| 摘要 |
A cluster of features are plotted against x and y axes to produce a graph. In order to view an area of the display which is of particular interest the user clicks the mouse pointer at a point on the x axis which causes a vertical cursor line to be displayed, as shown. Moving the mouse to the left or right causes a second vertical cursor line to be dragged along the x axis to select a section which is to be displayed in greater detail. The display is then redrawn with the x axis re-scaled to the selected section. At the same time, the y axis is re-scaled to include all the features within the selected section plus a small margin 5% above and below the maximum and minimum y values. The display can be re-scaled an unlimited number of times, and the parameters of each zoom are stored in memory so that any of the enlargements can be undone by clicking the right mouse button. By clicking an Up button the user can add 10% to the margin at the top of the display, and clicking the Down button adds 10% to the bottom of the display. |
