GGU-GEO-GRAPH: "Edit values in section" menu item

If you only need to correct the values for a portion of the data points, select the parameter to which the modification is to be applied in the dialog box as shown below and then mark the points as described.

In the subsequent dialog box you can decide whether the marked values are added to the constant or the constant is used directly as the new value for these points.

If you need to subtract a constant from a value, enter the constant as negative value and activate the upper switch.