[GRASS-user] r.quantile: what it exaclty do?

Jarek Jasiewicz jarekj at amu.edu.pl
Fri Jan 2 15:50:01 EST 2009



Dylan Beaudette pisze:
> On Fri, Jan 2, 2009 at 4:55 AM, Jarek Jasiewicz <jarekj at amu.edu.pl> wrote:
>   
>> Hi
>> I tirend used r.quantile on SRTM data for Poland (min value about to 0, max
>> value about to 2500 m a.s.l)
>>
>> r.quantile input=Polska at PERMANENT quantiles=4
>> percentiles=0.001,0.01,0,1,0.25,0.50,0.75,0.90,0.99,0.999 bins=1000000
>>
>> and I recived:
>>
>> 0:0.000000:0.000000
>> 1:0.001000:0.000000
>> 2:0.010000:0.000000
>> 3:0.250000:0.000000
>> 4:0.500000:1.000000
>> 5:0.750000:2.000000
>> 6:0.900000:3.000000
>> 7:0.990000:3.000000
>> 8:0.999000:3.000000
>> 9:1.000000:3.000000
>>
>> It looks like the results are divided by 1000 and rounded to the nearest
>> integer.
>>
>> Did I something wrong?
>>
>> Jarek
>>
>>     
>
> I thought that the user supplies one of [quantiles=] | [percentiles=]
> ... could that be related to the odd output. I have verified (with R)
> that r.quantile can compute correct quantiles... however, on my system
> I need to set bins=100 or so, as the higher i set 'bins' odd things
> would happen.
>
> Glynn should know for sure.
>
> Dylan
>   
Thanks
it really seems that the problem was in default number of bins


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