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pcds (version 0.1.4)

IndCS.Te.onesixth: The indicator for the presence of an arc from a point to another for Central Similarity Proximity Catch Digraphs (CS-PCDs) - first one-sixth of the standard equilateral triangle case

Description

Returns I(pt2 is in NCS(pt1,t=1)) for points pt1 and pt2, that is, returns 1 if pt2 is in NCS(pt1,t=1), returns 0 otherwise, where NCS(x,t=1) is the CS proximity region for point x with expansion parameter t=1.

CS proximity region is defined with respect to the standard equilateral triangle Te=T(A,B,C)=T((0,0),(1,0),(1/2,3/2)) and edge regions are based on the center of mass CM=(1/2,3/6). Here pt1 must lie in the first one-sixth of Te, which is the triangle with vertices T(A,D3,CM)=T((0,0),(1/2,0),CM). If pt1 and pt2 are distinct and pt1 is outside of T(A,D3,CM) or pt2 is outside Te, it returns 0, but if they are identical, then it returns 1 regardless of their locations (i.e., it allows loops).

Usage

IndCS.Te.onesixth(pt1, pt2)

Value

I(pt2 is in NCS(pt1,t=1)) for pt1 in the first one-sixth of Te, T(A,D3,CM), that is, returns 1 if pt2 is in NCS(pt1,t=1), returns 0 otherwise

Arguments

pt1

A 2D point whose CS proximity region is constructed.

pt2

A 2D point. The function determines whether pt2 is inside the CS proximity region of pt1 or not.

Author

Elvan Ceyhan

See Also

IndCSTe