Device having touch panel, radar apparatus, plotter apparatus, ship network system, viewpoint changing method and viewpoint changing program

摘要

A touch panel device displays a nautical chart as map data on a display screen. The touch panel device detects a first touch operation on the display screen and a second touch operation on the display screen, the first touch operation being a touch operation of which a position is fixed, the second touch operation being a touch operation of which a position is changed. The touch panel device obtains a rotational axis parallel to the sea surface based on the position of the first touch operation, and rotates a viewpoint of the map data centering on the rotational axis based on a change amount of a distance from the position of the first touch operation to the position of the second touch operation.