VertexData-class: VertexData

In bbuchsbaum/neurosurf: Data structures and visualization for surface-based neuroimaging data

VertexData

Description

A set of arbitary vertices associated with a data table

Details

The VertexData class provides a flexible way to associate arbitrary data with specific vertices in a brain surface. Unlike ROISurface and similar classes, VertexData does not require or maintain a reference to surface geometry, making it lighter and more versatile for storing and manipulating vertex-specific information.

This class is particularly useful for:

• Storing heterogeneous data (different data types) associated with vertices

• Maintaining analysis results like statistical outcomes for specific vertices

• Tracking vertex-specific annotations or classifications

• Creating lookup tables for vertex properties that can be joined with other data

The data slot contains a data frame where each row corresponds to a vertex in the same order as the indices slot. This structure allows storing multiple attributes of different types (numeric, character, logical) for each vertex, and facilitates standard data frame operations like filtering, sorting, and joining.

Slots

indices

the node indices

data

the associated table with nrow(data) == length(indices)

Examples

# Create a set of vertex indices
vertex_indices <- c(10L, 25L, 50L, 100L, 200L)

# Create a data frame with information for each vertex
# Each row corresponds to one vertex in the same order as indices
vertex_data <- data.frame(
  value = c(0.5, 1.2, 0.8, 1.5, 0.3),
  label = c("A", "B", "A", "C", "B"),
  significant = c(TRUE, FALSE, TRUE, TRUE, FALSE)
)

# Create the VertexData object
vd <- new("VertexData",
         indices = vertex_indices,
         data = vertex_data)

# Access the data
# vd@data$value
# vd@data$label[vd@data$significant]
# vd@indices[vd@data$label == "A"]

bbuchsbaum/neurosurf documentation built on June 10, 2025, 8:22 p.m.