-----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/20220119091910.5661af6a%40wealthy.
