You're right: it's not mentioned in the Customizing Guide, and it really should be.
I've modified the guide to include a section about the topic. Hopefully it will help. *Including arbitrary expressions <https://weewx.com/docs/customizing.htm#arbitrary_expressions_in_plot>* On Mon, Mar 7, 2022 at 10:01 PM Ian Prescott <[email protected]> wrote: > Hi > Could somebody show me how to correctly display a limit / constant value > on a plot > some time ago I alerted to a post about how to show a constant value in a > plot. > I have searched but I haven't found the right words to find that post again > but I copied it and use it in my skin.conf > [[[daywind]]] > # [[[[windSpeed]]]] > # [[[[windGust]]]] > > # place limit line on graph > [[[[windMax]]]] > # data_type = function | this > # label = ' ' | does > # function_definition = 10.5 | not > # function_type = windSpeed | work > # color = red > > data_type = 10.5 > label = ' ' > color = orange > width = 1 > [[[[windSpeed]]]] > color = 0xb48242 > [[[[windGust]]]] > color = 0x4242b4 > I think it is a useful feature for me and it displays an orange line at > 10.5 > BTW the red line does not show on the plot and no errors appear in the log > (debug=1) > see here at oxleyweather.ddnsfree.com > > Now I would like to display a constant value in another plot. > like this > [[[dayvolt]]] > yscale = 3.6, 4.2, 0.1 > [[[[consBatteryVoltage]]]] > label = Transmitter battery > color = 0xb48242 # blue > # color = 0x4242b4 # red > # place limit line on graph > [[[[voltMin]]]] > data_type = function > label = ' ' > function_definition = 3.7 > function_type = consBatteryVoltage > color = red > # width = 1 > But this doesn't show a red line, and there are no complaints in the log. > > However if I use the wind example I get errors in the log ......... > but not for the wind example ........only about the voltage limit > The Customization Guide under ImageGenerator doesn't give any details > Thanks > > Mar 8 15:46:17 weatherstn weewx[14006] INFO weewx.manager: Added record > 2022-03-08 15:45:00 AEST (1646718300) to database 'weewx.sdb' > Mar 8 15:46:17 weatherstn weewx[14006] INFO weewx.manager: Added record > 2022-03-08 15:45:00 AEST (1646718300) to daily summary in 'weewx.sdb' > Mar 8 15:46:17 weatherstn weewx[14006] DEBUG weewx.reportengine: Running > reports for latest time in the database. > Mar 8 15:46:17 weatherstn weewx[14006] DEBUG weewx.reportengine: Running > report 'SeasonsReport' > Mar 8 15:46:17 weatherstn weewx[14006] DEBUG weewx.restx: > StationRegistry: wait interval (91800 < 604800) has not passed for record > 2022-03-08 15:45:00 AEST (1646718300) > Mar 8 15:46:17 weatherstn weewx[14006] DEBUG weewx.reportengine: Found > configuration file /etc/weewx/skins/Seasons/skin.conf for report > 'SeasonsReport' > Mar 8 15:46:17 weatherstn weewx[14006] DEBUG weewx.cheetahgenerator: > Using search list ['weewx.cheetahgenerator.Almanac', > 'weewx.cheetahgenerator.Current', 'weewx.cheetahgenerator.DisplayOptions', > 'weewx.cheetahgenerator.Extras', 'weewx.cheetahgenerator.Gettext', > 'weewx.cheetahgenerator.JSONHelpers', 'weewx.cheetahgenerator.PlotInfo', > 'weewx.cheetahgenerator.SkinInfo', 'weewx.cheetahgenerator.Station', > 'weewx.cheetahgenerator.Stats', 'weewx.cheetahgenerator.UnitInfo'] > Mar 8 15:46:17 weatherstn weewx[14006] DEBUG weewx.manager: Daily summary > version is 4.0 > Mar 8 15:46:17 weatherstn weewx[14006] ERROR weewx.cheetahgenerator: > Evaluation of template /etc/weewx/skins/Seasons/telemetry.html.tmpl failed. > Mar 8 15:46:17 weatherstn weewx[14006] ERROR weewx.cheetahgenerator: **** > Ignoring template /etc/weewx/skins/Seasons/telemetry.html.tmpl > Mar 8 15:46:17 weatherstn weewx[14006] ERROR weewx.cheetahgenerator: **** > Reason: cannot find 'has_data' while searching for 'year.3.7.has_data' > Mar 8 15:46:17 weatherstn weewx[14006] ERROR weewx.cheetahgenerator: **** > To debug, try inserting '#errorCatcher Echo' at top of template > Mar 8 15:46:17 weatherstn weewx[14006] INFO weewx.cheetahgenerator: > Generated 7 files for report SeasonsReport in 0.29 seconds > Mar 8 15:46:17 weatherstn weewx[14006] DEBUG weewx.manager: Daily summary > version is 4.0 > Mar 8 15:46:17 weatherstn weewx[14006] INFO weewx.imagegenerator: > Generated 19 images for report SeasonsReport in 0.23 seconds > Mar 8 15:46:17 weatherstn weewx[14006] INFO weewx.reportengine: Copied 0 > files to /var/www/html/weewx > Mar 8 15:46:17 weatherstn weewx[14006] DEBUG weewx.reportengine: Report > 'SmartphoneReport' not enabled. Skipping. > Mar 8 15:46:17 weatherstn weewx[14006] DEBUG weewx.reportengine: Report > 'MobileReport' not enabled. Skipping. > Mar 8 15:46:17 weatherstn weewx[14006] DEBUG weewx.reportengine: Report > 'StandardReport' not enabled. Skipping. > Mar 8 15:46:17 weatherstn weewx[14006] DEBUG weewx.reportengine: Report > 'FTP' not enabled. Skipping. > Mar 8 15:46:17 weatherstn weewx[14006] DEBUG weewx.reportengine: Report > 'RSYNC' not enabled. Skipping. > > -- > 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/CAN84nRuRrvwvW5zhONY4n%2B%2BydT74zUiuE%3DP6h9Ej3tdMXpeLRg%40mail.gmail.com > <https://groups.google.com/d/msgid/weewx-user/CAN84nRuRrvwvW5zhONY4n%2B%2BydT74zUiuE%3DP6h9Ej3tdMXpeLRg%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/CAPq0zEB9aUY9zcJC%2B3jN7wEKdS1uy20E3-FseN2zCqvcyawtJw%40mail.gmail.com.
