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Create an elliptical ROI

Source: R/class-roi.R
at_roi_ellipse.Rd

Create an elliptical ROI

Usage

at_roi_ellipse(
  x,
  y,
  rx,
  ry,
  rotation = 0,
  label,
  level = 0L,
  n_seg = 64L,
  ...,
  call = rlang::caller_env()
)

Arguments

x, y

Numeric centre coordinates in image pixels.

rx, ry

Positive numeric semi-axis lengths in pixels.

rotation

Rotation of the major axis in degrees, clockwise in image orientation. Default 0.

label

Single string class label.

level

Integer pyramid level the coordinates refer to. Default 0.

n_seg

Integer number of polygon segments approximating the ellipse.

...

Additional named attributes stored on the ROI. The reserved names author, source, and id set those fields; all others become user attributes.

call

The calling environment, for error reporting.

Value

An annot_roi with POLYGON geometry.

See also

Other rois: at_roi_area(), at_roi_bbox(), at_roi_centroid(), at_roi_circle(), at_roi_freehand(), at_roi_from_geojson(), at_roi_from_sf(), at_roi_point(), at_roi_polygon(), at_roi_rect()

Examples

r <- at_roi_ellipse(50, 50, rx = 20, ry = 10, rotation = 30, label = "cell")