Hi MESA users

I want to define a quantity named dr_bar which is the radial interval between the center of two successive zones (like dm_bar) and also a radius named rprime which is defined at center of each zone. I am not sure about the following definitions for rprime and dr_bar

rprime(i)= s% r(i+1) + dr(i) / 2

and
________________

dr_bar( s% nz) = ( dr( s% nz) + dr( s% nz-1) )/2        Or       dr_bar( s% nz) = dr( s% nz) +( dr( s% nz-1) )/2 
dr_bar(j) = ( dr( j ) + dr( j-1) )/2
dr_bar(1)= dr(1) / 2

or      _ _ _ _ _ _ _ _ _ _ _

dr_bar(nz) = dr(nz) / 2
dr_bar(j)= ( dr(j)+dr(j+1) )/2
dr_bar(1)= ( dr(1)+dr(2) )/2
________________

I would be grateful if you could help me.
 


Sheyda Najafi