[postgis-users] ST_Quantile

[Joan]

The 0.75 is the quantile.

I will report the bugs. Thanks for the help/info.

Joan

On 27 January 2012 20:31, Stephen Woodbridge <woodbri at swoodbridge.com>wrote:

> Joan,
>
> Looking at the function the Bborie posted:
>
>
> st_quantile(rastertable text, rastercolumn text, nband int DEFAULT
>   1, exclude_nodata_value boolean DEFAULT TRUE, quantiles double
>   precision[] DEFAULT NULL)
>
> The 3rd parameter is the band number. What is the 0.75 supposed to
> represent? My guess is that is getting truncated to 0 and it is trying to
> process band=0 which might not be valid.
>
> But it should not crash, so please write two bugs against this:
> 1. for the missing doc
> 2. for the crash if you enter 0.75
>
> Thanks,
>  -Steve
>
>
> On 1/27/2012 2:19 PM, Joan wrote:
>
>> Hi Steve,
>>
>> I have gotten the same problem (db server stopped running).
>>
>> Joan
>>
>> On 27 January 2012 20:05, Stephen Woodbridge <woodbri at swoodbridge.com
>> <mailto:woodbri at swoodbridge.**com <woodbri at swoodbridge.com>>> wrote:
>>
>>    Joan,
>>
>>    I've never used these function, but try doing:
>>
>>    select st_quantile('kbd_ext', 'rast', 0.75);
>>
>>    Since you probably do not want this called once for every row in the
>>    table.
>>
>>    -Steve
>>
>>
>>    On 1/27/2012 2:03 PM, Joan wrote:
>>
>>        Hi Bborie,
>>
>>        This is my query and it crashes the db server.
>>        select st_quantile('kbd_ext', 'rast', 0.75) from kbd_ext limit 10;
>>
>>        Joan
>>
>>        On 27 January 2012 19:14, Bborie Park <bkpark at ucdavis.edu
>>        <mailto:bkpark at ucdavis.edu>
>>        <mailto:bkpark at ucdavis.edu <mailto:bkpark at ucdavis.edu>>> wrote:
>>
>>            Hey Joan,
>>
>>            Assuming your whole coverage is in a table, you should use the
>>            table/column version of ST_Quantile (which by the looks of it
>> is
>>            undocumented for some reason).
>>
>>            The function definition of ST_Quantile(rastertable,
>>        rastercolumn) is...
>>
>>            st_quantile(rastertable text, rastercolumn text, nband int
>>        DEFAULT
>>            1, exclude_nodata_value boolean DEFAULT TRUE, quantiles double
>>            precision[] DEFAULT NULL)
>>
>>            At the moment an aggregate version of ST_Quantile (and the
>> other
>>            basic stats functions) does not exist.  It is expected that
>>        one will
>>            be written for PostGIS 2.1 assuming dev-time is available.
>>
>>            -bborie
>>
>>
>>            On 01/27/2012 09:06 AM, Joan wrote:
>>
>>                Hi,
>>
>>                I would like to find the quantile values of a whole raster
>>                coverage, but
>>                ST_Quantile returns quantile values of each tile. Which
>>        would be
>>                the best
>>                method to approximate the quantile value of the whole
>>        coverage?
>>
>>                Regards,
>>
>>                Joan
>>
>>
>>
>>
>>                ______________________________ _________________
>>                postgis-users mailing list
>>                postgis-users at postgis. refractions.net
>>        <http://refractions.net>
>>        <mailto:postgis-users at postgis. refractions.net
>>
>>        <mailto:postgis-users at postgis.**refractions.net<postgis-users at postgis.refractions.net>
>> >>
>>        http://postgis.refractions. net/mailman/listinfo/postgis- users
>>
>>        <http://postgis.refractions. net/mailman/listinfo/postgis- users
>>        <http://postgis.refractions.**net/mailman/listinfo/postgis-**users<http://postgis.refractions.net/mailman/listinfo/postgis-users>
>> >>
>>
>>
>>            --
>>            Bborie Park
>>            Programmer
>>            Center for Vectorborne Diseases
>>            UC Davis
>>            530-752-8380
>>        bkpark at ucdavis.edu <mailto:bkpark at ucdavis.edu>
>>        <mailto:bkpark at ucdavis.edu <mailto:bkpark at ucdavis.edu>>
>>
>>
>>            ______________________________ _________________
>>            postgis-users mailing list
>>            postgis-users at postgis. refractions.net <http://refractions.net
>> >
>>        <mailto:postgis-users at postgis. refractions.net
>>
>>        <mailto:postgis-users at postgis.**refractions.net<postgis-users at postgis.refractions.net>
>> >>
>>        http://postgis.refractions. net/mailman/listinfo/postgis- users
>>        <http://postgis.refractions. net/mailman/listinfo/postgis- users
>>        <http://postgis.refractions.**net/mailman/listinfo/postgis-**users<http://postgis.refractions.net/mailman/listinfo/postgis-users>
>> >>
>>
>>
>>
>>
>>
>>        ______________________________ _________________
>>        postgis-users mailing list
>>        postgis-users at postgis. refractions.net
>>        <mailto:postgis-users at postgis.**refractions.net<postgis-users at postgis.refractions.net>
>> >
>>        http://postgis.refractions. net/mailman/listinfo/postgis- users
>>        <http://postgis.refractions.**net/mailman/listinfo/postgis-**users<http://postgis.refractions.net/mailman/listinfo/postgis-users>
>> >
>>
>>
>>    ______________________________ _________________
>>    postgis-users mailing list
>>    postgis-users at postgis. refractions.net
>>    <mailto:postgis-users at postgis.**refractions.net<postgis-users at postgis.refractions.net>
>> >
>>    http://postgis.refractions. net/mailman/listinfo/postgis- users
>>    <http://postgis.refractions.**net/mailman/listinfo/postgis-**users<http://postgis.refractions.net/mailman/listinfo/postgis-users>
>> >
>>
>>
>>
>>
>> ______________________________**_________________
>> postgis-users mailing list
>> postgis-users at postgis.**refractions.net<postgis-users at postgis.refractions.net>
>> http://postgis.refractions.**net/mailman/listinfo/postgis-**users<http://postgis.refractions.net/mailman/listinfo/postgis-users>
>>
>
> ______________________________**_________________
> postgis-users mailing list
> postgis-users at postgis.**refractions.net<postgis-users at postgis.refractions.net>
> http://postgis.refractions.**net/mailman/listinfo/postgis-**users<http://postgis.refractions.net/mailman/listinfo/postgis-users>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/postgis-users/attachments/20120127/f8244acd/attachment.html>