[postgis-users] Reclassify a Slope Surface

JamesH james.holmes at newcastle.ac.uk
Tue Apr 10 09:43:06 PDT 2012

Hi all,

I am trying to reclassify a slope surface with a reverse normalisation
(lower the slope value, the closer to 1 it becomes).

It can be done in ArcGIS in the Raster Calculator using:
(0.404234915971756 - "slope") / 0.404234915971756 
where 0.404234915971756 is the maximum value (minimum value of the data is
zero so I don't need to include this in the calculation).

Wanting to recreate this process in PostGIS so can anyone advise on how I
could do the calculation for:
(max. value - cell value)/ max. value for each cell in the raster?
Cannot get my head around it.

Much Appreciated

GIS Undergraduate
View this message in context: http://postgis.17.n6.nabble.com/Reclassify-a-Slope-Surface-tp4763035p4763035.html
Sent from the PostGIS - User mailing list archive at Nabble.com.

More information about the postgis-users mailing list