[Solved] ESP Easy: 3D valve control with ESP8266 - Outdoor temperature-based heating curve

I want to build a 3D valve controller on the basis of the ESP 8266 and ESP Easy to control the floor temperature. The temperature is to be set according to the heating curve, i.e. take into account the temperatures outside.
In ESP Easy I have set myself a Dummy Device with 4 variables. -20, -10,0,10
I have assigned values to each variable, 30, 28, 26, 24 in turn.
And now in Rules I want to calculate what the temperature should be for the underfloor when it's e.g. -15°C outside.
This is where school knowledge and a formula found on the internet comes in handy.
a=(yb-ya)/(xb-xa)
y=(x-xa)+ya
In my case xa,ya are the values for curve#-20 q xb,yb are the values for curve#-10, the value of x is tempZewn
In my case the code looks like this:
.
I also tried a version with the whole formula in one variable, it didn't return any value. Probably too many brackets.
Well, and in the preview of the executed functions (tools>log) it displays this value. There are only two problems. When the outside temperature is below the value of [curve#-20] it doesn't display the calculated value but the value entered for -20, if I enter 35 the max is 35, if I enter 38 the max is 38, and I want it to count also for temperatures below -20.

And the second thing is the function
.
It does not assign the variable var#4 to the given shuffle.
Even though a few lines further on there is a function


Anyone able to help me out, guide me to the correct track?

And do you have to use Esp Easy ? after all, such a thing, even in the Arduino environment, can be written in a dozen minutes.

Greetings

Yes, I know, I have already written more complicated calculations in the IDE but Easy gives me the possibility to easily preview and edit over the internet and this is not the only function that this driver will perform.
So that leaves ESP Easy for the moment and I need to solve this problem somehow.

bambus94 wrote:

So for the moment ESP Easy remains and I have to solve this problem somehow.

.
In this case it is IMHO best by writing your own plugin for espeasy. Easiest by reworking one of the existing ones.

The problem was solved by meticulously and accurately transcribing the names of the shuffle 1:1. Any mistake in the form of a capital letter instead of a lowercase letter or vice versa resulted in a malfunction.
For example, PWM#pwm did not work and pwm#pwm did.