[raster] ST_Approx raster stats functions are not documented

[pracine]

And the sample_percent parameter is not listed as possible parameter for the all the stats functions.

[robe]

push back if you feel you'll get to it before then.

[sunveersingh]

Hello there, I would like to work on this, would love if someone can get me started on this.

[robe]

sunveersingh,

Hopefully this will help - if you have any more questions, join our development mailing list.

SHORT ANSWER 1) For new functions (even if they are not knew but just aren't documented) use this template

​https://trac.osgeo.org/postgis/browser/trunk/doc/template.xml

2) Attach the updated file to this ticket.

LONG ANSWER

1) Join our developer mailing list especially if you have questions - ​https://lists.osgeo.org/mailman/listinfo/postgis-devel

2) Don't be shy asking questions on the list. No one should bite you even if you ask a stupid question. We all ask stupid questions. If per chance someone SHOULD bite you, I'll bite them back and you can bite them too :).

3) For documentation - we use docbook, which is an xml format - the raster functions are all documented in doc/reference_raster.xml and general raster usage manual is doc/using_raster_dataman.xml

These you can pull from any of our git and svn mirrors listed way at the bottom of this page - ​https://postgis.net/source/ (or the latest tar ball ​https://postgis.net/stuff/postgis-3.0.0dev.tar.gz )

Use the trunk version

4) When you make changes to existing function - you can create a patch to the file and attach it to this ticket. git or svn or regular old patch are all fine.

For new functions such as this one -- just the body of the functions is sufficient - and you follow the format of our template - ​https://trac.osgeo.org/postgis/browser/trunk/doc/template.xml

You can attach each as separate file to this ticket or just as a single file, repeating the template format of each new function.