With this transformation a gradient of a timeserie can be calculated: (y1-y0) / (t1-t0). This is the change in the value per time unit (currently seconds).
<transformation id="Calculate_the_gradient">
<gradient>
<firstOrder>
<inputVariable>
<variableId>InputTimeSeries</variableId>
</inputVariable>
<outputVariable>
<variableId>OutputTimeSeries</variableId>
</outputVariable>
</firstOrder>
</gradient>
</transformation>
A nice example should be added
