To be sure, it is an expensive calculation because the whole database would have to be searched. The daily summaries cannot be used because they are aggregates over a day.
Precalculating would speed things up. -tk On Sat, Oct 23, 2021 at 6:25 AM p q <[email protected]> wrote: > Maybe it would be better to precompute the one hour (good enough? Or one > minute?) historical averages and store it in the database rather than > calculate it on the fly. > > On Sat, Oct 23, 2021, 5:35 AM Tom Keffer <[email protected]> wrote: > >> If I understand you correctly, you want to graph the day's temperature, >> along with the average historical temperature for the same time of day. >> >> The extension that Peter is referring to is the XAggs extension >> <https://github.com/tkeffer/weewx-xaggs>, but it does something slightly >> different. It calculates historical data (high, low, average, etc.) for the >> *whole >> day*, not just a particular time. It does this by offering new >> aggregation types, such as historical_avg, so you can request something >> like *$day.outTemp.historical_avg* and get the average temperature for >> today. That's not quite what you want, because you want the average for a >> particular time. >> >> Not sure how to handle that. Perhaps by defining a new type, call it >> outTemp_avg? Think of it as a new column in the database. although the >> XTypes <https://github.com/weewx/weewx/wiki/WeeWX-V4-user-defined-types> >> system allows you to define new types virtually, so you don't have to >> actually put it in the database. Then it could be specified like any other >> type: >> >> [[day_images]] >> ... >> [[[dayhistorical]]] >> [[[[outTemp]]]] >> [[[[outTemp_avg]]]] >> >> I think you can get away with just defining the XTypes function >> get_scalar(). Schematically, this would look something like this: >> >> class HistoricalAvg(weewx.xtypes.XType): >> def get_scalar(self, obs_type, record, db_manage): >> if obs_type != 'outTemp_avg': >> raise weewx.UnknownType(obs_type) >> ... Get the time of day for this record ... >> ... Look through the database for the average temperature for >> that time ... >> ... return it as a ValueTuple... >> >> As you can see, I've left out a lot of details! Read through the XTypes >> documentation >> <https://github.com/weewx/weewx/wiki/WeeWX-V4-user-defined-types> and >> see if you want to tackle this project. >> >> -tk >> >> On Sat, Oct 23, 2021 at 3:38 AM [email protected] <[email protected]> >> wrote: >> >>> What is that extension? >>> What I want is a graph that has the current temperature and the average >>> temperature that corresponds to all the records in the database with the >>> same day and time. >>> >>> El viernes, 22 de octubre de 2021 a las 15:58:20 UTC+2, >>> [email protected] escribió: >>> >>>> Someone wrote a search extension for "on this date" that would allow >>>> you to pull up the stats for a given date over time. I use it to show the >>>> high/low/rain for today's date for the years that I have data. Search this >>>> forum for it, if that's what you're looking for. >>>> >>>> On This Day >>>> Oct 22 2016 >>>> H: 83.8°F L: 51.0°F >>>> 2017 >>>> H: 77.2°F L: 47.6°F >>>> 2018 >>>> H: 76.9°F L: 49.4°F >>>> 2019 >>>> H: 86.2°F L: 49.8°F >>>> 2020 >>>> H: 82.6°F L: 52.4°F >>>> >>>> On Fri, Oct 22, 2021 at 6:27 AM [email protected] <[email protected]> >>>> wrote: >>>> >>>>> Would it be possible to make a graph with the historical temperature >>>>> of that same day at that same time with all the data in the database? >>>>> And another would be the temperature anomaly with the current moment. >>>>> Thank you. >>>>> >>>>> -- >>>>> 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 on the web visit >>>>> https://groups.google.com/d/msgid/weewx-user/61df7337-1936-43eb-b4e0-46ffaae5a6c1n%40googlegroups.com >>>>> <https://groups.google.com/d/msgid/weewx-user/61df7337-1936-43eb-b4e0-46ffaae5a6c1n%40googlegroups.com?utm_medium=email&utm_source=footer> >>>>> . >>>>> >>>> >>>> >>>> -- >>>> Peter Quinn >>>> (415)794-2264 <(415)%20794-2264> >>>> >>> -- >>> 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 on the web visit >>> https://groups.google.com/d/msgid/weewx-user/08e13c07-0811-4abe-a12d-4ff54f593211n%40googlegroups.com >>> <https://groups.google.com/d/msgid/weewx-user/08e13c07-0811-4abe-a12d-4ff54f593211n%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 on the web visit >> https://groups.google.com/d/msgid/weewx-user/CAPq0zEBJ2dgEWwKbyj70aFXZ9-FLD%3Du%2BrY51%2BY6dS-b9oHF4aw%40mail.gmail.com >> <https://groups.google.com/d/msgid/weewx-user/CAPq0zEBJ2dgEWwKbyj70aFXZ9-FLD%3Du%2BrY51%2BY6dS-b9oHF4aw%40mail.gmail.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 on the web visit > https://groups.google.com/d/msgid/weewx-user/CAA1SM23F_HuUvKN62S61sdx-nEFFMBXKV9nTGYDNbHWg6VTUvA%40mail.gmail.com > <https://groups.google.com/d/msgid/weewx-user/CAA1SM23F_HuUvKN62S61sdx-nEFFMBXKV9nTGYDNbHWg6VTUvA%40mail.gmail.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 on the web visit https://groups.google.com/d/msgid/weewx-user/CAPq0zEAsaQb4G591DJ1ShLt1MD8kh4JPqwTknm9y2Y8S%2BHSzug%40mail.gmail.com.
