Hi, the issue with negative values occurring as min-values for data elements of type positive / zero-or-positive number, and positive values occurring as max-values for data elements of type negative number have now been fixed in trunk and 2.13.
regards, Lars On Wed, Nov 6, 2013 at 12:00 AM, Jason Pickering < jason.p.picker...@gmail.com> wrote: > Hi Dapo., > > This is just a design issue with DHIS2. There needs to be some better > statistical methods employed to generate the min max, or a means to specify > that the minimum should be zero for all values. There is no linkage between > the value type and the method which the mix-max uses to generate its > values. In our case, we use a combination of R and SQL to calculate > "better" values on a regular basis. A bit of a hack, but the current > methods are simply not working for us either. > > Regards, > Jason > > > > > > On Wed, Nov 6, 2013 at 12:23 AM, Adebusoye Anifalaje <bus...@hisp.org>wrote: > >> Hi all, >> >> To introduce a variation on this theme of generating min-max values: I >> expected that if you set data element number type to Zero of Positive >> Integer this should alter the distribution (in this case skew to the right >> as Jason put it) and avoid the negative minimum values. From the tests I >> have done, this is not happening. >> >> The negative mim values are a real pain, anyone with a solution yet? >> >> Regards, >> >> Busoye >> >> On 31 May 2013, at 14:53, Gulam Khan <gm-k...@criticalsoftware.com> >> wrote: >> >> Hi Dapo, >> If you were to generate the min-max values automatically, insert them >> into the database, and an authorized user was to change them, then they >> would be overwritten. >> >> You can automatically generate these values through the data >> administration module by dataset and orgunit in Data >> Administration->Min-Max Value Generation . The problem is you often end up >> with a lot of dubious values, such as negative numbers. This is a result of >> the Gaussian distribution model which is applied (without taking any >> skewness into effect). I have attached a plot from a real DHIS2 database, >> which show sthat the distribution of many in DHIS2 are skewed left or right >> (more often to the right) . Use of an unbounded, normal distribution for >> calculation of the min-max is therefore not really appropriate. The >> standard deviation approach is also highly sensitive to outliers, which >> also creates problems for the outlier analysis if this approach is used. >> Anyway, I digress. Just wanted to highlight that the in-built functions for >> calculation of the min-max are rather primitive, and may not always lead to >> good results. >> >> I am not so sure about the ability to restrict the time periods for which >> the mix-max is generated. I think you would end up with far too few data >> points to make a meaningful standard deviation. You are really looking for >> the extremes with the min-max, and restricting to such a a narrow time >> interval would probably not give you these extremes. >> >> Regards, >> Jason >> >> >> >> On Thu, Sep 19, 2013 at 11:47 PM, Dapo Adejumo <dapo_adej...@yahoo.com>wrote: >> >>> Hi, >>> >>> It will be great if the generation of min-max values can be automated >>> based on a global setting ( ability to select last 3,6 or 12 months data) . >>> I am curious what happens to these “hard coded” min/max values when the >>> database is set to generate min/max values from the frontend – I will >>> assume they are discarded since they reside in the same table? Or which >>> takes precedence ? >>> >>> Thanks. >>> >>> >>> >>> ................................................ >>> >>> >>> >>> *Regards,* >>> >>> >>> >>> *Dapo Adejumo* >>> >>> *+234803363677* >>> >>> *skype : dapojorge* >>> >>> >>> >>> *From:* Dhis2-devs [mailto:dhis2-devs-bounces+dapo_adejumo= >>> yahoo....@lists.launchpad.net] *On Behalf Of *Jason Pickering >>> *Sent:* Thursday, September 19, 2013 6:28 PM >>> *To:* Juma Lungo >>> *Cc:* dhis2-devs >>> >>> *Subject:* Re: [Dhis2-devs] Setting MinMax Values >>> >>> >>> >>> I think I agree with Lars as well. Our use case was we wanted to >>> restrict values between 0 and 31, and not do it with a validation rule, to >>> provide visual clues during data entry. >>> >>> >>> >>> As an aside, one may also want to calculate these values and save them >>> to the database. The current algorithm uses a standard deviation approach, >>> which is problematic, in that in many cases the data which is typically >>> observed does not follow a normal Gaussian distribution. Other statistical >>> models often provide better estimates of the mix/max, but currently, cannot >>> be calculated automatically by the system. If these values are calculated >>> externally in some statistical package, they can be inserted back into the >>> system (or even automated). >>> >>> >>> >>> Regards, >>> >>> Jason >>> >>> >>> >>> >>> >>> On Thu, Sep 19, 2013 at 6:25 PM, Juma Lungo <jlu...@yahoo.com> wrote: >>> >>> I agree with Lars >>> >>> >>> >>> Lungo >>> >>> >>> ------------------------------ >>> >>> *From:* Lars Helge Øverland <larshe...@gmail.com> >>> *To:* Jason Pickering <jason.p.picker...@gmail.com> >>> *Cc:* dhis2-devs <dhis2-devs@lists.launchpad.net> >>> *Sent:* Thursday, September 19, 2013 2:43 PM >>> *Subject:* Re: [Dhis2-devs] Setting MinMax Values >>> >>> >>> >>> Hi Conrad, >>> >>> >>> >>> the min-max data element is per org unit and data element like you say, >>> so it applies to all current and future periods by definition. I don't know >>> your use-case... but in general one might want to think twice before >>> setting the same max value for all facilities, since they usually have very >>> different catchment population and hence natural variations in numbers. >>> >>> >>> >>> Lars >>> >>> >>> >>> >>> >>> _______________________________________________ >>> Mailing list: https://launchpad.net/~dhis2-devs >>> Post to : dhis2-devs@lists.launchpad.net >>> Unsubscribe : https://launchpad.net/~dhis2-devs >>> More help : https://help.launchpad.net/ListHelp >>> >>> >>> >> >> <skewness.png>_______________________________________________ >> Mailing list: https://launchpad.net/~dhis2-devs >> Post to : dhis2-devs@lists.launchpad.net >> Unsubscribe : https://launchpad.net/~dhis2-devs >> More help : https://help.launchpad.net/ListHelp >> >> >> >> _______________________________________________ >> Mailing list: https://launchpad.net/~dhis2-devs >> Post to : dhis2-devs@lists.launchpad.net >> Unsubscribe : https://launchpad.net/~dhis2-devs >> More help : https://help.launchpad.net/ListHelp >> >> > > _______________________________________________ > Mailing list: https://launchpad.net/~dhis2-devs > Post to : dhis2-devs@lists.launchpad.net > Unsubscribe : https://launchpad.net/~dhis2-devs > More help : https://help.launchpad.net/ListHelp > >
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