A system includes a display, an input device, and a processor. The processor is configured to present to a user, on the display, a GUI that illustrates multiple electrodes disposed on an expandable frame of a multi-electrode catheter, and indicates which of the electrodes is active and which of the electrodes is inactive. The processor is further configured to (a) receive, via the input device first user input that chooses between a single-electrode-selection mode and a fan-selection mode, (b) when in the single-electrode-selection mode, receive via the input device second user input that specifies for activation or deactivation individual ones of the electrodes, and (c) when in the fan-selection mode, receive via the input device third user input that specifies for activation or deactivation an angular sector including two or more of the electrodes, and activate and deactivate the electrodes responsively to the first, second and third user inputs.