Your Phenology extension is actually what got me thinking about how to implement the chilling hours in a more generic way, such that more than one metric (or one set of temperature thresholds) can be used.
The "simplest" way that came to mind was using some sort of modified Daily Summary table in the database. I haven't yet figured out how WeeWX populates those tables, but if the columns and calculation methods are customizable, then the daily (or nightly) data could be compiled at the end of the day and loaded into the table. That way every time you want to display the information, it's just a straight query from that summary table, rather than running the calculations every time for every archive entry. This also allows for multiple calculation methods, all stored in the summary table. So as an example, at the end of the day, whenever WeeWX normally populates the summary tables, this new extension could run multiple algorithms (one for basic chill hours, one for the Utah Model, one for the phenology table on your website, etc) and store the resultant value in the respective column (one for Utah, one for basic, one for phenology, etc) in the new daily summary row for this extension. No new specific types are required in the loop or archive packets, so the processing power is only required once per day. When the data is viewed, it is only pulling values from a table rather than doing the calculations each time. But I'm not sure such customizations to the daily-table-creation-process is possible. Thoughts? On Wednesday, January 19, 2022 at 9:20:30 AM UTC-6 [email protected] wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > On Tue, 18 Jan 2022 17:05:33 -0800 > Tom Deffer <[email protected]> wrote: > > > Upon reflection, the biggest difference seems to be that > > cooling-degree days are weighted by the temperature difference from > > the baseline. You just want the total number of hours. > > > This is best done as an XTypes extension > > <HTTP://git hub.com/weewx/weewx/wiki/WeeWX-V4-user-defined-types>. > > I've fooled around with XTypes for my Phenology extension. > > * [weewx-phenology](HTTP://LacusVeris.com/Phenology) — Growing > Degree-Days development models for various insect pests, showing > when to apply control strategies to minimize crop damage. > > The Growing Degree-Days calculation(s) are compute-intensive relative > to the Cooling Degree-Days calculation. XTypes exposes three entry > points that return values: scalar, series, and aggregate. I implement > only the "series" entry point, and I keep a running tally of > cumulative Degree-Days. It seems that, if I had implemented > "aggregate," each cumulative step would have meant recalculating > previous steps at factorial cost, but that's just me. > > I agree the Chilling Hours calculations seem relatively simple, but > never let it be said that researchers in the Life Sciences can leave > any particularly elegant concept uncluttered. Here is a more or less > grammatical overview of various kinds of Chilling Hours calculations. > You may overlook the Climate Change hysteria at the end. The Utah > method obviously requires quite a few machine cycles, but matching the > Queensland method's curve might require quite a few more. > > * [Chill Hours and Fruit > Trees](https://practicalprimate.com/chill-hours/) — Many deciduous > fruit trees will not give you the fruit yields you want unless your > property receives adequate chill hours. But what are chill hours and > why are they so important? > > ... so both Chill Hours and Growing Degree-Days potentially challenge > WeeWX's data collection, calculation, reporting, and image generation > capabilities. I developed a kludge to handle Growing Degree-Days > because treating orchard insects and disease is a season-to-season > battle and many treatments depend on such calculations. I am not so > interested in Chill Hours because that has more to do with orchard > siting and choice of cultivars, which tend to be one-off decisions. > However, Chill Hours (in whatever manifestation) does keep coming up > here and on the other discussion group I frequent. Perhaps this is > due to ongoing Climate-Change concerns. > > * [Growing Fruit](https://growingfruit.org/search?q=chill%20hours) > > I wonder whether I have gone down the right chute with the Phenology > Extension's Growing Degree-Days calculation and imaging capacity. > Does adding Chill Hours call for a more general approach? > > I sadly fear the appetite for reporting Chill Hours does not > necessarily imply the desire or ability to configure WeeWX to do the > appropriate calculations or interpret the results. These are not > straightforward things. > > - -- > .. Be Seeing You, > .. Chuck Rhode, Sheboygan, WI, USA > .. Weather: http://LacusVeris.com/WX > .. 15° — Wind WNW 22 mph — Sky mostly clear. > > -----BEGIN PGP SIGNATURE----- > > iF0EARECAB0WIQT+MY/5I/LMPSswTbVg2/xipKOWUgUCYegsMQAKCRBg2/xipKOW > UuoSAJ4kvvWrCWqDkEZ8tl2yDzAPXU3LnQCeO5z01CamBSnFAr677iJNzwgf15U= > =aptL > -----END PGP SIGNATURE----- > -- 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/07e91ec6-4eca-4023-8bc0-691b5e8679ffn%40googlegroups.com.
