function centroid = triangle_centroid ( t )
%*****************************************************************************80
%
%% triangle_centroid() computes the centroid of a triangle.
%
% Discussion:
%
% The centroid of a triangle can also be considered the
% center of gravity, or center of mass, assuming that the triangle
% is made of a thin uniform sheet of massy material.
%
% The centroid of a triangle is the intersection of the medians.
%
% A median of a triangle is a line connecting a vertex to the
% midpoint of the opposite side.
%
% In barycentric coordinates, in which the vertices of the triangle
% have the coordinates (1,0,0), (0,1,0) and (0,0,1), the centroid
% has coordinates (1/3,1/3,1/3).
%
% In geometry, the centroid of a triangle is often symbolized by "G".
%
% Licensing:
%
% This code is distributed under the GNU LGPL license.
%
% Modified:
%
% 30 January 2005
%
% Author:
%
% John Burkardt
%
% Reference:
%
% Adrian Bowyer and John Woodwark,
% A Programmer's Geometry,
% Butterworths, 1983.
%
% Input:
%
% real T(2,3), the triangle vertices.
%
% Output:
%
% real CENTROID(2,1), the coordinates of the centroid.
%
dim_num = 2;
for i = 1 : dim_num
centroid(i,1) = sum ( t(i,1:3) ) / 3.0;
end
return
end