[rrd-users] RRD horizontal line coincides with the X-axis

[Александер Пономарёв]

I have a problem with rrdgraph: when max, min, avg and cur (?) values
of data are equal each other at the whole graphics area, the
horizontal line goes right exactly by the x-axis.
Is there anybody know, what modification key I have to use for shift
the line to the middle of my picture?

Now I use this:
slope_modef, rigid, alt_autoscale_max, alt_autoscale, alt_y_grid,
rigid, units_length, base = 1024.

Thanks!