Page 1 of 1

Rounding of rainfall data

Posted: Thu 11 Oct 2012 8:20 am
by freddie
My VP has a bucket size of 0.25 mm (strictly, 1/100 of an inch). It looks as if Cumulus displays rainfall totals to 1 decimal place. This I can live with - but the rounding of individual tips is inconsistent. Sometimes it is 0.2 mm displayed, sometimes it is 0.3 mm. This sometimes agrees with what the VP console displays, sometimes it doesn't. Also, when Cumulus totals up rainfall over an hour/day/month/year it appears to use the rounded values - so sometimes an hour with 2 tips will be counted as 0.4 mm, sometimes 0.5 mm and sometimes 0.6 mm. Is there any likelihood that this could be looked at, please?

Re: Rounding of rainfall data

Posted: Thu 11 Oct 2012 8:34 am
by steve
Yes, I've assumed that if you display in mm, you have a mm gauge, so it rounds to 1 dp. Is there a particular reason you aren't using the mm setting for the rain gauge?

At some point I do plan to give users complete control over the number of decimal places displayed and logged, for better or worse. But I don't know when that will be.

Re: Rounding of rainfall data

Posted: Thu 11 Oct 2012 9:17 am
by freddie
The bucket size on my VP is 1/100 of an inch, that's why I use that setting. I don't think there is a mm size for that on the VP console settings.

What you are describing (re: user-defined number precision) sounds really useful - thanks :-)

Re: Rounding of rainfall data

Posted: Thu 11 Oct 2012 9:28 am
by steve
freddie wrote:The bucket size on my VP is 1/100 of an inch, that's why I use that setting. I don't think there is a mm size for that on the VP console settings.
The usual procedure for metric users is to modify the rain gauge so that it tips at 0.2 mm rather than 0.01 in; Davis supply the necessary item for the modification with the station. Having applied the modification, you then tell the console (in the setup) that you're using a metric rain gauge rather than imperial. The procedure is described in the manual(s).

Re: Rounding of rainfall data

Posted: Thu 11 Oct 2012 12:49 pm
by freddie
Ah OK I didn't realise you could do that. I will take a look over the weekend. Thanks for the advice.