Opened 10 years ago

Closed 10 years ago

# [raster] ST_MapAlgebra for Nearest Neighbor how?

Reported by: Owned by: robe Bborie Park medium PostGIS 2.1.0 raster master

## Description

I'm not sure if this is a documentation bug or I'm just missing something.

In the docs

We have the NGB variant marked as deprecated and to use the ST_MapAlgebra function name, but I'm not seeing any examples of NGB in ST_MapAlgebra page: http://postgis.net/docs/manual-dev/RT_ST_MapAlgebra.html

Nor any arguments to denote the size of the neighborhood. I think we are aslo missing some casts as I think the examples some don't work anymore without casting. I'll fix that once I figure out which ones I noticed.

### comment:1 by Bborie Park, 10 years ago

This would be a doc issue. The analogs for defining the neighborhood between ST_MapAlgebraFctNgb and ST_MapAlgebra are:

ngbwidth = distancex

ngbheight = distancey

I know that the neighborhood ops for ST_MapAlgebra are solid as they're in use daily…

### comment:2 by Bborie Park, 10 years ago

There are examples of neighborhood opts in the docs for ST_MapAlgebra. Look at queries 4 and 5 of Examples: Variant 1.

### comment:3 by robe, 10 years ago

Ah okay. I'll output an itemized list describing all the variables like we had in the deprecated so its a bit clearer. I think we need pictures too

### comment:4 by robe, 10 years ago

I added a variablelist and moved a lot of the descriptions to that. Hoepfully that will make the arguments easier to follow: Done at r11099. We'll see how it looks in a bit assuming I didn't offend docbook - http://postgis.net/docs/manual-dev/RT_ST_MapAlgebra.html

### comment:5 by robe, 10 years ago

Resolution: → fixed new → closed

### comment:6 by Bborie Park, 10 years ago

Yeah, I didn't add any figures… the queries work though!

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