What is the difference between the Manual and Auto (or Manual/0 and Auto/0) scaling of a graph axis?
When the axis scaling is set to Manual, then the minimum, maximum, and step size for the axis are determined by the current values of the minimum, maximum, and step size (as entered in the respective fields of the Scale Options dialog. If it is set to Auto (i.e., automatic), then the program will automatically determine the scaling based on the range of values to be plotted. The Manual/0 and Auto/0 settings work like Manual and Auto (respectively), except that the steps on the scale will be determined as if they always started from 0.0 and not the minimum of the scale (regardless of whether the value of 0.0 is actually included in the current range of the scale or not). The scaling mode for each axis can also be specified in the General Layout dialog.