Hi there. The current design is to take the mean, and calculate n-standard deviations away from the mean, for a given data element/orgunit/catcombo set of data values. If the data value is set to be zero or positive integer, and can never have a negative value and does not follow a normal distribution, then flooring the projected min/max at zero makes little sense, if the distribution is not normal. Another distribution would be required to determine what the accepted min/max actually are (logistical, zero-inflated model, etc) if the actual distribution is not normal.
But per the bug report, the application does what it is supposed to do, namely calculate the theoretical min/max based on a stastical routine, which itself may not be valid without confirming that the distribution in question actually is normal or not. Regards, Jason On Fri, Sep 18, 2015 at 11:57 AM, Lars Helge Øverland <larshe...@gmail.com> wrote: > This is not a design flaw. It depends on the data element value type > property. The default value type is "number", for which negative values > are perfectly valid. One can set the value type to "Positive number", in > this case the min-max values will never be less than zero. > > ** Changed in: dhis2 > Status: Opinion => Invalid > > -- > You received this bug notification because you are a member of DHIS 2 > developers, which is subscribed to DHIS. > https://bugs.launchpad.net/bugs/1065014 > > Title: > Min/Max generation goes into negative > > Status in DHIS: > Invalid > > Bug description: > A very minor bug, but the min/max generation algorithm (which I assume > is some std. dev) sometimes leads the minimum to be a negative number. > Probably not an issue per se for data quality, as the alternative > would be to set it to 0 (unless there is a reason why you would enter > negative numbers), but the chart you get when you double-click a data > entry field is then skewed and does not look very sensible. In extreme > cases, with a few very high values and a few months with very low (as > when you have campaigns or hand-outs), the minimum can be down to > minus a lot. > > To manage notifications about this bug go to: > https://bugs.launchpad.net/dhis2/+bug/1065014/+subscriptions > > _______________________________________________ > 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 > -- Jason P. Pickering email: jason.p.picker...@gmail.com tel:+46764147049
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