| 摘要 |
PURPOSE:To set a proper scale by displaying a figure showing the relation between the display range of a map which is currently displayed and a display map after the scale is varied when the display map is varied in scale. CONSTITUTION:A wide-area and a detail key are displayed on the screen after the scale variation and touched to vary the scale, and then a map screen on one of scales is selectable. When one key is continuously pressed, the scale is varied successively and the key touch is quitted when a desired scale is obtained, so that the selected scale is determined. When the scale is determined, the map on the determined scale is drawn. When the map on the corresponding scale is not found, a specific display is made and a map on a 1:40,000 scale is drawn and displayed. For the scale selection, not only a scale bar, but also a frame showing the scale are displayed. Consequently, a user knows which part of the map is displayed by referring to the frame display. |
