dhis2-devs team mailing list archive

[Jason Pickering <jason.p.pickering@xxxxxxxxx>]

Hi Robin,
You lost me. Could you maybe give a somewhat simpler example by what you
mean by an "intermediary calculation"?

I am not sure exactly what you are trying to acheive, but what I can say is
that in certain cases, I have had to write my own calculation methods for
certain indicators which are basically impossible to calculate with the
current implementation in DHIS2. It works fine for simple sums, averages,
and other types of statistical things (standard deviation, etc), but for
instance, if you want to calculate other statistical properties (skewness,
kurtosis) of a given set of values, there is not a way to do it directly
with DHIS2. Also, certain indicators depend on component parts, and cannot
be calculated the way DHIS2 does it, by first summing up the numerator and
denominator and then dividing it, as opposed to calculating a non-weighted
average of compulsory pairs of data. What I am getting at, is that you may
have to write your own calculation methods, depending on how complex they
are.

Regards,
Jason


On Thu, Sep 11, 2014 at 4:20 PM, Robin Martens <martens@xxxxxxx> wrote:

>  Hi Jason,
>
>
>
> To pick up the point again, there's an additional question I've been
> looking at.
>
>
>
> Even if disaggregated indicator reporting is burdensome (as you explain
> below), it is sometimes necessary for correct aggregated indicator
> calculations (the most obvious one the use of weighted averages) to have
> "intermediary calculations" according to dimensions in the indicator
> calculation, which can then be aggregated over the whole table to obtain
> the total aggregated indicator value. Even in these intermediary
> calculations, however, the data is not available for calculation, returning
> zero as a result.
>
>
>
> The conclusion is that the current way of indicator calculation not only
> complicates (if not makes impossible in many cases) calculation of
> indicators per custom dimension, but also making impossible the correct
> calculation of indicators over period and orgunit dimension when any
> intermediary calculation over custom dimensions is necessary.
>
>
>
> Can you confirm this?
>
>
>
> If true, is it hard to modify the calculation method to simply pick the
> one-level-higher value of a data element whenever no disaggregated value
> exists? With existing I don't mean NULL or zero, but rather not defined
> (the dimension does not exist).
>
>
>
> Robin
>
>
>
> *From:* Jason Pickering [mailto:jason.p.pickering@xxxxxxxxx
> <jason.p.pickering@xxxxxxxxx>]
> *Sent:* 10 September 2014 17:55
> *To:* Robin Martens
> *Cc:* Lars Helge Øverland; dhis2-users@xxxxxxxxxxxxxxxxxxx; dhis2-devs
> *Subject:* Re: [Dhis2-devs] DHIS2 - Indicator calculation over dimensions
>
>
>
> Hi Robin,
>
> It has been a discussed, and certainly not a bug. See a related thread
> here (https://lists.launchpad.net/dhis2-devs/msg27571.html) for a similar
> discussion on validation rules. It is essentially the same as indicators.
> What you will have to do is to create seperate indicator for each and every
> combination which you need. It can be painful, but the only way really
> which I know at the moment.
>
>
>
> Feel free to file a blueprint here. https://blueprints.launchpad.net/dhis2
>
>
>
> Regards,
>
> Jason
>
>
>
>
>
> On Wed, Sep 10, 2014 at 5:37 PM, Robin Martens <martens@xxxxxxx> wrote:
>
> Dear all,
>
>
>
> I've been testing the indicator calculation algorithm and noticed
> something particular of which I'm not sure if it's a bug or a deliberate
> development choice.
>
>
>
> Indicators are not explicitly defined per category such as data elements
> but the reporting tools allow a disaggregated indicator calculation, which
> is definitely very useful. In a specific example, I want to know how many
> people were vaccinated this year and I have 3 kinds of vaccinations: A, B,
> and C. I have two data elements: the total population and the national
> vaccination levels (in %), with a custom category "vaccination type" which
> can be A, B, or C.
>
>
>
> My indicator would be "total population" x "national vaccination level
> (total)". That works fine when put in a pivot table.
>
>
>
> However, when trying to disaggregate the indicator calculation by adding
> my custom category to the pivot table, I don't have any values anymore. It
> seems the reason is that the "total population" data element does not have
> the "vaccination type" category (which seems logical) and therefore isn't
> found by the calculation algorithm. As a result, my table is empty. It
> seems useful that the algorithm would take the aggregated value (for
> population) available in such cases.
>
>
>
> Another example is over the period dimension: my population is a yearly
> value, so when calculating an indicator on a monthly basis, instead of
> taking the available yearly value, he takes zero.
>
>
>
> So my question: is this a deliberate choice in the development, a bug, or
> an idea for a future system improvement?
>
>
>
> Kind regards,
>
>
>
> Robin
>
>
>
>
>
>
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>
>
>
> --
>
> Jason P. Pickering
> email: jason.p.pickering@xxxxxxxxx
> tel:+46764147049 <+46764147049>
>



-- 
Jason P. Pickering
email: jason.p.pickering@xxxxxxxxx
tel:+46764147049