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Re: [Dhis2-users] Generating Min/ Max

 

my test also shows that only the min/max across all values of an org unit
is use for setting mix/max. As this is unlikely to change any soon, I just
want to understand if I can set the min/max values based on my own logic,
and then inject it via the API.

*Rodolfo Meliá*
*Principal  |  *rmelia@xxxxxxxxxxxx
Skype: rod.melia  |  +44 777 576 4090  |  +1 708 872 7636
www.knowming.com

On Mon, Apr 20, 2015 at 2:14 PM, Jason Pickering <
jason.p.pickering@xxxxxxxxx> wrote:

> HI,
>
> I think as Prosper says, it is simply the overall max and min, and this
> can be set by the user, or calculated externally.
>
> Calle, use of standard deviation is problematic for several reasons
> however, mostly because it makes an assumption that the data is actually
> normally distributed, which is not really always the case. This may be
> appropriate for some data elements, but in many cases, it is not an
> appropriate statistical assumption, and results which we have seen after
> often zero inflated or follow something more like a logistical distribution
> (as opposed to a normal distribution).  So applying something like  a
> standard deviation may (and does in the case of DHIS2)  result in many
> negative min values. So, although I think the method of DHIS 1.4 may be
> somewhat better, it still is not really always appropriate, as the
> assumption of a normal distribution is simply not always warranted.
>
> Regards,
> Jason
>
>
>
> On Mon, Apr 20, 2015 at 3:02 PM Calle Hedberg <calle.hedberg@xxxxxxxxx>
> wrote:
>
>> Hi,
>>
>> Sorry, but if the automatic min-max calculation is simply retrieving the
>> historical minimum and maximum values, then that makes little sense and
>> would have no real value.
>>
>> I don't have time to verify it right now, but my assumption has always
>> been that DHIS2 is using a method similar to the one in DHIS 1.4:
>>
>> 1.
>> The user specify a period to be used for the min/max analysis - typically
>> 12-18 months (longer is better in a stable health establishment
>> environment, but a shorter period might be optimal in areas where patient
>> numbers are changing rapidly)
>>
>> 2.
>> The average and standard deviation is calculated for each
>> OrganisationUnit and DataElement combination
>>
>> 3.
>> The min is set to the average minus stdev x constant, max is set to
>> average plus stdev x constant. Typically constants are 1.5 - 2.0  (There is
>> an "Data analysis std dev factor" specified under General Settings - by
>> default set to 2.0. System might be using that).
>>
>> Best regards
>> Calle
>>
>>
>> On 20 April 2015 at 14:49, Rodolfo Melia <rmelia@xxxxxxxxxxxx> wrote:
>>
>>> Thanks Prosper - that makes sense.
>>> I guess that the only way to set a different rule (e.g., Max should be
>>> 150% than previous period) the max will need to be set via an app.
>>>
>>> Are Max/ Min of a Data Element/ Org Unit exposed in the API ?
>>>
>>> R
>>>
>>> *Rodolfo Meliá*
>>> *Principal  |  *rmelia@xxxxxxxxxxxx
>>> Skype: rod.melia  |  +44 777 576 4090  |  +1 708 872 7636
>>> www.knowming.com
>>>
>>> On Mon, Apr 20, 2015 at 1:29 PM, Prosper BT <ptb3000@xxxxxxxxx> wrote:
>>>
>>>> Hi Rodolfo,
>>>>
>>>> Used its before and according to the results we got, it takes the ever
>>>> max and min entered in the selected period for a given dataset.
>>>>
>>>> Regards
>>>>
>>>> On Mon, Apr 20, 2015 at 3:24 PM, Rodolfo Melia <rmelia@xxxxxxxxxxxx>
>>>> wrote:
>>>>
>>>>> I'm trying to understand how does DHIS generates the Min/ Max values
>>>>> for a given Data Element/ Period. The documentation
>>>>> <https://www.dhis2.org/doc/snapshot/en/user/html/ch12s03.html> only
>>>>> makes reference to the fact that Max/Min can be set manually or
>>>>> automatically calculated. When automatically calculated: does anyone knows
>>>>> what is the logic used for setting the values? Twice the average of
>>>>> previous periods?
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> Mailing list: https://launchpad.net/~dhis2-users
>>>>> Post to     : dhis2-users@xxxxxxxxxxxxxxxxxxx
>>>>> Unsubscribe : https://launchpad.net/~dhis2-users
>>>>> More help   : https://help.launchpad.net/ListHelp
>>>>>
>>>>>
>>>>
>>>>
>>>> --
>>>> Prosper Behumbiize, MPH
>>>> Phone:        +256 414 320076
>>>> Cell:             +256 772 139037
>>>>                      +256 752 751776
>>>>
>>>>
>>>
>>>
>>> _______________________________________________
>>>
>> Mailing list: https://launchpad.net/~dhis2-devs
>>> Post to     : dhis2-devs@xxxxxxxxxxxxxxxxxxx
>>> Unsubscribe : https://launchpad.net/~dhis2-devs
>>>
>> More help   : https://help.launchpad.net/ListHelp
>>>
>>>
>>
>>
>> --
>>
>> *******************************************
>>
>> Calle Hedberg
>>
>> 46D Alma Road, 7700 Rosebank, SOUTH AFRICA
>>
>> Tel/fax (home): +27-21-685-6472
>>
>> Cell: +27-82-853-5352
>>
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>>
>> Email: calle.hedberg@xxxxxxxxx
>>
>> Skype: calle_hedberg
>>
>> *******************************************
>>
>>  _______________________________________________
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>>
>

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