| 摘要 |
<p>A cluster of features are plotted against x and y axes to produce a graph. In order toview an area of the display which is of particular interest the user clicks the mousepointer at a point on the x axis which causes a vertical cursor line to be displayed, asshown. Moving the mouse to the left or right causes a second vertical cursor line tobe dragged along the x axis to select a section which is to be displayed in greaterdetail. 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 selectedsection plus a small margin 5% above and below the maximum and minimum yvalues. The display can be re-scaled an unlimited number of times, and theparameters of each zoom are stored in memory so that any of the enlargements canbe undone by clicking the right mouse button. By clicking an Up button the user canadd 10% to the margin at the top of the display, and clicking the Down button adds 10% to the bottom of the display.</p> |
