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XType extension for WeeWX to provide
- "Grünlandtemperatursumme" (a kind of growing degree days)
- observation types 'dayET' and 'ET24' as the opposite to 'dayRain' and 'rain24'
- observation types for equivalent (potential) temperature, mixing ratio, absolute humidity, and (saturation) vapor power
- additional aggregation type for 'radiation' to calculate the total energy received during the aggregation interval
- tags for day boundaries other than midnight local timezone time
- observation types 'yearGDD' and 'seasonGDD'
- aggregation type 'GDD'
If you want to report bugs or need help, please, refer to Help! Posting to weewx user for instructions. It applies here, too.
Please note, that GTS and yearGDD require temperature data from
January 1st on to be calculated. If your database does not cover the
whole timespan, those values cannot be calculated. You will have to
wait for the next year.
If skin creation lasts too long for you, please, read the WeeWX wiki article XTypes performance first before creating an issue here. We can try to optimize things, but we cannot do magic.
-
download
wget -O weewx-GTS.zip https://github.com/roe-dl/weewx-GTS/archive/master.zip
-
run the installer
WeeWX up to version 4.X
sudo wee_extension --install weewx-GTS.zip
WeeWX from version 5.0 on and WeeWX packet installation
sudo weectl extension install weewx-GTS.zip
WeeWX from version 5.0 on and WeeWX pip installation into an virtual environment
source ~/weewx-venv/bin/activate weectl extension install weewx-GTS.zip
-
check configuration in weewx.conf
[StdWXCalculate] [[Calculations]] ... GTS = software,archive GTSdate = software, archive utcoffsetLMT = software, archive dayET = prefer_hardware, archive ET24 = prefer_hardware, archive yearGDD = software, archive seasonGDD = software, archive outVaporP = software,loop outSVP = software,loop outMixingRatio = software,loop outEquiTemp = software,loop outThetaE = software,loop outHumAbs = software,loop ... [Engine] [[Services]] ... xtype_services = ... ,user.GTS.GTSService -
restart weewx
for SysVinit systems:
sudo /etc/init.d/weewx stop sudo /etc/init.d/weewx start
for systemd systems:
sudo systemctl stop weewx sudo systemctl start weewx
You can use the values provided by this extensions in all skins of WeeWX. You can show the values, and you can create a diagram. The following observation types are provided:
"Grünlandtemperatursumme" is a kind of growing degree days that is used to estimate the start of growing of the plants. For the algorithm see below.
GTS: the value of "Grünlandtemperatursumme" itself (example tag:$current.GTS)GTSdate: the date when the GTS value exceeds 200, which is considered the beginning of real spring (example tag:$day.GTSdate.last.format("%Y-%m-%d"))utcoffsetLMT: offfset of the local mean time (Ortszeit) at the station's locationLMTtime: a string showing the local mean time (Ortszeit) at the station's location (can only be used with ".raw", example tag:$current.LMTtime.raw)
The values can be used together with every time period defined in the customization guide of WeeWX. There can be used aggregations as well. The following aggregations are defined:
avg, min, max, last, has_data, not_null. Not all time spans are possible.
See http://weewx.com/docs/customizing.htm#Tags for details on how to use tags in skins.
Caution: The aggregation exists only reports whether the observation
type is included in the database or not. For pure XTypes like the observation
types provided here it reports False. The behavior of has_data changed.
It reports False for WeeWX up to version 4.10 and True for WeeWX from
version 5.0 on.
To create diagrams you need to include additional sections into the [ImageGenerator] section of skin.conf. What follows are examples. There are more possibilities than that.
