[Archive] Difference between Linear and Non-Linear Poisson solver

Message by Ignacio Rocca:
Dear all,
I need to understand the diference between both solvers, in the help there are an explanation but is not enough,can someone explain to me when I can use one or other?, thanks for your help!

Message by Fang Yang:

To my way of thinking, non-linear sovler is suited for LEO(dense plasma), and linear suit for GEO(thin plasma).
does anyone have other opinion?