OK. What I don't understand is that my code had always a test if hauteur_soleil > 3: (according to Météo France)
or more recently if hauteur_soleil > 0: in the function, and this test is not on your function. It should be : hauteur_soleil = asin(sin((pi / 180) * latitude) * sin((pi / 180) * declinaison) + cos( (pi / 180) * latitude) * cos((pi / 180) * declinaison) * cos((pi / 180) * angle_horaire)) * (180 / pi) If hauteur_soleil > 0: seuil = (0.73 + 0.06 * cos((pi / 180) * 360 * dayofyear / 365)) * 1080 * pow( (sin(pi / 180) * hauteur_soleil), 1.25) * coeff else : seuil = 0 return seuil > Le 30 juin 2022 à 22:52, 'Peter Fletcher' via weewx-user > <weewx-user@googlegroups.com> a écrit : > > That was going to be my next step! In fact, iterating through a list of the > dateTime values that produce the errors in the real code and passing each > value to the function confirms that it is the specific dateTime values that > are causing the function to misbehave. The returned results are all complex > numbers with negative and numerically identical (for a given dateTime) real > and imaginary components. It does seem to be a bug in the function. I assume > that hauteur_soleil should always be >=0. It appears that, for my latitude > and longitude and for the given specific values of dateTime, it becomes > negative. The last step in the calculation then involves raising a negative > number to a non-integral power, which is guaranteed to produce interesting > results! The really odd thing is that math.pow is not returning a ValueError, > which the docs say is what should happen under these circumstances, but > apparently trying to return a (possibly) valid complex result. > On Thursday, June 30, 2022 at 3:07:38 PM UTC-4 jterr...@gmail.com wrote: > The only clue I have is that the problem is not due to an « overloading » of > your raspberry pi, but seems to occur with specific dateTime values. > You can try to run your script only with a « bad » dateTime : > > "SELECT dateTime, Radiation from archive where dateTime = 1592614500 » > > Does the error occurs ? If yes, you can try to add debugging print commands > inside the sunshineThreshold function to try to understand. > > > > >> Le 30 juin 2022 à 19:51, 'Peter Fletcher' via weewx-user >> <weewx...@googlegroups.com >> <applewebdata://53FD5BF2-209C-4577-B6BF-532766329623>> a écrit : >> > >> It did as it seems you predicted - passed 1592614800 and stopped at >> 1632611100. You obviously have a clue as to what is going on. Please explain! >> >> On Thursday, June 30, 2022 at 8:59:48 AM UTC-4 jterr...@gmail.com >> <http://gmail.com/> wrote: >> If you exclude the first one,1592614500 , with a query like "SELECT >> dateTime, Radiation from archive where dateTime <> 1592614500", will the >> script stop at 1592614800 ( the next dateTime) or will it continue and stop >> at 1632611100 ? >> >> >>> Le 30 juin 2022 à 14:34, 'Peter Fletcher' via weewx-user >>> <weewx...@googlegroups.com <>> a écrit : >>> >> >>> 1592614500 >>> 1632611100 >>> 1632611400 >>> 1647688800 >>> >>> I can't see a pattern or any common features. >>> >>> On Thursday, June 30, 2022 at 3:55:49 AM UTC-4 jterr...@gmail.com >>> <http://gmail.com/> wrote: >>> No, I never had weewx crashes related to the sunshine calculations. >>> >>> What are the dateTime values that trigger the error ? >>> >>> >>> >>> Le mercredi 29 juin 2022 à 23:23:16 UTC+2, Peter Fletcher a écrit : >>> Have you had any odd weewx errors or crashes related to the sunshine >>> calculations? I ask because I hadn't, but I decided to try to 'backfill' my >>> database with sunshine times, based on the 5-minute radiation values, and I >>> ran into a bizarre bug. I used the code shown below (on a copy of my live >>> weewx database). As you will see, the threshold calculation code is >>> essentially identical to yours, except that