Within [[month_images]]:
[[[monthGTS]]]
line_gap_fraction = 0.04
yscale = 0,None,None
aggregate_type = avg
[[[[GTS]]]]
aggregate_interval = 86400
label = Grünlandtemperatursumme
Within [[year_images]]:
[[[yearGTS]]]
aggregate_type = avg
[[[[GTS]]]]
label = Grünlandtemperatursumme
These examples create image files named 'monthGTS.png' or 'yearGTS.png', respectively. To display them within the web page appropriate <img> tags need to be included for example in index.html.tmpl:
<img src="monthGTS.png" />
<img src="yearGTS.png" />
see Using weewx-GTS in WDC wiki
configuration in graphs.conf:
[[Vegetation]]
#title = "Grünlandtemperatursumme"
title = "Vegetation"
aggregate_type = avg
yAxis_label = "Wachstumsgradtage"
yAxis_softMin = 100
yAxis_softMax = 200
exporting = 1
[[[GTS]]]
observation_type = GTS
name = "Grünlandtemperatursumme"
[[[yearGDD]]]
observation_type = yearGDD
name = "Wachstumsgradtage"
[[[seasonGDD]]]
observation_type = seasonGDD
name = "Wachstumsgradtage Saison"
yearGDD: the sum or integral of growing degrees from the beginning of the actual year up to the current timeseasonGDD: the sum or integral of growing degrees fromGTSdateup to the current time. BeforeGTSdatethe value is undefined. After October 31st it is undefined, too.- aggregation type
GDD(orgrowdeg): Used to calculate growing degree days for observation types other thanoutTemp. This can be every temperature value, say greenhouse temperature.
Within [[year_images]]:
[[[yearGDD]]]
aggregate_type = avg
[[[[yearGDD]]]]
label = Growing degree days
[[[[seasonGDD]]]]
label = Season growing degree days
This example creates an image files named 'yearGDD.png'. To display it within the web page appropriate <img> tags need to be included for example in index.html.tmpl:
<img src="yearGDD.png" />
You can combine that with GTS:
[[[yearGTS]]]
aggregate_type = avg
[[[[GTS]]]]
label = Grünlandtemperatursumme
[[[[yearGDD]]]]
label = Growing degree days
[[[[seasonGDD]]]]
label = Season growing degree days
To display it within the web page include the appropriate <img> tag for example into index.html.tmpl:
<img src="yearGTS.png" />
see Using weewx-GTS in WDC wiki
see above
dayET: the sum of ET from the beginning of the archive day on, like dayRain does for rainET24: the sum of ET over the last 24 hours, like rain24 does for rain
dayET and ET24 are not used in plots.
WeeWX already includes the calculation of some special derived
meteorological readings, but they are used internally, only. This
extension makes them available for use in section [StdWXCalculate]
and in tags.
Please note: WeeWX comes with an example extension, that calculates a value called "vapor pressure", but it is in fact saturation vapor pressure. The example uses another algorithm than WeeWX internally.
Caution: The calculation of these values is alpha code. It needs to be evaluated.
outSVP: saturation vapor pressureoutVaporP: actual vapor pressureoutMixingRatio: mixing ratiooutHumAbs: absolute humidityoutEquiTemp: equivalent temperatureoutThetaE: equivalent potential temperatureboilingTemp: boiling temperature depending on station altitude and actual air pressure
To show diagrams of these readings there is no need to store them in database. They will be calculated "on the fly" by the XTYPE system of WeeWX.
Example: absolute humidity
[[[dayhumabs]]]
unit = gram_per_meter_cubed
[[[[outHumAbs]]]]
Example: Display both the relative and absolute humidity in one diagram
[[humidity]]
title = "Humidity"
[[[outHumidity]]]
name = "relative
[[[outHumAbs]]]
name = "absolute"
yAxis = 1
unit = gram_per_meter_cubed
[[[[numberFormat]]]]
decimals = 1
'radiation' and 'maxSolarRad' are built-in observation types of WeeWX. This extension only provides an additional aggregation type to them. It is called 'energy_integral' and calculates the total energy received during the aggregation interval.
Note: An Integral is not a sum of observation readings. See below for algorithm.
You need to use this aggregation type together with aggregation timespans
like $day, $yesterday, $week, $month, and $year as well as
timespans defined by some other extension to WeeWX.
energy_integral can be used like any other aggregation type like min,
max, or sum.
Example:
$yesterday.radiation.energy_integral displays the total sun energy
received the day before.
