Create/Edit
Create/Edit
Each datum line must be defined with a unique acronym that is used to identify it in FAST-TCF scripts. The acronym shouldn't contain any spaces.
An optional label that is displayed on the graph next to the datum line can also be defined. The font, size and colour for the label can be defined, as well as the orientation and position of the label relative to the datum line.
datum lines can be defined as
- Constant Y values
- Constant Y2 values
- Constant X values
- Curves of X,Y points
For constant X, Y or Y2 datums, the line will automatically extend to the edges of the graph and the areas either side of the line can be filled using any of the standard T/HIS colours.
For constant datums, an optional second value can be defined, along with a corresponding second label. A third fill colour can be used to fill in between the two datum lines, reducing the need for multiple datums which rely on being drawn in the correct order.
As the datum lines are drawn in the order they are defined, care must be taken when applying fill colours. The following example shows the effect of defining the datums in a different order. Using the optional second value, the following example can actually be made into a single datum with two values, two labels and three fill colours, as in the above image.
| Datum 1 |
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| + | + | |
| Datum 2 |
|
|
| = | = | |
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|
|
In order to define a datum using X,Y points, either each point can be manually added or the points can be copied into the datum from a curve, using the button. This will open a list of curves and allow one to be selected or picked on the screen and the option to copy the curve label is also given. The areas between the curve and the axes can be filled, either above and below or left and right. Note that datum curves are always plotted against the left-hand y-axis scale, even when copied from a curve currently plotted against the right-hand y-axis.
