gen_sample_dataset: Generate Sample Dataset for MVPA Analysis

In bbuchsbaum/rMVPA: Multivoxel Pattern Analysis in R

Generate Sample Dataset for MVPA Analysis

Description

Creates a synthetic dataset for testing and demonstration of MVPA analyses.

Usage

gen_sample_dataset(
  D,
  nobs,
  response_type = c("categorical", "continuous"),
  data_mode = c("image", "surface"),
  spacing = c(1, 1, 1),
  blocks = 5,
  nlevels = 5,
  external_test = FALSE,
  ntest_obs = nobs,
  split_by = NULL,
  na_cols = 0
)

Arguments

D	The data dimension(s): vector of length 2 or 3 for image data, or single number for surface data
nobs	The number of observations
response_type	Either 'categorical' or 'continuous'
data_mode	Either 'image' or 'surface'
spacing	The voxel spacing (default: c(1,1,1))
blocks	The number of 'blocks' in the data (for cross-validation)
nlevels	The number of category levels (only used if response_type='categorical')
external_test	Whether to generate an external test set
ntest_obs	The number of test observations (default: nobs)
split_by	Optional factor for splitting analyses
na_cols	The number of columns to randomly set to NA (default: 0)

Value

A list containing:

dataset

An mvpa_dataset object containing:

• train_data: Training data as NeuroVec or ROISurface

• test_data: Test data (if external_test=TRUE)

• mask: Binary mask indicating valid voxels/vertices

design

An mvpa_design object containing:

• y_train: Response variable for training

• y_test: Response variable for test set (if external_test=TRUE)

• block_var: Block variable for cross-validation

• split_by: Optional splitting factor

Examples

# Generate categorical image dataset
dataset <- gen_sample_dataset(
  D = c(10,10,10),
  nobs = 100,
  response_type = "categorical",
  data_mode = "image",
  blocks = 3,
  nlevels = 2
)

# Generate continuous surface dataset
surf_data <- gen_sample_dataset(
  D = 1000,  # number of vertices
  nobs = 50,
  response_type = "continuous",
  data_mode = "surface"
)

# Generate dataset with external test set
test_dataset <- gen_sample_dataset(
  D = c(8,8,8),
  nobs = 80,
  response_type = "categorical",
  nlevels = 3,
  external_test = TRUE
)

bbuchsbaum/rMVPA documentation built on June 10, 2025, 8:23 p.m.