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Streamline S7 class

Source: R/streamline.R
streamline.Rd

A streamline represents a single fibre tract. It stores three data compartments:

  • @points — a \(P \times 3\) numeric matrix with column names "X", "Y", and "Z" holding the 3-D coordinates of the \(P\) points along the tract.

  • @point_data — a named list of numeric vectors, each of length \(P\), holding additional per-point scalar attributes (e.g. fractional anisotropy). Coordinates are not stored here.

  • @streamline_data — a named list of scalars (length-1 values of any type) holding per-streamline attributes (e.g. a tract-level weight or mean FA, or a character label).

Usage

streamline(points = NULL, point_data = list(), streamline_data = list())

Arguments

points

A \(P \times 3\) numeric matrix with column names "X", "Y", and "Z" giving the 3-D coordinates of the streamline points.

point_data

A named list of numeric vectors, each of length \(P\), holding additional per-point attributes. Must not include "X", "Y", or "Z" (those live in @points).

streamline_data

A named list of per-streamline scalars (length-1, any type).

Value

A streamline S7 object.

Methods for standard generics

The following methods are defined for streamline objects:

  • format(x, ...): Returns a cli-formatted string describing the streamline object.

  • print(x, ...): Prints the formatted string to the console and invisibly returns x.

Additional properties

@n_points

An integer scalar giving the number of points in the streamline (read-only).

@point_attributes

A character vector of the names of the per-point attributes stored in @point_data (read-only).

@streamline_attributes

A character vector of the names of the per-streamline attributes (read-only).

Examples

# Create a streamline with 5 points and some attributes
sl <- streamline(
  points = cbind(
    X = c(0, 1, 1, 1, 0),
    Y = c(0, 0, 1, 1, 1),
    Z = c(0, 0, 0, 1, 1)
  ),
  point_data = list(FA = c(0.5, 0.6, 0.7, 0.8, 0.9)),
  streamline_data = list(mean_FA = 0.7, label = "CST")
)
sl@n_points         # 5
#> [1] 5
sl@point_attributes # "FA"
#> [1] "FA"
sl@streamline_attributes # c("mean_FA", "label")
#> [1] "mean_FA" "label"  

# format() and print() methods
format(sl)
#> [1] "\n── \033[1m\033[1mObject of class \033[1m`fiber::streamline()`\033[1m with \033[1m5\033[1m points.\033[1m\033[22m ──\n\n\033[36m•\033[39m Point attributes: \033[34m\"FA\"\033[39m\n\033[36m•\033[39m Streamline attributes: \033[34m\"mean_FA\"\033[39m and \033[34m\"label\"\033[39m\n"
print(sl)
#> 
#> ── Object of class `fiber::streamline()` with 5 points. ──
#> 
#> • Point attributes: "FA"
#> • Streamline attributes: "mean_FA" and "label"
#>