Author 
Message 
darrog

Post subject: Re: Means Rules help and advice Posted: Fri Jan 04, 2013 2:05 pm 

Weather Nut 

Joined: Mon Nov 02, 2009 10:23 pm Posts: 1907 Location: Maulds Meaburn, Cumbria
Altitude: 183
Weather Station: Davis VPro2

I did previously mention this:
So how do you work out seasonal and yearly averages then?
A  the sum of the mean temps divide by 12 and then apply those rules re 0.05, 0.15, etc or
B  the sum of the mean min/max divide by 2 and then apply the above rules?
But there is a C and 2012 as provided an example of when it matters!
using A my yearly mean is 8.24c  gets rounded down to 8.2c using B my yearly mean is 8.25c  gets rounded up to 8.3c
And at this point I did think that if a monthly temp is calculated by B, then it should follow that a yeraly mean should be calculated the same way (and not use A)
But I now expect you all to use C which is the only true way  but takes a little more time!
C  is the total of all 365/6 min' temps + the total of all the 365/6 mean max' temps divide by 730/732
And guess what  using C my yearly mean is 8.26c  rounded up to 8.3c
I now expect you all to check and if necessary revise all your data!!!!!!!!!!!!!!!!!!!!!!!!!!!!
_________________ Darren Rogers  he who submits the most interesting posts, AKA Mr Data Maulds Meaburn





Paul C

Post subject: Re: Means Rules help and advice Posted: Fri Jan 04, 2013 8:19 pm 

Professor 

Joined: Mon Nov 02, 2009 8:52 pm Posts: 7837 Location: Brampton
Altitude: 117m
Weather Station: Davis VP2





Paul C

Post subject: Re: Means Rules help and advice Posted: Fri Jan 04, 2013 8:26 pm 

Professor 

Joined: Mon Nov 02, 2009 8:52 pm Posts: 7837 Location: Brampton
Altitude: 117m
Weather Station: Davis VP2





darrog

Post subject: Re: Means Rules help and advice Posted: Sat Jan 05, 2013 12:40 pm 

Weather Nut 

Joined: Mon Nov 02, 2009 10:23 pm Posts: 1907 Location: Maulds Meaburn, Cumbria
Altitude: 183
Weather Station: Davis VPro2

Paul  it's simple really and also obvious.
you use all 30/31 min temps in a month to calculate a mean min and then ditto for the mean max  you now add them all together. then use that totals and divide by 60/62 to calculate your mean temp for the month  then 'throw to the odd' if necessary.
To calculate the yearly mean min/max and then mean is just the same, but now instead of 60/62 numbers you have 730/732.
_________________ Darren Rogers  he who submits the most interesting posts, AKA Mr Data Maulds Meaburn





darrog

Post subject: Re: Means Rules help and advice Posted: Sat Apr 06, 2013 1:01 pm 

Weather Nut 

Joined: Mon Nov 02, 2009 10:23 pm Posts: 1907 Location: Maulds Meaburn, Cumbria
Altitude: 183
Weather Station: Davis VPro2

I'm going to have to amend this really.
after March threw up another oddity (a mean min of 1.6c and a max' of 4.9c = 1.65c which should be thrown to the odd of 1.7c  why did my spread sheet show a mean of 1.6c  answer was that the 62 min/max readings actually = 1.6489c  so it rounded it down!!!
So anyway, Philip Eden tells me that he always quotes his figures to two decimal points and which really is quite logical.
so from now on i will quote my mean to 2 decimal points  so March 2013 is obviously 1.65c
now going through the process of changing back all my other months to two decimal places  quite easy really as i had done 50% of them that way anyway
_________________ Darren Rogers  he who submits the most interesting posts, AKA Mr Data Maulds Meaburn