it has been converted to a >>> regular function (no 'self' parameter) and my station's latitude and >>> longitude are hard coded in it. When the code is run under Python 3.9.2 on >>> my Pi, it initially runs without problems, but crashes after 8,000+ records >>> have been processed with a ValueError on the MaxThreshold vs threshold >>> comparison, reporting that it can't compare a complex with a float! If I >>> intercept and log the errors, it turns out that, for a few specific values >>> of dateTime, the function returns a complex number! Even more bizarrely, it >>> only seems to do that in the context of the running code. If I manually run >>> through all the operations from the function code at the Python command >>> line, using the value of dateTime that produces the first crash, all the >>> intermediate results and the final result are sane floats. >>> There appears to be a second issue, possibly related to my reading and >>> writing the database at relatively high frequency, which stalls the process >>> after about 18,000 records have been processed, but removing the database >>> writes allows it to run to completion without abolishing the consistent, >>> albeit infrequent, ValueErrors. >>> >>> [backfill.py] >>> import sqlite3 >>> from datetime import datetime >>> import time >>> from math import sin, cos, pi, asin >>> >>> def sunshineThreshold(mydatetime): >>> coeff = 0.9 # change to calibrate with your sensor >>> utcdate = datetime.utcfromtimestamp(mydatetime) >>> dayofyear = int(time.strftime("%j", time.gmtime(mydatetime))) >>> theta = 360 * dayofyear / 365 >>> equatemps = 0.0172 + 0.4281 * cos((pi / 180) * theta) - 7.3515 * sin( >>> (pi / 180) * theta) - 3.3495 * cos(2 * (pi / 180) * theta) - 9.3619 >>> * sin( >>> 2 * (pi / 180) * theta) >>> >>> latitude = 43.0346213 >>> longitude = -78.689362 >>> >>> corrtemps = longitude * 4 >>> declinaison = asin(0.006918 - 0.399912 * cos((pi / 180) * theta) + >>> 0.070257 * sin( >>> (pi / 180) * theta) - 0.006758 * cos(2 * (pi / 180) * theta) + >>> 0.000908 * sin( >>> 2 * (pi / 180) * theta)) * (180 / pi) >>> minutesjour = utcdate.hour * 60 + utcdate.minute >>> tempsolaire = (minutesjour + corrtemps + equatemps) / 60 >>> angle_horaire = (tempsolaire - 12) * 15 >>> hauteur_soleil = asin(sin((pi / 180) * latitude) * sin((pi / 180) * >>> declinaison) + cos( >>> (pi / 180) * latitude) * cos((pi / 180) * declinaison) * cos((pi / >>> 180) * angle_horaire)) * (180 / pi) >>> seuil = (0.73 + 0.06 * cos((pi / 180) * 360 * dayofyear / 365)) * 1080 >>> * pow( >>> (sin(pi / 180) * hauteur_soleil), 1.25) * coeff >>> return seuil >>> >>> >>> database = 'weewx.sdb' >>> >>> maxThreshold=0 >>> count=0 >>> conn=sqlite3.connect(database) >>> cur=conn.execute("SELECT dateTime, Radiation from archive") >>> for row in cur: >>> count += 1 >>> if (row[1] is not None) and (row[1] > 20): >>> threshold = sunshineThreshold(row[0]) >>> if threshold > maxThreshold: >>> maxThreshold = threshold >>> if row[1] > threshold: >>> conn.execute("UPDATE archive set SunshineTime = 5 WHERE dateTime = >>> " + str(row[0])) >>> if count % 1000 == 0: >>> print(count, 'Max Threshold', maxThreshold) >>> conn.close >>> [/backfill.py] >>> >>> On Friday, June 10, 2022 at 3:29:40 AM UTC-4 jterr...@gmail.com <> wrote: >>> On my side, I have looked at the CPU utilization on my raspberry Pi 3B+. I >>> have the mqtt service service installed, so at each loop all data of the >>> packet are sent to the mqtt broker. >>> >>> With mqtt and when calculations of the sunshine threshold is done for each >>> loop packet, the total CPU utilization of python3 is about 0.75% >>> With mqtt and without calculation of sunshine threshold : 0.5% of total CPU. >>> >>> So one can estimate that 0.25 % of total CPU is needed for the calculation >>> of the threshold value for each LOOP packet. >>> >>> >>> >>>> Le 9 juin 2022 à 22:26, 'Peter Fletcher' via weewx-user >>>> <weewx...