Formulas

There are three different types of formulas SUM, DIFF, and CUSTOM.

Available variables

There's one input variable available for each input meter: INPUT1, INPUT2, ..., INPUTN. Each input variable is an object containing the following properties:

Property	Type	Description
value	number	The current value of the input event

The formula is run in an environment which provides a couple of helper constants and functions.

Property	Type	Description
Year	number	The current year
Month	number	The current month of the year
Day	number	The current day in month
Hour	number	The current hour
Timestamp	Date	Equal to `new Date(Year, Month, Day, Hour, 0, 0, 0)`
Moment	moment.Moment	Moment.js¹ `moment()` date object for the current timestamp
INPUT[1..N]	Object	The Input provided above

SUM

Will simply sum all the values for a certain timestamp and is equivalent to:

return INPUT1.value + INPUT2.value + ... + INPUTN.value

DIFF

Will subtract all subsequent values and is equivalent to:

return INPUT1.value - INPUT2.value - ... - INPUTN.value

CUSTOM

Allows for a custom formula to be written. The formula can be anything as long as it is valid javascript. The formula will be wrapped in a function before being executed and MUST end with a return statement.

Example valid formula

// We can get the day, month, and year, from variables always available to us.
let factor = 0;
if (Year > 2000) factor = 1;
if (Month > 5) factor = 2;
if (Day > 20) factor = 3;

return (INPUT1.value / INPUT2.value) * factor;

Example invalid formula

While the javascript is valid, it does not return anything and will yield a 0 value.

    function notvalid() {
      return INPUT1.value + INPUT2.value;
    }

Warning

Invalid formulas or formulas taking too long to execute will be terminated and yield a 0 value.lue.

https://momentjs.com/ ↩