Preview a SeqPlotR plot as a circos layout — seq_preview

Renders a schematic circular layout — no data required. Each track is shown as a colored arc sector. Rows (defined via direction = "under" / %__%) map to concentric rings from outer to inner; tracks within a row (defined via direction = "right" / %|%) map to arc sectors with angular width proportional to track_width. Ring radial thickness is proportional to the maximum track_height in that row.

Only positional layouts are supported — a plot built with a patchwork layout string has no natural circos interpretation and is rejected.

Usage

seq_preview_circos(
  plot_obj = NULL,
  labels = TRUE,
  colors = NULL,
  start_angle = 90,
  end_angle = -270,
  gap_degrees = 2,
  ring_gap = 0.02,
  outer_radius = 0.45,
  inner_radius = 0.08,
  cx = 0.5,
  cy = 0.5
)

Arguments

plot_obj: A seq_plot object built with the operator chain. Required.
labels: Logical. Draw track_id labels. Default TRUE.
colors: Optional named character vector mapping track IDs to fill colors. Unspecified IDs receive automatic colors.
start_angle: Numeric clock-face degrees where the first sector starts. Default 90 (top). Sectors sweep clockwise (decreasing angle).
end_angle: Numeric clock-face degrees where the last sector ends. Default -270 (full circle = start_angle - 360).
gap_degrees: Numeric blank gap in degrees between sectors of the same ring. Default 2.
ring_gap: Numeric npc blank gap between concentric rings. Default 0.02.
outer_radius: Numeric npc radius of the outermost ring's outer edge. Default 0.45.
inner_radius: Numeric npc radius of the innermost ring's inner edge. Default 0.08.
cx, cy: Numeric npc coordinates of the circle centre. Default (0.5, 0.5).

Value

Named list of polar bounding boxes (invisibly). Each entry is list(theta0, theta1, r0, r1) in clock-face degrees and npc radii, keyed by track ID.

Examples

if (FALSE) { # \dontrun{
p <- seq_plot() %|%
  seq_track(track_id = "Chr1", track_width = 3) %|%
  seq_track(track_id = "Chr2", track_width = 2) %|%
  seq_track(track_id = "Chr3", track_width = 1) %__%
  seq_track(track_id = "Signal") %__%
  seq_track(track_id = "CopyNum")
seq_preview_circos(plot_obj = p)
} # }