@googlegroups.com <>> a écrit : >>>> >>> >>>> After some experimentation, I found that the radiation value in the VP2 >>>> LOOP packets does, indeed, normally change every 50-52 seconds, but, >>>> perhaps about a fifth of the 'gaps' are a multiple of that time - most >>>> often 100+ or 150+ seconds, but occasionally more than that (I saw one >>>> 250+ second 'gap'). I saw this under conditions of variable sunshine and >>>> clouds when it seemed unlikely that the actual radiation value would have >>>> been precisely constant for that length of time, so I am not sure exactly >>>> what is going on. In any event, I am revising the code I am using on the >>>> basis of doing the threshold calculation when the radiation level changes, >>>> but at least every minute, if it remains constant for more than the normal >>>> 50-52 seconds.. >>>> >>>> On Sunday, June 5, 2022 at 12:33:47 PM UTC-4 jterr...@gmail.com >>>> <http://gmail.com/> wrote: >>>> I think it is also OK to do an average for every 30 seconds. It depends >>>> also on the weather station used. >>>> For instance, a Davis Vantage Pro 2 ISS transmits an updated solar >>>> radiation value every 50 to 60 seconds. So with this weather station, even >>>> a 1 minute average would not be very different since anyway the solar >>>> radiation values of the LOOP packet are the same for at least 50 seconds.! >>>> >>>> >>>>> Le 5 juin 2022 à 18:02, 'Peter Fletcher' via weewx-user >>>>> <weewx...@googlegroups.com <>> a écrit : >>>>> >>>> >>>>> I chose to average the LOOP radiation readings and only to do the >>>>> threshold calculation and make the sun/no sun determination every 30 >>>>> seconds because I thought doing it on every LOOP might overload LOOP >>>>> processing (I am running weewx on a Pi 3B, which is also doing a few >>>>> other things which use the CPU). If this is an unnecessary concern, as it >>>>> may very well be, your modified code is much cleaner than mine. >>>>> >>>>> On Saturday, June 4, 2022 at 12:41:08 PM UTC-4 jterr...@gmail.com >>>>> <http://gmail.com/> wrote: >>>>> It is a very good idea to calculate the sunshine duration for each LOOP >>>>> packet and sum these values to make the final archive sunshine duration. >>>>> I have modified my script accordingly : >>>>> https://github.com/Jterrettaz/sunduration >>>>> <https://github.com/Jterrettaz/sunduration>. >>>>> The logic is the following : for each received LOOP packet, the >>>>> radiation is compared to a calculated threshold. If the radiation is >>>>> above the threshold value, the sunshine time for the LOOP packet is equal >>>>> to the time elapsed between the previous loop packet and this packet >>>>> (most of the time 2 seconds with a Vantage Davis Pro). >>>>> The final archive sunshine duration is the sum of all the LOOP value >>>>> within the archive period. >>>>> Le vendredi 3 juin 2022 à 21:59:36 UTC+2, Peter Fletcher a écrit : >>>>> That makes some sense when you are getting data from an 'external' >>>>> sensor, though there are (IMHO) simpler ways of doing it. weewx already >>>>> has access to the LOOP radiation data from the VP2, so handling the >>>>> processing and data storage within weewx makes more sense to me in this >>>>> case. >>>>> >>>>> On Friday, June 3, 2022 at 3:24:23 PM UTC-4 vince wrote: >>>>> On Friday, June 3, 2022 at 11:17:00 AM UTC-7 Meteo Oberwallis wrote: >>>>> if the interval of Weewx and the data logger is set to 10 minutes, I >>>>> would have liked to read the value of the solar sensor every minute and >>>>> then write it into a separate .sdb database as possible sunshine. >>>>> >>>>> Personally I'd use an external program called via cron and posting a >>>>> message to a MQTT topic. Have weewx subscribe to that topic to get the >>>>> data into your db. >>>>> >>>>> This is how I used to get my DS18b20 temperature sensor data into weewx. >>>>> >>>>> >>>> >>>>> -- >>>>> You received this message because you are subscribed to a topic in the >>>>> Google Groups "weewx-user" group. >>>>> To unsubscribe from this topic, visit >>>>> https://groups.google.com/d/topic/weewx-user/19ylVTRqbh4/unsubscribe >>>>> <https://groups.google.com/d/topic/weewx-user/19ylVTRqbh4/unsubscribe>. >>>>> To unsubscribe from this group and all its topics, send an email to >>>>> weewx-user+...