[SOLVED] Rule: Could not cast humidity [%] to DecimalType

Setup, Configuration and Use Scripts & Rules
1

Hey!

i want to create a rule to dehumidify a cellar with the script of “kisseler S.”. Therefore I wanted to use the outside humidity of openweathermap. Unfortunately, the item “localCurrentHumidity” always contains the unit “%”, which leads to an error when casting.
is the error due to the item or the script?

Failure Log:

Error during the execution of startup rule 'Taupunktberechnung
Außenbereich': Could not cast 76 % to
org.eclipse.smarthome.core.library.types.DecimalType; line 43, column 12, length 41

Item:

Number:Dimensionless localCurrentHumidity "Current atmospheric humidity [%d %unit%]" <humidity> { channel="openweathermap:weather-and-forecast:api:local:current#humidity" }

Rule:

val org.eclipse.xtext.xbase.lib.Functions$Function2<Double, Double, Double> getDewPoint = [
	
	Double Temperature, 
	Double Humidity 
	
	|

	var Double a
	var Double b
	var Double SDD
	var Double DD
	var Double v
	var Double t = Temperature
	var Double h = Humidity
	
	if (t >= 0.0){ // T >= 0 °C
		a = 7.5
		b = 237.3
	} else { // T < 0 °C über Wasser
		a = 7.6
		b = 240.7
	}
	SDD=(6.1078 * Math::pow(10.0, ((a*t)/(b+t))))
	DD = (h/100.0*SDD)
	v = Math::log10((DD/6.107))
	return ((b*v)/(a-v))

]

rule "Taupunktberechnung Außenbereich" // calculation of outdoor dewpoint
when

	Item Aussenbereich_Temperature changed or
	Item localCurrentHumidity changed or
	System started

then

	if ((Aussenbereich_Temperature.state != NULL) && (localCurrentHumidity.state != NULL))
	{

		var t = (Aussenbereich_Temperature.state as DecimalType).doubleValue
		var h = (localCurrentHumidity.state as DecimalType).doubleValue
		
		// OutsideThermometerCombined.sendCommand(String::format("%.1f°C / %.0f%%", t, h))
	
		Aussenbereich_Taupunkt.postUpdate(getDewPoint.apply(t, h))
			
	}

end

rule "Taupunktberechnung Keller" // calculation of basement dewpoint
when

	Item Keller_Temperature received update or
	Item Keller_Humidity received update or
	System started

then

	if ((Keller_Temperature.state != NULL) && (Keller_Humidity.state != NULL))
	{

		var t = (Keller_Temperature.state as DecimalType).doubleValue
		var h = (Keller_Humidity.state as DecimalType).doubleValue
		
		// OutsideThermometerCombined.sendCommand(String::format("%.1f°C / %.0f%%", t, h))
	
		Keller_Taupunkt.postUpdate(getDewPoint.apply(t, h))
			
	}

end

rule "Taupunktdifferenz berechnen" // for statistics: dewpoint difference
when
	Item Keller_Taupunkt changed or
	Item Aussenbereich_Taupunkt changed
then
	var dewpoint_keller = (Keller_Taupunkt.state as DecimalType).doubleValue
	var dewpoint_aussen = (Aussenbereich_Taupunkt.state as DecimalType).doubleValue		
	Taupunkt_Differenz.postUpdate(dewpoint_keller - dewpoint_aussen)
end
2

See Using UoM / QuantityType in rules where used DecimalType Previously - Solved

3

You could always try this.

Keller_Taupunkt.state.replace("%","")

Although I’ve never tried to use .replace to remove a character

4

You coulf try but I guess that’s valid for strings only. But his item is a Number.

5

Oh yeah.

Could it be as simple as defining the item NOT to have the % dimension?

I had to do this with some Temperature items so that they worked in a HabPanel widget.

6

I believe the part in “” is just meant to define the output format so changing that should not affect the data type.

7

thanks to all! the solution finally delivered mstormi.
I had to change:

var h = (localCurrentHumidity.state as DecimalType).doubleValue

to

var h = (localCurrentHumidity.state as QuantityType<Number>).doubleValue

inside the rule.

3 Likes