Setting the lower y-axis limit Setting the lower y-axis limit
The controls shown above are used to set the lower y-axis limit.
If auto-scale lower y-limit 
is toggled, the minimum y-value of any of the curves in the plot will be used as minimum value. The edit window 
shows the current value. It is possible to type a new value, but remember to validate it by clicking Enter.
The controls 
are used for moving the limit either up or down.