Prev Section 3.17: LoadData Section Up Section 3.17: LoadData Section Subsection 3.17.2: The math controller Next
3.17.1 The loadcurve controller
A loadcurve controller is defined by the loadcurve type. Each loadcurve is defined by repeating the point element for all data points:
<load_controller id="1" type="loadcurve">
<interpolate>LINEAR</interpolate>
<extend>CONSTANT</extend>
<points>
<point> 0, 0 </point>
...
<point> 1, 1 </point>
</points>
</loadcurve>
For a loadcurve, the type is optional, since it is the default controller if the type attribute is omitted.
The id attribute is the loadcurve number and is used in other sections of the input file as a means to reference this curve.
The optional parameters interpolate and extend define how the value of the loadcurve is interpolated from the data points. The interpolate defines the interpolation function and extend defines how the values of the loadcurve are determined outside of the interval defined by the first and last data point. The following tables list the possible values. The default values are marked with an asterisk (*).
| interpolate | Description |
| STEP | Use a step interpolation function |
| LINEAR* | Use a linear interpolation function |
| SMOOTH | The values are interpolated using a cubic polynomial. |
The different values for the interpolate parameter of load curves
| Extend | Description |
| CONSTANT* | The value of the curve is the value of the closest endpoint |
| EXTRAPOLATE | The value is extrapolated linearly from the endpoints |
| REPEAT | The curve is repeated |
| REPEAT OFFSET | The curve is repeated but offset from the endpoints |
The different values for the extend parameter of the load curve.