First of all I Thank you very much. Yes, r is the radius and it is the largest positive root. So, I have used Last instead of First in the definition of fPlot in your code. I don't know why but Last command gives the largest positive root in my notebook and it worked nicely. Now to test this code, I have applied the same for published Article. You don't need to go through the full article but fig 3(a) is the desired result. I am getting almost similar graphs but slightly different. Am I still missing something? If you look at the last graph of fig 3(a) the range should be upto near 0.4 in y axis. But, i am getting upto 0.2.
