Plotting Data on a Chart

The Chart component acts as a base for as many curves (series) as the user wishes to display, each having a common time base and allied to one of two scales. The act of placing a curve component within the boundary of the chart, links the two component types together. The user has a number of choices as to how to display the chart on the screen, in terms of its size, background and foreground colours, type and format of scale graticules and grids etc.

The Chart component takes care of the plotting of its contained curves and the automatic scrolling with respect to the time base. It also provides a number of useful facilities for the user to manually select a view of the curve either by using set criteria or by mouse control. Zooming can be performed by holding down the Shift key and dragging a resizable rectangle over the area of interest. Pressing the right hand mouse button will display a menu for redrawing the curve area in a particular way, such as to find the first or last point, or to revert to a normal view from zooming. Selecting a point on the curve area and dragging the cursor to another point will scroll the curve to the new point. Under normal operational conditions, the chart ensures that the last point on a curve can always be seen in such a way as to ensure that the majority of the display shows historical data.

Plotting Data on a Chart

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