**NAME**

circle

**SYNOPSIS**

circle x0 y0 r [-optional link arguments]

**DESCRIPTION**

circlecreates a circular entity of immersed boundary points.circlerequires three arguments.

- x0 -
xcoordinate of the circle center- y0 -
ycoordinate of the circle center- r - the radius of the circle
circleallows for optional link arguments by interpreting the following options.The default resting length is determined so the points are no more than a distance of

- -A name - indicates this entity is active and provides a name
- -a angle - resting angle at the IB points
- -b bend - bending stiffness at the IB points (default=40000)
- -d distance - initial distance between IB points (default=0.5)
- -N name - provides a name for the entity
- -n number - number of IB points around the circle
- -s stiff - inter-IB-point spring stiffness (default=40000)
- -t tether - tether spring stiffness (default=0)
h/2 apart. The default resting angle is determined so that the circle remains a circle if there is no fluid flow. The tether points are located at the initial IB point positions.

**SEE ALSO**

line,polygon,wheel

**EXAMPLE**

circle 1.0 1.25 0.5 -b 10000

Forms a circle centered at (1,1.25) with a radius of 0.5 and increases the bending stiffness to 10000. The circumference of the circle is , and the resting length is not specified so the number of immersed boundary points set by IBIS is and they are equally spaced on the circle.