Hi Ian,
Following up: weewx-skyfield 1.15 is out, and the .degrees I mentioned is
in it.
$almanac.moon.parallactic_angle still returns radians, as before, for
PyEphem compatibility — but you can now override the unit by appending
.degrees:
<p>Moon parallactic angle: $("%.1f°" %
$almanac.moon.parallactic_angle.degrees)</p>
No #import math needed anymore (though the math.degrees(...) way keeps
working — the value is unchanged, still a radians float). There's also an
explicit .radians if you want to spell it out.
The same trick works on every tag that returns radians: the moon's
libration_lat/libration_long and colong, Jupiter's cmlI/cmlII, Saturn's
earth_tilt/sun_tilt, and $almanac.separation().
Release notes:
https://github.com/chaunceygardiner/weewx-skyfield/releases/tag/v1.15
Cheers,
John
On Thursday, July 30, 2026 at 5:23:30 AM UTC-7 John Kline wrote:
> Hi Ian,
>
> That one is expected: the earth is the observer in the almanac, not one of
> the bodies it serves, so there's no $almanac.earth — same as PyEphem, which
> has Sun, Moon, and Mercury through Pluto, but no Earth body.
>
> Earth's heliocentric longitude is still available, though, just under a
> different name. Since the sun's own heliocentric coordinates are undefined
> (it sits at the origin), $almanac.sun.hlongitude reports the Earth's
> heliocentric ecliptic longitude — a convention inherited from
> XEphem/PyEphem. So:
>
> $rad($almanac.sun.hlongitude.raw)
>
> completes your set of nine, computed in the same frame as the others.
>
> This is deliberate, and it's a policy: weewx-skyfield aims to be a drop-in
> replacement for WeeWX's built-in PyEphem almanac. Every tag that worked
> before keeps working and means the same thing — the test suite carries a
> permanent parity audit that evaluates everything the built-in almanac could
> do against both engines. Where we knowingly deviate (only where PyEphem is
> measurably wrong, e.g. Jupiter's central meridian longitudes), each case is
> documented in the README under "Differences from PyEphem". So when a tag
> like $almanac.earth doesn't resolve, that's fidelity to the original
> almanac rather than a gap.
>
> Regards,
> John
>
> On Jul 29, 2026, at 11:54 PM, Ian <[email protected]> wrote:
>
> Hi again John,
>
>
>
> Just one more thing
>
> All these values are resolving except for earth
>
> $rad($almanac.mercury.hlongitude.raw)
> $rad($almanac.venus.hlongitude.raw)
> $rad($almanac.earth.hlongitude.raw)
> $rad($almanac.mars.hlongitude.raw)
> $rad($almanac.jupiter.hlongitude.raw)
> $rad($almanac.saturn.hlongitude.raw)
> $rad($almanac.uranus.hlongitude.raw)
> $rad($almanac.neptune.hlongitude.raw)
> $rad($almanac.pluto.hlongitude.raw)
>
> Thanks
> Ian
>
>
> On Wednesday, July 29, 2026 at 9:13:40 PM UTC+1 Ian wrote:
>
>> Hi John,
>>
>> I don't no how many times I read through that and I missed it!
>>
>> Thanks
>> Ian
>>
>>
>> On Wednesday, July 29, 2026 at 8:28:46 PM UTC+1 John Kline wrote:
>>
>>> Hi Ian,
>>>
>>> Thanks for the kind words!
>>>
>>> Good news: it's already there.
>>>
>>> $almanac.moon.parallactic_angle works today (since 1.0), returning
>>> radians as PyEphem did.
>>>
>>> For degrees:
>>>
>>> #import math
>>> $("%.1f°" % math.degrees($almanac.moon.parallactic_angle))
>>>
>>> Example:
>>>
>>> #import math
>>> ...
>>> <p>Moon parallactic angle: $("%.1f°" %
>>> math.degrees($almanac.moon.parallactic_angle))</p>
>>>
>>> It works for any body, not just the moon.
>>>
>>> Note: I could make $almanac.moon.parallactic_angle.degrees work (rather
>>> than having to concrete it). I return radians for PyEphem compatability;
>>> but I could keep that and still support the .degrees. I’ll probably do that
>>> in the next release.
>>>
>>> Cheers,
>>> John
>>> > On Jul 29, 2026, at 12:06 PM, Ian <[email protected]> wrote:
>>> >
>>> > John,
>>> >
>>> > This is really tremendous stuff. I wondered is there any chance that
>>> you could add a tag for moon's parallactic angle.
>>> > Crongratulations and thank you
>>> >
>>> > Ian
>>>
>> --
>
> You received this message because you are subscribed to the Google Groups
> "weewx-user" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to [email protected].
>
> To view this discussion visit
> https://groups.google.com/d/msgid/weewx-user/96983ce1-6398-447d-9f19-1aeeae74faf3n%40googlegroups.com
>
> <https://groups.google.com/d/msgid/weewx-user/96983ce1-6398-447d-9f19-1aeeae74faf3n%40googlegroups.com?utm_medium=email&utm_source=footer>
> .
>
>
--
You received this message because you are subscribed to the Google Groups
"weewx-user" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To view this discussion visit
https://groups.google.com/d/msgid/weewx-user/4c9254cf-005f-4895-97ea-c009f2da6130n%40googlegroups.com.
