Trends comes with a handy function getAround. For each point, it returns an array with the surrounding values. This is useful to measure derivatives or max/min/averages... with standard Javascript
getAround(name, countBefore, countAfter)
name: the name of the parameter as string
countBefore: the count of samples to get before the current point
countAfter: the count of samples to get after the current point
// smothes the trend by averaging the last 4 samples. Current value is 9.1// getAround returns ["2.6", "11.4", "2.6", "9.1"]if(DELTA_PACK_P>0){returngetAround("DELTA_PACK_P",3,0).mean();}
Be careful as the name of the parameter is a string. If you do not mention the parameter as a variable in the formula, then WILCO will not fetch it from the database.
The following would not work
returngetAround("DELTA_PACK_P",20,0).mean();
In those simple cases, you will have to mention explicitely the variable, for example like this: