Definition: <m>sum{}{}{f®}</m>
f(x) is analytical convolution for an arc with Cauchy kernel [McCormack and Sherstyuk 1998]
r - distance to a skeleton point

Call: hfConvArc(x,center,radius,theta,axis,angle,S,T);

Parameters:

x - point coordinates

center - coordinate array for centers of arcs

radius - array of arcs' radii

theta - array of arcs' angles (from positive x-axis counter-clockwise, 360 for full circle)

axis - array of vectors defining axis of rotation for each arc (placed on local xy-plane)

angle - angles of rotation for arcs around axis of rotation

S - array of kernel width control parameters for each arc

T - threshold

Test file: convarc.hf