DEVICE HAVING TOUCH PANEL, RADAR DEVICE, PLOTTER DEVICE, NETWORK SYSTEM FOR USE ON SHIP, PERSPECTIVE-CHANGE METHOD, AND PERSPECTIVE-CHANGE PROGRAM

摘要

A touch-panel device displays map data, namely a nautical chart, on a display screen. The touch-panel device detects a first touch on the display screen, the touch position of which does not change, and a second touch on the display screen, the touch position of which does change. The touch-panel device determines an axis of rotation parallel to the surface of the ocean on the basis of the position of the first touch and rotates the perspective about said axis of rotation on the basis of the amount of change in the distance from the first touch to the second touch.