To display the value in kWh/m^2 instead of Wh/m^2 use:
$yesterday.radiation.energy_integral.kilowatt_hour_per_meter_squared
Within [[month_images]]:
[[[monthRadiationEnergy]]]
line_gap_fraction = 0.04
#y_label = "Wh/m²"
[[[[radiation]]]]
label = "Sonnenenergie (täglich gesamt)"
data_type = radiation
aggregate_type = energy_integral
aggregate_interval = 86400
This example creates an image file called 'monthRadiationEnergy.png' To display it within the web page an appropriate <img> tag needs to be included for example in index.html.tmpl:
<img src="monthRadiationEnergy.png" />
Belchertown skin uses another plot engine (Highcharts). Therefore the syntax is slightly different.
In section [month] or [year] of graphs.conf:
[[Sonnenenergie]]
title = "Sonnenenergie (täglich gesamt)"
aggregate_type = energy_integral
aggregate_interval = 86400
yAxis_label = Energie
yAxis_label_unit = "Wh/m²"
[[[radiation]]]
No <img> tag is needed.
There is an example template to create a text file showing monthly
summeries of sun energy and sun radiation in the examples directory.
To use it, copy the file to your skin directory and add the following
to your skin.conf:
[CheetahGenerator]
...
[[SummaryByYear]]
...
[[[sun_year]]]
encoding = strict_ascii
template = sun-%Y.txt.tmpl
This creates a file for every year that data is available for.
For soil moisture WeeWX defines the unit group group_moisture
using the unit centibar. This presumably refers to the Davis
Instruments soil moisture/temperature station 6345, which
strictly speaking does not measure moisture but suction pressure.
Sometimes this pressure is expressed in a logarithmic value
called pF value. This extension provides the pF value as an
additional unit to group_moisture, called pF_value.
It makes other pressure units than centibar available to
group_moisture, too.
Sometimes day span used in meteorology are not from midnight to midnight
but start and end at some arbitrary time of day like 09:00 a.m. To
aggregate values with day boundaries other than midnight the following
tags are provided. They are used like standard $hour, $day etc.
$offsethour(data_binding=None, hours_ago=0, dayboundary=None)$offsetday(data_binding=None, days_ago=0, dayboundary=None)$offsetyesterday(data_binding=None, dayboundary=None)$offsetmonth(data_binding=None, months_ago=0, dayboundary=None)$offsetyear(data_binding=None, years_ago=0, dayboundary=None)
dayboundary is an offset to UTC in seconds, that sets the time of day
to use as the day boundary for the given aggregation. In case of Python
<3.7 the value is rounded to whole minutes.
$LMThour(data_binding=None, hours_ago=0)$LMTday(data_binding=None, days_ago=0)$LMTyesterday(data_binding=None)$LMTmonth(data_binding=None, months_ago=0)$LMTyear(data_binding=None, years_ago=0, month_span=None)
Day boundary is midnight Local Mean Time which is always near the antitransit of the sun at the station's location.
The optional parameter month_span is a time span of several months
within the given year. For example $LMTyear(month_span=(6,8)).outTemp.avg
is the average temperature of the summer of the actual year.
$LMTyear(years_ago=1,month_span=(12,2)).outTemp.max is the
maximum temparature of the last winter season.
The attribute days can be used together with $LMTmonth and $LMTyear
for iteration.
-
$daylight(timestamp=None, data_binding=None, days_ago=0, horizon=None, use_center=False)timespan from sunrise to sunset
If
timestampis None (the default), it is the timespan from sunrise to sunset of the current day or the daydays_agodays ago.Otherwise
timestampcan be a class TimespanBinder, a timespan or a timestamp.$daylightis then the timespan between sunrise and sunset of the day the specified timespan or timestamp is in. This is useful in#forloops over days. -
$LMTweek(data_binding=None, months_ago=0).daylights(horizon=None, use_center=False)series of timespans describing the timespan from sunrise to sunset for each individual day. For use in
#forloops -
$LMTmonth(data_binding=None, months_ago=0).daylights(horizon=None, use_center=False)series of timespans describing the timespan from sunrise to sunset for each individual day. For use in
#forloops -
$LMTyear(data_binding=None, months_ago=0).daylights(horizon=None, use_center=False)series of timespans describing the timespan from sunrise to sunset for each individual day. For use in
#forloops
For the options horizon and use_center see
WeeWX customization guide.
