The ``clip" value is defined as that above which a signal cannot be displayed, because the screen cannot be made brighter. To replot the filtered data with a different clip value, you touch the data in a different place. The clip is taken as 1% more than the maximum of the 30 time points surrounding the pointer.
There are no numbered axes on the data plane because none are needed. As you move the pointer across the data plane, the values of time and space are written near the ends of the axes. These values are more accurate than you could read from numbered axes.