k-Wave Toolbox

makeCircle

Create a binary map of a circle within a 2D grid

Syntax

circle = makeCircle(Nx, Ny, cx, cy, radius)
circle = makeCircle(Nx, Ny, cx, cy, radius, arc_angle)
circle = makeCircle(Nx, Ny, cx, cy, radius, arc_angle, plot_circle)

Description

makeCircle creates a binary map of a circle or arc (using the midpoint circle algorithm) within a two-dimensional grid (the circle position is denoted by 1's in the matrix with 0's elsewhere). A single grid point is taken as the circle centre thus the total diameter will always be an odd number of grid points. The plot that is displayed after calling makeCircle(128, 128, 64, 64, 30, (215/180)*pi, true) is given below.

Inputs

`Nx, Ny`	size of the 2D grid [grid points]
`cx, cy`	centre of the circle [grid points], if set to 0, the centre of the grid is used
`radius`	circle radius [grid points]

Optional Inputs

`arc_angle`	arc angle for incomplete circle [radians] (default = `2*pi`)
`plot_circle`	Boolean controlling whether the circle is plotted using `imagesc` (default = false)

Outputs

circle

2D binary map of a circle