Domoticz

hi,

i have a rfx meter counter. Is it possible to get the value 349 tendance water in the dzvents script ? Pierrotori

I believe it is calculated by the highcharts graph module on the webgui part. So not available in dzvents.
You could ofcourse have dzvents calculate a trend based on the values in the database.

if i would like to use the function in dzvents to calculate a trend bases, i suppose i use a sqlite function, is it correct ?

but by default sqlite is not installed

No, sqlite is never needed to do dzvents actions.
You probably need an Domoticz json API param=graph call to get the history data https://wiki.domoticz.com/Domoticz_API/ ... 7s#History
From that data you can calculate the trend with dzvents/lua. There will probably be Lua functions for that.

very good, thanks a lot i continue to update the dzvents script

i try this , but no tendance water in the result of http

As said before, the web graph module highcharts that Domoticz is using is calculating the tendency itself. As input it is using the same raw data from the API calls you now used.
So you have to calculate the tendency yourself with dzvents the same way as the highcharts module is doing.

i found the formule

n = len(days)
sum_x = sum(days)
sum_y = sum(water)
sum_xx = sum(days * days)
sum_xy = sum(days * water)

# Formules pour la pente (slope) et l'ordonnée à l'origine (intercept)
# slope = (n∑(xy)−∑x∑y)/(n∑(x^2)-∑(x)^2)
slope = (n * sum_xy - sum_x * sum_y) / (n * sum_xx - sum_x ^2)
# intercept = (∑y - slope * ∑x) /n
intercept = (sum_y - slope * sum_x) / n

tendance = slope * days + intercept

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