- Platform information:
- Hardware: Raspberry Pi 4
- OS: Newest OpenHabian, default installation
- openHAB version: 3.3

I’m trying to write a rule that will forecast solar radiation on an arbitrary day of the year. Eventually, the goal is to use this to control the charging behavior of a battery/PV system when combined with weather forecasting data.

Unfortunately, I seem to have written a rule that can’t be compiled? With the rule in place, OpenHab just gets completely stuck during startup and never moves past `[el.core.internal.ModelRepositoryImpl] - Loading model 'SMART_SolCasting.rules'`

. It doesn’t even say there was a compiliation error or anything, it simply sits there.

Checking `top`

reveals that even minutes after starting, the java process consumes ~130% of CPU.

So, my question: Did I do something “illegal”? Did I goof the syntax somewhere or is there too much trigonometry for java to handle? It’s very frustrating to test what exactly is causing the issue, because whatever it is, it doesn’t get cleared away by a `systemctl restart openhab`

but rather requires a full reboot before the rules engine starts working again.

Here my code:

```
import java.util.List
import java.util.ArrayList
//Forecasting of solar stuff
rule "rule name"
when
Item triggerDebug received command ON
then
logInfo("SolCasting", "Beginning Calculation...")
//Get the current Decimal Local time
//var v_LT = now.getHour + now.getMinute * 0.01666666
//Get the current day of the year
var v_D = now.getDayOfYear
//var v_D = 365
val Lat = 50.0
val Lon = 9
val unused = 0
var pi180 = 0.0174532925
//Do Timezone nonsense
val v_dUTC = Integer.parseInt( now.getOffset.toString.substring(1,3) )
val v_LTSM = 15.0 * v_dUTC
//Calculate EoT for the day
var v_B = ( (360.0 / 365.0) * (v_D - 81) ) * pi180
var v_EoT = 9.87 * Math::sin( 2 * v_B ) - 7.53 * Math::cos( v_B ) - 1.5 * Math::sin( v_B )
//Find Time correction (in minutes)
val v_TC = 4 * (Lon - v_LTSM) + v_EoT
//Calculate High noon
val v_LST_noon = 12 - v_TC / 60
//Calculate the day's Declination
val v_decl = ( 23.45 * pi180 * Math::sin( v_B ) ) * 57.2958
//Calculate the Solar Zenith/Elevation Angles
var List<Float> v_elevation = newArrayList(0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23)
for(var c = 0; c < 24; c = c + 1){
v_elevation.add(c, Math::asin( Math::sin( v_decl * pi180) * Math::sin( Lat * pi180 ) + Math::cos( v_decl * pi180) * Math::sin( Lat * pi180 ) * Math::cos( pi180 * (15 * ((c + v_TC / 60) - 12)) ) ) )
}
for(var c = 0; c < 24; c = c + 1){
logInfo("SolCasting", "Hour " + c + " Solar Elevation " + v_elevation.get(c))
}
logInfo("SolCasting", "Current day " + v_D )
logInfo("SolCasting", "Current v_B " + v_B )
logInfo("SolCasting", "Current EoT " + v_EoT )
logInfo("SolCasting", "Todays time correction: " + v_TC)
logInfo("SolCasting", "High Noon Today: " + v_LST_noon)
logInfo("SolCasting", "Today's Solar Declination: " + v_decl)
end
```

Also, more generally, is there a better way to do this (forecast solar stuff)? The Astro binding delivers current radiation values, but afaik can’t predict future ones which is inconvenient.