Add a "Computed Value" helper

Feature Requests
1

It would be very helpful to be able to create a numeric automation helper whose value (numeric state) could be calculated whenever needed. Basically it would be a template created via the visual editor.

The createion dialog would look something like:

Name:

integer [ ] float [ ]
Min value (optional)

Max value (optional)

Base value:

Operator (Condition, plus, minus, multiply, divide)

so for example you could have Base Value 0, then click on Operator, select Plus, then Value appears,
here I can put in a constant or a numerical state (e.g temperature), then I can add another operator in the same group or start another group. e.g

Base Value: 0
------------------------
  Operator: Plus
  Value: numeric_state
  Entity: temperature_sensor
  Operator: Divide
  Value: 10
------------
  ADD ANOTHER OPERATOR
-------------
-------------
  Operator: Conditional
  Condition: after sunset
  Operator: Plus
  Value: 1.5
------------
  ADD ANOTHER OPERATOR
-------------

ADD ANOTHER OPERATOR

which would create a template sensor, something like:
value_template: "{{ (states(‘sensor.temperature_sensor’) | float / 10.) + (%if% after_sunset}(1.5){%endif%}}}

or whatever the syntax is supposed to be. Or maybe what would be better, do it in YAML, like:

value:
  - operator: plus
    value: 
      numeric_state:
      entity: sensor_temperature_sensor
      operator: divide
       value: 10.
- operator: condition
    condition: after_sunset
      operator: plus
        value: 1.5
2

This does what you want, though slightly differently, it generates the equation from a set of points:

3

Interesting suggestion, but it is not quite what I need, the compensation value cannot be calculated just from the sensor value. It depends on other factors, for example the temperature sensor is not 100% accurate, but the error is somewhat random, then there may be other factors, like whether the door is open and if so how large a gap, as well as the temperature of the connecting space, and further, the fact that the temperature sensor is located on one side of the space whereas I generally remain on the other side. Actually, what I am going to start doing is to note down all the times that I need to make a manual adjustment and then see if there is any pattern, taking into account anything else I consider that might have an effect. Empirically, the sensor error seems to be +/- 3 degrees C, if I can reduce that to +/- 1 degree, then that is enough.

4

I think one factor is the outside temperature. So it would be really handy to make a “computed value” helper and just put Condition: numerical_state, Entity: sensor.temp_external, Above: 27.0, Action: ADD, value 1, or in the scheme I envisioned above:

Operator: Conditional
Condition:
numerical_state
entity:
sensor.temp_extern
above: 27.0
Operator: Plus
Value: 1.0

(not meant to be an exact depiction of correct YAML, but just to give an idea)

5

I came up with a better suggestion: Make the Combine Sensors helper be super useful