Hi Elliot,
The median isn't the mean of the min and max (though that was fun to say).
Wikipedia says it well:
"the median is the numerical value separating the higher half of a data
sample, a population, or a probability distribution, from the lower half.
The median of a finite list of numbers can be found by arranging all the
observations from lowest value to highest value and picking the middle one
(e.g., the median of {3, 3, 5, 9, 11} is 5). If there is an even number of
observations, then there is no single middle value; the median is then
usually defined to be the mean of the two middle values"
peace,
s
On Tue, Jul 22, 2014 at 10:27 AM, Ivar Nesje <[email protected]> wrote:
> According to Julia median is defined as
>
> n = length(v)
> if isodd(n)
> return middle(select!(v,div(n+1,2)))
> else
> m = select!(v, div(n,2):div(n,2)+1)
> return middle(m[1], m[2])
> end
>
> Ivar
>
> kl. 16:03:47 UTC+2 tirsdag 22. juli 2014 skrev Elliot Saba følgende:
>>
>> Reading your post, I'm a little confused Iain. You state:
>>
>> If we consider only packages with at least 1 package depending on them,
>> we find the median to be 3 dependent packages but the mean to be 10.5. This
>> is due to the 15 or so packages with more than 30 dependent packages.
>>
>> Now, I'm not the best at statistics, but isn't the median of *x* defined
>> as *(min(x) + max(x))/2*? If that is the case, (and assuming that we
>> don't have negative package dependency counts) I don't see how the median
>> can be 3, but the mean be 10.5. Perhaps you meant the mode was 3?
>> -E
>>
>>
>> On Tue, Jul 22, 2014 at 9:55 AM, Iain Dunning <[email protected]> wrote:
>>
>>> Hah, yeah, strangely relevant.
>>> PkgEval runs nightly (around 1am US Eastern), but obviously with so many
>>> people using Julia there is a lot of room for chaos inbetween runs.
>>>
>>>
>>> On Tuesday, July 22, 2014 7:58:46 AM UTC-4, Tomas Lycken wrote:
>>>>
>>>> Look what my RSS reader just picked up! =)
>>>>
>>>> http://iaindunning.com/2014/pkg-deps.html
>>>>
>>>> // T
>>>>
>>>> On Tuesday, July 22, 2014 12:37:59 PM UTC+2, Tomas Lycken wrote:
>>>>>
>>>>> I still think the best way to resolve things if you should encounter
>>>>> problems, is to notify the maintainers. Most people in this community
>>>>> respond surprisingly fast =)
>>>>>
>>>>> There is some automated testing going on already, mainly thanks to
>>>>> [Iain Dunning](https://github.com/IainNZ)'s amazing work with
>>>>> PackageEvaluator and related tools. For example, if you click "more
>>>>> options" on pkg.julialang.org and then "Show package ecosystem
>>>>> statistics for Julia nightly...", you'll see some great data showing the
>>>>> current (and past) state of the entire ecosystem. You'll notice a few dips
>>>>> in the green curve, when changes somewhere suddenly broke a lot of stuff
>>>>> everywhere - and you'll also see that most of it was resolved in a matter
>>>>> of a few days. This happened because semi-automated issues were filed by
>>>>> the system against the packages when they broke, and maintainers were
>>>>> quick
>>>>> to fix whatever they needed.
>>>>>
>>>>> In the case of your problems - someone tagging a version without
>>>>> specifying a correct dependency - that will also be picked up by PkgEval,
>>>>> and the maintainer will be notified. However, since PkgEval only runs
>>>>> every
>>>>> now and then, and since quite a lot of users today "live on the edge" (and
>>>>> actively report issues when they find them) it's not uncommon that
>>>>> problems
>>>>> like this are picked up by users before PkgEval notices them. It's very
>>>>> likely that, as the ecosystem matures and stabilizes, this problem won't
>>>>> be
>>>>> a problem anymore...
>>>>>
>>>>> // T
>>>>>
>>>>> On Tuesday, July 22, 2014 11:47:32 AM UTC+2, Andreas Lobinger wrote:
>>>>>>
>>>>>> Hello colleagues,
>>>>>>
>>>>>> On Monday, July 21, 2014 4:53:17 PM UTC+2, Tomas Lycken wrote:
>>>>>>>
>>>>>>> I think this problem must be resolved by better practices among
>>>>>>> package maintainers: in short, the goal must be that as long as you only
>>>>>>> use (the latest) tagged versions of any packages, everything should Just
>>>>>>> Work (TM). That means, in short, that if a package maintainer adds
>>>>>>> functionality that depends on some specific addition to a different
>>>>>>> package, it is up to that package maintainer to make sure *not* to
>>>>>>> tag a new version until the dependency package has tagged one, in which
>>>>>>> the
>>>>>>> new behavior is included, so the dependency can be correctly specified.
>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>> ... in an ideal world. All that we use around julia has a version
>>>>>> number less than 1.0 so hiccups are expected (at least by me). The
>>>>>> question
>>>>>> was rather how i can help myself and if there is some undocumented work
>>>>>> assumption. If i ever publish a package i'll try hard to follow your
>>>>>> advice.
>>>>>>
>>>>>> This interdependency things showed up also in the great
>>>>>> julia-graphics thread on julia-dev. Maybe some automatic testing could
>>>>>> help? Maybe some dependency graph could be extracted out of the METADATA?
>>>>>>
>>>>>> Wishing a happy day,
>>>>>>
>>>>>>
>>>>>
>>
