refineMesh in openfoam
 

Hi
Does anyone know the reson that new points generated by the function refineMesh was neither the middle of two points, nor the middle of the edge? I run refineMesh and found out that the new points between
(0.098 0.0120187 0.001) and (0.1 0.0120299 0.001) is (0.099 0.0116561 0.001).I do not know why.
Thanks
Yu