As a side note, pairing the _stats function with jstat [http://www.jstat.org/] is a nice and easy way to graph min, max, average and std.
Here is an example: http://pastebin.com/3yU3Ncy8 On Thu, Jun 9, 2011 at 11:12 AM, Robert Newson <[email protected]> wrote: > Average isn't going to be possible without introducing compound > rounding errors (which, in my opinion, render the results useless). > > The suggestion to use _stats sounded right to me. That will give you > both the count of items and the sum of those items, perform the final > (single) division in the client to avoid compound rounding errors. > > B. > > On 9 June 2011 18:04, Sean Copenhaver <[email protected]> wrote: >> Yowza, I missed a lot in this thread. Yeah I thought you needed sum, but I >> provided a lot of examples of querying with some test data on your >> stackoverflow question. I hope that helps. It would actually be nice to see >> a built in _avg reduce function though. >> >> >> On Thu, Jun 9, 2011 at 12:39 PM, Robert Newson >> <[email protected]>wrote: >> >>> One minor point, your documents won't sort correctly (and therefore >>> your sums will be wrong). A string of this form "[2011, 6, 7, 10, 55]" >>> will not sort the same as the array you intended [2011, 6, 7, 10, 55]. >>> >>> B. >>> >>> On 9 June 2011 17:36, Fabio Di Bernardini <[email protected]> wrote: >>> > I need to make a chart with hourly sum of values restricted to March. So >>> I >>> > don't need one number with the sum of whole March month. >>> > >>> > >>> > 2011/6/9 David Hardtke <[email protected]> >>> > >>> >> Hi Fabio, >>> >> >>> >> This should work. You can use the _sum builtin as reduce: >>> >> >>> >> "reduce":"_sum" >>> >> >>> >> You then need to query your view with the proper group level and a >>> startkey >>> >> and endkey: >>> >> >>> >> GET >>> >> >>> db/_design/power/_view/watt?group_level=2&startkey=[2011,3]&endkey=[2011,4]&inclusive_end=false >>> >> >>> >> That gives you the sum for the month of March. >>> >> >>> >> >>> >> >>> >> >>> >> On 06/09/11 09:06, Fabio Di Bernardini wrote: >>> >> >>> >>> Il 09/06/2011 17:18, Fabio Di Bernardini ha scritto: >>> >>> >>> >>>> If I have a map function emitting a timestamp as key ad a number as >>> >>>> document, how to get sum of values selecting a date range? >>> >>>> >>> >>> >>> >>> More datails here: >>> >>> >>> >>> >>> http://stackoverflow.com/questions/6294794/how-to-sum-values-of-a-view-in-a-date-range-using-couchdb >>> >>> >>> >> >>> >> >>> > >>> >> >> >> >> -- >> “The limits of language are the limits of one's world. “ -Ludwig von >> Wittgenstein >> > -- Twitter: @eckoit http://eckoit.com - Keep what you hear. http://opendoorstories.com - Create Experiences
