semi-Markov / holding-time construction, so passing it errors rather than silently aliasing "tna".
directed	Logical. If TRUE (default), treat transitions as directed. If FALSE, symmetrize sequence- and edge-derived weights before returning raw/frequency weights or before row-normalizing transition probabilities.
compute_within	Logical. Compute within-cluster matrices? Default TRUE.
actor, action, time, order, session, time_threshold	Long-format event-log shortcut. When action is supplied on a data.frame input, the data is passed through prepare() to derive a wide sequence, which is then routed to the existing sequence path. Behaves identically to prepare(...) |> build_network() |> build_mcml().
labels	Optional name -> label remap applied to within-cluster nodes (the macro layer is left untouched because its labels are cluster names). Accepts a 2-column data.frame (name, label), a named character vector c(name = "label"), or a named list. Unmapped names pass through unchanged.

Value

A cluster_summary object with meta$source = "transitions", fully compatible with plot(), as_tna(), and plot().

See Also

cluster_summary for matrix-based aggregation, net_as_tna() to convert to tna objects, plot() for visualization

Examples

# Edge list with clusters
edges <- data.frame(
  from = c("A", "A", "B", "C", "C", "D"),
  to   = c("B", "C", "A", "D", "D", "A"),
  weight = c(1, 2, 1, 3, 1, 2)
)
clusters <- list(G1 = c("A", "B"), G2 = c("C", "D"))
cs <- build_mcml(edges, clusters)
cs$macro$weights

# Sequence data with clusters
seqs <- data.frame(
  T1 = c("A", "C", "B"),
  T2 = c("B", "D", "A"),
  T3 = c("C", "C", "D"),
  T4 = c("D", "A", "C")
)
cs <- build_mcml(seqs, clusters, type = "raw")
cs$macro$weights

Nestimate documentation built on July 11, 2026, 1:09 a.m.