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I want to use Multiple Ring Buffer (MRB) tool to create multiple donuts, but when I use NONE dissolve and outside polygon it cuts only input buffer from all created and I want it to cut first ring from the second one created. For better understanding: I create 3 buffers - 1km, 5km, 10km First is continuous from starting point and I use it as input for MRB tool. 2nd and 3rd created via MRB: 2nd is what I want because tool dissolves and is outside it. 3rd - I want to have hole with 5km radius=cuted 2nd buffer not 1st.

I know I can do it creating one after another but maybe there is way to make it in one operation? I assume that there is small (?) change of python code needed but I don't know where and how :(

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    Aren't they donuts already? – FelixIP Sep 26 '17 at 14:30
  • Yes, they are but I want the donut hole to be larger every time. Like smaller donut cuts next/bigger one. And now they have the same size of hole. – KaBi Sep 27 '17 at 6:29
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I've written some python code a few years ago which creates donuts; you would wire it up to a script interface or you can hard wire the input parameters

'''
Title: Create donut rings around points

Description: Takes as input the distance of the inner and outer ring and creates a donut polygon around it.

Limitations: Tool expects units of point dataset to be in meters.

Created: 19/9/14
'''
import arcpy
import sys

# Set environment settings
arcpy.env.addOutputsToMap=True
arcpy.env.overwriteOutput = True

def main():
    try:
        # Get parameters
        layer = arcpy.GetParameterAsText(0) # Layer
        pointID = arcpy.GetParameterAsText(1) # Unique ID field
        innerBuff = float(arcpy.GetParameterAsText(2)) # Inner ring distance
        outerBuff = float(arcpy.GetParameterAsText(3)) # Outer ring distance
        outFC = arcpy.GetParameterAsText(4) # Output FeatureClass

        # Check if parameters are sensible
        if innerBuff <= 0:
            arcpy.AddWarning("The inner buffer must be greater than zero!")
            return
        if outerBuff < innerBuff:
            arcpy.AddWarning("The outer buffer must be larger than in the inner buffer value!")
            return

        features = []
        ids =[]

        # Create a cursor over the points and build donuts
        arcpy.AddMessage("Creating donuts...")
        with arcpy.da.SearchCursor(layer, ['SHAPE@', pointID]) as cursor:
            for row in cursor:
                geom = arcpy.PointGeometry(row[0].getPart(0))
                ID = row [1]
                inBuff = geom.buffer(innerBuff)
                outBuff = geom.buffer(outerBuff)
                donut = outBuff.symmetricDifference(inBuff)
                features.append(donut)
                ids.append(ID)

        # Write data to new FeatureClass
        arcpy.AddMessage("Writing features to output dataset...")
        arcpy.CopyFeatures_management(features, outFC)
        arcpy.MakeTableView_management(outFC,"tv")
        arcpy.AddField_management("tv","ID","LONG")
        x = 0
        with arcpy.da.UpdateCursor("tv",['ID']) as cursor:
            for row in cursor:
                row[0] = ids[x]
                x+=1
                cursor.updateRow(row)

        # Set output
        arcpy.SetParameterAsText(4,outFC)

    except Exception as e:
        # Report error
        arcpy.AddError(str(e))
        sys.exit("Failed to Process")

if __name__ == '__main__':
    main()

You would wire up the script as below:

Tool script properties

When you run this script it would generate output as shown below:

Example output

  • I have problem during adding this script as a tool in ArcToolbox. What should I pick as Data Type for ring distances, I've tried String, Linear Unit, Double and all have the same error comment: could not convert string to float. And is there a possibility to create multiple rings? – KaBi Sep 27 '17 at 6:57
  • @KaBi I have amended my question with an image, also made a small tweak to the code for innerBuff. – Hornbydd Sep 27 '17 at 11:03
  • thak you, I've skipped adding ID Field, my mistake. Once again thanks! – KaBi Sep 27 '17 at 11:51

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