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How to transfer a query from R. Calculator to ArcPy

Kostas

Hello,

I am using ArcGis 10.2. I have 3 classified rasters and i want to use the following query from r. calculator:

(rclslope>=45) & (rclmosaic>=2000) & (rclfocal>15) to arc.py

how can i write it?

Is it better to use local - combine tool with arc.py to do it?

Thank you very much.

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Kostas

Thank you very much sir, i ll try it

DanPatterson_Retired

the raster calculator is different that a script that uses rasters in a script. If the script gives you a result and you have a table, then you will have one of 2 values... 1 (where the condition is met) or 0 (where the condition is not met) A smart approach would be to use the Con tool in arctoolbox then if that works, go to the Results window and use that as the snippet for your code see my blog for examples related to Results and other programming tips

Kostas

Mr. Wiens Unfortunately yes they exist!! Grid format also!! For God.

Mr. Patterson so finally we have that:

import arcpy

from arcpy import env

from arcpy.sa import *

env.workspace = "c:/sapyexamples/data"

outCon = Con( ( Raster("rclslope") >= 45 ) & ( Raster("rclmosaic") >= 2000 ) & ( Raster("rclfocal") > 15 ), 1, 0 )

outCon.save("c:/sapyexamples/output/outCon")

Right?

When i am loading it i am getting a raster with an attribute table with only one row and one colour all over the layer. No classes not anything. Why is that?

If i write the same proccedure in Raster Calculator (rclslope>=45) & (rclmosaic>=2000) & (rclfocal>15)

i ll get the result i want, here what am i doing wrong.

DanPatterson_Retired

outCon = Con( ( Raster("rclslope") >= 45 ) & ( Raster("rclmosaic") >= 2000 ) & ( Raster("rclfocal") > 15 ), 1, 0 )

outCon.save("C:/sapyexamples/output/outCon")

Kostas

So we mean something like that?

import arcpy

from arcpy import env

from arcpy.sa import *

env.workspace = "C:/sapyexamples/data"

outCon = Con(("rclslope">=45)&("rclmosaic">=2000)&("rclfocal">15),1)

outCon.save("C:/sapyexamples/output/outcon")

DarrenWiens2

There are lots of arcpy examples using Con here - scroll to the bottom.

Kostas

thanks a lot Mr. Darren Wiens. But i need a little more help if you can. The entire code should seem like;

DarrenWiens2

You could use the Con tool (see this page for relevant examples):

Con(("rclslope">=45)&("rclmosaic">=2000)&("rclfocal">15),1)

This returns a raster with pixel value = 1 which meets the criteria. If you're looking for a way to spatially query pixel values in ArcGIS, that doesn't exist to my knowledge.

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