Dear all,
With this snippet:
xlim=c(-126000,500000)
in the current plot, the x-axis appear  in the following tick marks:
-100000, 100000, 300000, ...etc
How can we force a point where x=0 to appear in the plot?
Yielding:
-100000, 0, 100000, 300000, ...etc
               ^
in the x-axis tick marks.
- Gundala Viswanath
Jakarta - Indonesia