===== Primitive: Convolution with set of triangles =====

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

**Call**: hfConvTriangle(x,vect,S,T);

**Parameters**:

x - point coordinates

vect - coordinate array for vertices of triangles (9 elements for each)

S - array of kernel width control parameters for each triangle

T - threshold

**Test file**: [[http://hyperfun.org/convtri.hf|convtri.hf]]