@googlegroups.com <>. >>>>> To view this discussion on the web visit >>>>> https://groups.google.com/d/msgid/weewx-user/0e631671-0a74-4963-9f1c-e5f81bc7c366n%40googlegroups.com >>>>> >>>>> <https://groups.google.com/d/msgid/weewx-user/0e631671-0a74-4963-9f1c-e5f81bc7c366n%40googlegroups.com?utm_medium=email&utm_source=footer>. >>>> >>>> >>>> -- >>>> You received this message because you are subscribed to a topic in the >>>> Google Groups "weewx-user" group. >>>> To unsubscribe from this topic, visit >>>> https://groups.google.com/d/topic/weewx-user/19ylVTRqbh4/unsubscribe >>>> <https://groups.google.com/d/topic/weewx-user/19ylVTRqbh4/unsubscribe>. >>>> To unsubscribe from this group and all its topics, send an email to >>>> weewx-user+...@googlegroups.com <>. >>> >>>> To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/weewx-user/f0ecc86f-a615-4a24-a43f-ee0d3963b8adn%40googlegroups.com >>>> >>>> <https://groups.google.com/d/msgid/weewx-user/f0ecc86f-a615-4a24-a43f-ee0d3963b8adn%40googlegroups.com?utm_medium=email&utm_source=footer>. >>> >>> >>> -- >>> You received this message because you are subscribed to a topic in the >>> Google Groups "weewx-user" group. >>> To unsubscribe from this topic, visit >>> https://groups.google.com/d/topic/weewx-user/19ylVTRqbh4/unsubscribe >>> <https://groups.google.com/d/topic/weewx-user/19ylVTRqbh4/unsubscribe>. >>> To unsubscribe from this group and all its topics, send an email to >>> weewx-user+...@googlegroups.com <>. >> >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/weewx-user/39cf6daa-80ca-4ffb-89d3-0f00b971481an%40googlegroups.com >>> >>> <https://groups.google.com/d/msgid/weewx-user/39cf6daa-80ca-4ffb-89d3-0f00b971481an%40googlegroups.com?utm_medium=email&utm_source=footer>. >> >> >> -- >> You received this message because you are subscribed to a topic in the >> Google Groups "weewx-user" group. >> To unsubscribe from this topic, visit >> https://groups.google.com/d/topic/weewx-user/19ylVTRqbh4/unsubscribe >> <https://groups.google.com/d/topic/weewx-user/19ylVTRqbh4/unsubscribe>. >> To unsubscribe from this group and all its topics, send an email to >> weewx-user+...@googlegroups.com >> <applewebdata://53FD5BF2-209C-4577-B6BF-532766329623>. > >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/weewx-user/c07ed2bb-1e3d-43e2-b08c-08a7a3aa92dbn%40googlegroups.com >> >> <https://groups.google.com/d/msgid/weewx-user/c07ed2bb-1e3d-43e2-b08c-08a7a3aa92dbn%40googlegroups.com?utm_medium=email&utm_source=footer>. > > > -- > You received this message because you are subscribed to a topic in the Google > Groups "weewx-user" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/weewx-user/19ylVTRqbh4/unsubscribe > <https://groups.google.com/d/topic/weewx-user/19ylVTRqbh4/unsubscribe>. > To unsubscribe from this group and all its topics, send an email to > weewx-user+unsubscr...@googlegroups.com > <mailto:weewx-user+unsubscr...@googlegroups.com>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/weewx-user/f287c1b3-1005-409c-82a9-a072e375d5e9n%40googlegroups.com > > <https://groups.google.com/d/msgid/weewx-user/f287c1b3-1005-409c-82a9-a072e375d5e9n%40googlegroups.com?utm_medium=email&utm_source=footer>. -- You received this message because you are subscribed to the Google Groups "weewx-user" group. 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