Why does this not work? (logic to calculate an average and save the result)

Questions & Help
1

I am trying to calculate and save the average result of 3 sensor lux values into the logic database.

I have in my room 3 motion sensors which all suply LUX values, now i want to save the average result as logic a value so i created the following flow:

When: sensor value changes (i choose 1 sensor)
Then: calculate logic value.
I choose from list the name of the value to which to save (in my case binnenlux) and then the following as text:
{{[helderheid1]+[helderheid2]+[helderheid3]}/3}
I expected that it would calculate the average of these 3 sensors and save the result as value in binnenlux but nothing happens, the value is empty

info:
[helderheid1] = sensor 1 helderheid etc, choosen from list, blue tag)
binnenlux is the logic name and is number value type

I also tried:
{{[helderheid1]+[helderheid2]+[helderheid3]}:3}
{[helderheid1]+[helderheid2]+[helderheid3]/3}

This is working but is NOT what i want, i want the average not the total:
{[helderheid1]+[helderheid2]+[helderheid3]}

Anyone an idea what i am doing wrong and how to get the average and save this?

2

The actual formula should use parentheses, not brackets:

([helderheid1]+[helderheid2]+[helderheid3])/3
3

Thx, tried it but still no result, the logic value is still empty

(see lowest cards)

https://homey.app/f/qT22xn

and

https://homey.app/f/xCi2xn

both are empty (see lowest card)

4

To be clear, the full value of what you should enter in the flow card should be this:

{{([helderheid1]+[helderheid2]+[helderheid3])/3}}

Here’s an example that works for me:

image

Make sure you don’t have any additional spaces anywhere, those can cause issues.

5

Yep…

I just noticed i now had not the double {{ and }}, added and now it is working!

thx for the help!

6

Is there a command for rounding up or down?
For example something like:

{{round(([helderheid1]+[helderheid2]+[helderheid3])/3),up)}}

7

Logic cards support some (but not all) MathJS functions.

To round up:

{{ceil(([helderheid1]+[helderheid2]+[helderheid3])/3)}}

To round down:

{{floor(([helderheid1]+[helderheid2]+[helderheid3])/3)}}

To round to two decimals:

{{round(([helderheid1]+[helderheid2]+[helderheid3])/3,2)}}
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