Plot a 2D stick-figure skeleton

Draws a single frame from a PhysioExperiment as a 2D stick figure by projecting 3D marker positions onto an anatomical plane.

Usage

plotSkeleton(
  pe,
  skeleton,
  frame = 1,
  plane = c("sagittal", "frontal", "transverse"),
  show_labels = FALSE,
  show_confidence = FALSE,
  point_size = 3,
  segment_color = "gray40",
  title = NULL
)

Arguments

pe

A PhysioExperiment object with position_x, position_y, and position_z assays (columns named by keypoint label).

skeleton

A SkeletonModel object whose keypoint labels match column names in the position assays.

frame

Integer frame (row) index to plot (default 1).

plane

Anatomical plane for projection: "sagittal" (drop X), "frontal" (drop Y), or "transverse" (drop Z).

show_labels

Logical; annotate markers with their labels.

show_confidence

Logical; color markers by confidence if a confidence assay is present.

point_size

Marker point size (default 3).

segment_color

Color for bone segments (default "gray40").

title

Plot title. If NULL, auto-generated.

Value

A ggplot object.

References

Wickham H (2016). "ggplot2: Elegant Graphics for Data Analysis." Springer.

Winter DA (2009). "Biomechanics and Motor Control of Human Movement." 4th ed. John Wiley & Sons.

See also

plotSkeletonSequence() for multi-frame faceted display, plotSkeletonOverlay() for overlaid motion visualization, plotSkeleton3D() for pseudo-3D rendering, projectTo2D() for coordinate projection utilities.

Examples

sk <- define_skeleton("BODY_25")
labels <- sk$keypoints$label
set.seed(42)
nk <- length(labels); nf <- 10
mk <- function(b) matrix(rep(b, each = nf), nf)
px <- mk(rnorm(nk, 0, 0.3)); py <- mk(rnorm(nk, 0, 0.3))
pz <- mk(seq(1.8, 0, length.out = nk))
colnames(px) <- colnames(py) <- colnames(pz) <- labels
pe <- PhysioExperiment(assays = S4Vectors::SimpleList(
    position_x = px, position_y = py, position_z = pz),
  colData = S4Vectors::DataFrame(label = labels, type = rep("keypoint", nk)),
  samplingRate = 30)
plotSkeleton(pe, sk, frame = 1)