Rule with formula seems to blow the rule engine

Setup, Configuration and Use Scripts & Rules
1
  • Platform information: OpenHab 2.5.6 on RPi 4

The following rule completely halts the loading & execution of all the other rules. I read couple comments about double parsing but even after 20 minutes, this rule is still hanging the whole openhab. Any suggestions?

/**
  https://weather.gc.ca/windchill/wind_chill_e.html
  https://rdrr.io/cran/frost/src/R/dewPoint.R
  **/


rule "Humidex Calculation"
    when Item DewPoint changed
then
    var temp = (GardenTemperature.state as Number).doubleValue
    var dewPoint = (DewPoint.state as Number).doubleValue
    var humidex = temp + 0.5555 * (6.11 * Math.exp((5417.753 * ((1/273.16) - (1/(273.15 + dewPoint))))) - 10)
    logInfo("humidex", "Current Temp:" + temp + " Dew:" + dewPoint + " Humidex:" + humidex)
    Humidex.postUpdate(humidex)
end
2

Looks related

3

Are your Items defined with UoM?

4

Incredible… indeed… breaking down the formula was sufficient to make the rule engine working again.

rule "Humidex Calculation"
    when Item DewPoint changed
then
    var temp = (GardenTemperature.state as Number).doubleValue
    var dewPoint = (DewPoint.state as Number).doubleValue
    var expValue = Math.exp((5417.753 * ((1/273.16) - (1/(273.15 + dewPoint)))))
    var humidex = temp + 0.5555 * (6.11 * expValue - 10)
    logInfo("humidex", "Current Temp:" + temp + " Dew:" + dewPoint + " Humidex:" + humidex)
    Humidex.postUpdate(humidex)
end
1 Like
5

Magical, isn’t it. Not so much the (old) rule engine, as the parser/interpreter getting mired in deeply nested maths brackets.

1 Like