Smooth g Delete offset jumps

When your plot halfway jumps to another offset value and continues from there, you can compensate for that jump with this function. You have to give the maximum absolute Y jump. If the plot exceeds this jump at a certain point, the jump value will be subtracted from all following data points. If the plot jumps up, and later jumps back, the shifted portion is put back into place while the surrounding portions are left untouched.. For noisy plots you can select a width higher than 1, then the jumping value will be calculated with a mean value of the last few data points before the jump and after the jump.

When you first draw a rectangle, only the data points which fall within the rectangle are processed.

See also this tutorial.