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Create a circular ROI

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

The circle is approximated by a regular polygon of n_seg segments.

Usage

at_roi_circle(
  x,
  y,
  r,
  label,
  level = 0L,
  n_seg = 64L,
  ...,
  call = rlang::caller_env()
)

Arguments

x, y

Numeric centre coordinates in image pixels.

r

Positive numeric radius in pixels.

label

Single string class label.

level

Integer pyramid level the coordinates refer to. Default 0.

n_seg

Integer number of polygon segments approximating the circle.

...

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_ellipse(), at_roi_freehand(), at_roi_from_geojson(), at_roi_from_sf(), at_roi_point(), at_roi_polygon(), at_roi_rect()

Examples

r <- at_roi_circle(50, 50, r = 10, label = "nucleus")