The scaling of the pressure chart

[Gyvate]

How do I change the scaling of the pressure in the Overview chart ?
I could't make that out from the Chart Definition Language in the WiKi.
The range is from 930 - 1100 hPa - a range unlikely to be covered within 24 hours.
And the plot is therefore often just like a tilted line
I'd rather like it to be between 980 and 1040 or even in a smaller window like 990-1030.
I assume that the compiler automatically increases the plotting range if data required a wider (=higher) window.

Please advise.

[AndyKF650]

Hi there

My initial thought is that this is controlled by the CMX settings for Pressure, mine is set to 980 to 1040, but on CUtils pressure chart this seems to translate to 960 to 1040.
I am not to sure if there is another setting to try. Looking at your historic pressure chart you seem to have an error on 29 May 2021, too high and 27 December 2020, perhaps too low.

[Gyvate]

Looking at your historic pressure chart you seem to have an error on 29 May 2021, too high and 27 December 2020, perhaps too low.

28/29 May 2021 needed correction - 27 December 2020 was correct though. Thanks for the hint.

But still wondering if the chart compiler could be told to start with a different scaling (if current data allows).
It does it with rain all the time even though there were much higher daily rain sums.
Therefore I don't think (but don't know either) that a range defined by historical high/lows plays a role here ....
My charts show a maximum 24 hour history.
In spite of the corrections and a website re-creation the scale is still between 930 and 1140.
The reference site is http://meshka.eu/CUtils48
(the .../CUtils site base (CMX log) data may still need correction at the pointed-to dates)

[HansR]

@Gyvate, @AndyKF650:

Sorry for this unclarity. Yes it should be described in the CDL chapter of the wiki in the paragraph of the Chart Axis.

I will not now describe all axis detail but most axis have adaptive scaling as you probably have noticed.

For the pressure axis it is a pseudo-fixed scale which means the min/max values of the scale are set to the min/max all time records found in alltime.ini. Highcharts itself sets the scale values such that there is a tick at the end of the scale and the min/max values fall between the ticks at the end of the scale. If the pressure gets a lower/higher value the axis will adjust automatically.

The idea is that any barometer you have at home has a fixed scale and with small variations there is little movement of the needle. However when the pressure starts falling/rising significantly it is very obvious. This behaviour is mimicked by CUtils (as far as possible).

@Gyvate: I see that your chart scale goes beyond the values the YADR and the top10 shows as min/max values for pressure. Maybe your alltime records have been set in the past by some peak value, I don't know. But it would be a good idea to set the all time records for pressure in the alltime.ini file to the values found by the top10 values/algorithm. Those are the values found in dayfile. You will have to do that manually since CUtils does not change values in any file owned by CMX.

Hope this helps.
I will modify the wiki with scaling info for the axis.

NOTE: this is not really a new user issue, I think you are also no longer a new user. So please make new threads for new issues from now on. Thanks.

[HansR]

OK. I adjusted the wiki page and I separated the topic from the New User post to a post of its own.

[HansR]

@Gyvate: I notice your min/max pressure values took again their previous extreme values. Those must have been reset by CMX. where does that come from as the dayfile does not have those values. Createmissing possibly?

[Gyvate]

@Gyvate: I notice your min/max pressure values took again their previous extreme values. Those must have been reset by CMX. where does that come from as the dayfile does not have those values. Createmissing possibly?

@HansR
are you looking at the proper site ?
there are two of them with different CMX installations:
http://meshka.eu/CUtils is the unchanged one (station 3)
for http://meshka.eu/CUtils48 (station1) I "tweaked" alltime.ini and it's now between 999-1020 hPa in order to have a proper scaling
I didn't notice a reset here ...
that tweak didn't change the top 10 records

[HansR]

@Gyvate: Ah, indeed, on the map they fall over each other because they have the same (or alkost) coordinates. The second site (CUtils48) is correct. Ok, no problem than

[HansR]

that tweak didn't change the top 10 records

The (Top10) records seem OK to me and are not beyond 1100 hPa.
I assume the alltime records had been set according to a spike?