If omitted, defaults are used.
Examples:
- average temperature while the sun is up
$daylight.outTemp.avg - table with day of month and the average temperature while the sun
is up on that day
#for $span in $LMTmonth.daylights <p>$span.dateTime.format("%d"): $span.outTemp.avg</p> #end for - rain during day and night of the days of the current week
#from weewx.units import ValueTuple, ValueHelper <table> <tr> <th>Day</th> <th>Day rain</th> <th>Night rain</th> </tr> #for $dd in $week.days #set $light=$daylight(timestamp=$dd) #set $nightrain=$dd.rain.sum.raw-$light.rain.sum.raw #set $nightrain_vh=ValueHelper(ValueTuple($nightrain,$unit.unit_type.rain,'group_rain'),formatter=$station.formatter) <tr> <td>$dd.start.format("%Y-%m-%d")</td> <td>$light.rain.sum</td> <td>$nightrain_vh</td> </tr> #end for </table> - sunrise, sunset, and duration of daylight using the
timestampoption<table> <tr> <th>sunrise</th> <th>sunset</th> <th>daylight</th> </tr> #for $dd in $week.days <tr> <td>$dd.format("%A")</td> <td>$daylight(timestamp=$dd).start</td> <td>$daylight(timestamp=$dd).end</td> <td>$daylight(timestamp=$dd).length</td> </tr> #end for </table>
- GTS is calculated from the daily average temperatures. If the daily average temperature is above 0°C (32°F) it is used to add to the sum, otherwise it is discarded.
- In January the daily average temperatures are multiplied by 0.5.
- In February the daily average temperatures are multiplied by 0.75.
- From March on the daily average temperatures are used as is.
- To get the GTS value of a day all the values as described above are added from January 1st to the day in question. So the GTS value increases in time.
- If the GTS value exceeds 200 this event is considered the beginning of growing of the plants in spring.
- The GTS value itself is calculated up to May 31st. The end value is considered a statement about the spring.
Radiation energy is calculated as follows: All the radiation readings within the aggregation interval are multiplied by their respective archive interval. That is based on the assumption that the radiation was constant during that interval. The error resulting form that is considered small enough to tolerate.
After that all the products of radiation and time interval are summarized together.
While the unit label of the radiation reading is W/m^2, the unit label of the radiation energy is Wh/m^2.
The $daylight tag uses the built-in module of WeeWX that provides
the $almanac tag.
While $almanac.sunrise and $almanac.sunset calculate sunrise and
sunset using the actual temperature and barometer of the calculation
time, $daylight observes temperature and barometer of the time,
the daylight timespan is calculated for if there are database records
available. It first calculates approximate sunrise and sunset times
for the ICAO standard atmosphere at 15°C and 1013.25 mbar. Then it
looks up the real temperature and barometer for both those times.
After that it calculates sunrise and sunset again, using the
respective temperature and barometer.
That's why $daylight(timestamp=$X).start provides a more accurate
time for sunrise than $almanac(timestamp=$X).sunrise if $X
is a timestamp somewhere in the past and database records are
available for that time. The same applies to $daylight(timestamp=$X).end
instead of $almanac(almanac_time=$X).sunset for sunset and
$daylight(timestamp=$X).length instead of
$almanac(almanac_time=$X).sun.visible for the daylight duration.
WeeWX includes several algorithms to calculate the barometer value
out of the station pressure. Unfortunately those algorithms are
not available to the user by default. And by 2023 there is no
way to pass parameters to an XType. The barometer extension does
a little bit of that and allows to add an algorithm name to
the observation type barometer. This allows the following
observation types:
barometerManBarbarometerDavisVpbarometerUniviebarometerDWD
This is a temporary workaround only. It will be removed when WeeWX fully implements parameters to observation types.
- http://www.groitzsch-wetter.de/HP/green1.html
- http://www.regionalwetter-sa.de/sa_gruenland.php
- WeeWX examples/stats.py
- WeeWX homepage - WeeWX Wiki
- Belchertown skin homepage - Belchertown skin Wiki
- Wöllsdorf weather conditions
- XTypes performance (Read this article in case your skin creation lasts too long.)