[postgis-users] raster map algebra question(s)

[Stephen Crawford]

Thanks to all who helped me on my previous raster output questions; I 
now have a better handle on what I can (and can't) do.

How can I do map algebra across raster tables?  I have a db of raster 
tables (all the same extend) with weather variables by date.  I have a 
number of ways i want to use these data, but in the initial case I would 
like to, as an example, create a new raster table where the data value 
at each cell is the average of the previous day's values.  Any thoughts?

Thanks,
Steve

-- 
Stephen Crawford
Center for Environmental Informatics
The Pennsylvania State University