Compare Analysis Methods on Dynamic Synergy Data (v2) — compare_static_vs

This function uses the v2 dynamic synergy simulator (simulate_dynamic_synergy_data), which provides three orthogonal control axes: spatial structure, temporal coordination, and stability-adaptability. This allows for systematic evaluation of how different motor control strategies affect muscle synergy structures.

Usage

compare_static_vs_dynamic(
  model_types = c("Dynamic_v2"),
  N = 30,
  K = 3,
  r = 3,
  M = 8,
  T_each = 200,
  cluster_sep_spatial = 1,
  cluster_sep_temporal = 1,
  cluster_sep_stability = 1,
  seed = 123,
  output_dir = "results/compare_dynamic_v2",
  n_init = 1,
  use_kmeans_init = FALSE,
  mc_cores = 1
)

Arguments

model_types: Character vector specifying which model types to use. Default is c("Dynamic_v2"). Only "Dynamic_v2" is supported.
N: Number of subjects (time series). Default is 30.
K: True number of clusters. Default is 3.
r: True factor dimension (number of synergies). Default is 3.
M: Number of observed channels (muscles). Default is 8.
T_each: Time-series length per subject. Default is 200.
cluster_sep_spatial: Numeric scalar (0-2) controlling spatial structure differentiation between clusters. Higher values create more distinct spatial modules. Default is 1.0.
cluster_sep_temporal: Numeric scalar (0-2) controlling temporal coordination differentiation between clusters. Higher values create more distinct temporal patterns. Default is 1.0.
cluster_sep_stability: Numeric scalar (0-2) controlling stability-adaptability differentiation between clusters. Higher values create more distinct noise profiles. Default is 1.0.
seed: Random seed for data generation. Default is 123.
output_dir: Directory path where results will be saved. Default is "results/compare_dynamic_v2". The directory will be created if it doesn't exist.
n_init: Number of random initializations for mixture methods. Default is 1.
use_kmeans_init: Logical; if TRUE, also try k-means initialization. Default is FALSE.
mc_cores: Number of cores for parallel computation. Default is 1.

Value

A data frame with the following columns:

model_type: Character string: "Dynamic_v2"
Method: Analysis method name (e.g., "MixtureFA", "SinglePCA")
BIC: Bayesian Information Criterion
ARI: Adjusted Rand Index (clustering accuracy)
SSE: Sum of Squared Errors (reconstruction error)
VAF: Variance Accounted For (1 - SSE/totalSST)
seed: Random seed used for data generation
cluster_sep_spatial: Spatial separation parameter
cluster_sep_temporal: Temporal separation parameter
cluster_sep_stability: Stability separation parameter
N: Number of subjects
K: Number of clusters
r: Number of synergies
M: Number of muscles
T_each: Time series length

Details

The function generates data using the Dynamic_v2 model and applies six analysis methods (SingleFA, SinglePCA, TwoStep_FA, TwoStep_PCA, MixtureFA, MixturePCA) to evaluate their performance.

The function saves results to an RDS file in the specified output directory with filename format results_YYYY-MM-DD.rds.

Data is generated using simulate_dynamic_synergy_data, which creates time-varying synergy activation patterns with three orthogonal control axes: (1) Spatial structure, (2) Temporal coordination, and (3) Stability-Adaptability.

The generated data is analyzed using six methods, allowing comparison of method performance on realistic dynamic synergy data.

Examples

if (FALSE) { # \dontrun{
# Basic comparison with v2 simulator
results <- compare_static_vs_dynamic(
  N = 30, K = 3, r = 3, M = 8, T_each = 200,
  cluster_sep_spatial = 1.0,
  cluster_sep_temporal = 1.0,
  cluster_sep_stability = 1.0,
  seed = 123
)
print(results)

# Compare with high spatial separation
results_spatial <- compare_static_vs_dynamic(
  N = 30, K = 3, r = 3, M = 8, T_each = 200,
  cluster_sep_spatial = 2.0,
  cluster_sep_temporal = 0.5,
  cluster_sep_stability = 1.0,
  seed = 456
)

# Visualize results
library(ggplot2)
ggplot(results, aes(x = Method, y = ARI)) +
  geom_bar(stat = "identity", fill = "steelblue") +
  labs(title = "Method Performance on Dynamic v2 Data")
} # }