Label Cards showing results of a math function

[rowellj79 (Justin Rowell)]

Hello,

I am attemping to get a label card to show the result of a mathematical formula, a very simple one.

I keep an offset variable that sets a thermostat at a regular offset from my house thermostat. so if I set my house to 70 degrees, (and the room offset is 2 degrees) the room thermostat will be 68 degrees. I have a script that takes care of all that and turns the heat on at that, then off when it reaches 3 degrees above that point.

I want a card to show me this setting, rather than the house setting or the offset. these are the label expressions that I have tried so far:

=items.Housetempset.state - items.BackBedroomTemperatureOffset.state

and

=Math.subtract(items.Housetempset.state, items.BackBedroomTemperatureOffset.state)

I am missing something and so far have not found an example to help me understand what I need. neither of these expressions work, and only give me a - in the label card.

Any help or ideas would be appreciated.

Thank you,

[JustinG]

See this recent discussion:

[Solved] Actions in custom widgets - update item

Your volume channel may accept INCREASE and DECREASE commands, in which case you won’t have to dynamically define anything. If the channel does not, or you want increments that are a different size than the binding defined increases and decreases, then you’ll need to use an expression to build the numerical command. To build the command you only need to remember one important thing: the state that’s returned from the items object is a string not a number (so you can’t do math until you fix tha…

[rowellj79 (Justin Rowell)]

@rowellj79

items.Housetempset.state - items.BackBedroomTemperatureOffset.state

That was it. This is the answer:

=Number.parseInt(items.Housetempset.state) - Number.parseInt(items.BackBedroomTemperatureOffset.state)