Just seen this thread, and this is something that somewhat annoyed me as
well, since all the extra digits cluttered up the database viewing. I
'solved' (got around) it by specifying the precision in the column
definitions since MySQL allows this for float, real and double precision.
Couldn't the schema just be altered to specify the precision for all fields
and make weewx more human friendly? Most columns only require at most 2
decimals, and many 0 or 1 for practical purposes, and weewx remains
oblivious to the column definition change. I changed the schema in mesowx
with no issues so it should work for weewx.
On Friday, 12 February 2016 15:11:38 UTC+2, Pat O'Brien wrote:
> Thanks for the explanation. It all makes sense, especially laid out like
> that. Many areas in play with the observations, so I'm glad to see I'm
> doing it right!
>
>
> On Friday, February 12, 2016 at 8:03:53 AM UTC-5, mwall wrote:
>>
>> On Thursday, February 11, 2016 at 7:28:24 PM UTC-5, Pat O'Brien wrote:
>>
>> I was having a look in the database today, and noticed that a lot of the
>>> archive records and the archive_day_* tables have observations with 12
>>> decimals. Seems to be a bit long.
>>>
>>> So I'm just checking to see if my driver should control the float length
>>> (maybe _packet['windSpeed'] = '{0:.2f}'.format( data["windSpeed"] )
>>> this is untested) or is this supposed to be handled within weewx
>>> somewhere and I have it configured incorrectly?
>>>
>>
>> hi pat,
>>
>> you are doing it right - using float() is the appropriate way to convert
>> from string.
>>
>> precision (number of decimal places) shows up in a few places, including:
>>
>> 1) how the database stores a REAL number. nothing to do here. it is
>> what it is.
>>
>> 2) how your database browser displays a REAL number. some database
>> browsing tools let you specify how many decimal places you want to see,
>> some even on a per-column basis. this does not affect the data - just what
>> you see.
>>
>> 3) how weewx (in python) represents a float. nothing to do here. it is
>> what it is.
>>
>> 4) how weewx displays a float. this is an issue when writing a weewx
>> template. use the cheetah/python formatting to display the number of
>> decimal places you want to see.
>>
>> 5) how weewx uploads a float to wunderground, etc. this is only an issue
>> if you are writing an uploader - an extension that uploads data. values
>> are typically converted to a string then sent using http POST or similar
>> mechanism. use python formatting in your uploader to specify the number of
>> decimal places that the destination requires.
>>
>> m
>>
>
