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I have 2000+ point shape files. These are all GPS tracks. I want to calculate the distance from each point to the nearest feature (road, train line, restaurant etc) within a 30 meter radius. I am using Near feature from proximity analysis in ArcGIS. I am facing two problems.

  1. Using batch processing one can add as many input rows in Near feature tool box as s/he wants. But this requires selecting each file one by one which is time consuming especially when there are thousands of files. So I tried using a python scripting as follows. But after processing the result is written in the same file. I want to write the table separately. How can I do that?
  2. In case I want to add different columns for each features say road, train network for each point record in a file using near feature how can I do that?

Currently, I am using the following python code but all the output are generated on the current file. I want to write it separately (I mean I want to generate a new table/file after near_analysis)

import arcpy # Import arcpy module # path where all my point shp files are kept arcpy.env.workspace = r'C:\ArcGIS sample data\' #feature to which distance will be calculated nearFeature_shp = 'C:\\GIS route network\\road.shp' # looping through all the files for file in arcpy.ListFeatureClasses (): # Process: Near arcpy.Near_analysis(file, nearFeature_shp , "30 Meters", "LOCATION", "ANGLE")
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  • Would you mind formatting that up a bit (use the {} button to indicate that it's code). The near information is appended to the end of the features that are processed, so what's being overwritten? Commented Aug 21, 2014 at 5:08
  • When I will use different feature followed by the first one then the earlier near columns are overwritten. Say I first used road network as near feature. Next I want to use rail network. So for each point there will be two near features- distance to Road and Rail network within 30 m radius. Commented Aug 21, 2014 at 5:11
  • Oh, that explains it. Use AddField_management to add fields road_near and rail_near and CalculateField_management to copy the values there. Commented Aug 21, 2014 at 5:25
  • Thanx Michael. How do I copy each shp file appending '_road' and write it to a separate folder through loop using python. Say if my original shape file is gpsTrack1.shp I want to process the near operation on it and write the result/processed file in a different folder as gpsTrack1_road.shp. Likewise it should iterate through the loop for all the files. I have modified little bit my for loop for copying the files but this is not working. Commented Aug 21, 2014 at 5:27
  • There are a few ways, FeatureClassToFeatureClass_conversion is possibly the best, CopyFeatures_management works well if you have a layer with a selection or Copy_management is fairly basic. Commented Aug 21, 2014 at 5:30

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Python is all about combining many operations into one. In the script below, I iterate through feature classes in a workspace. For each, I iterate through a list of other feature classes to perform a near analysis on. I perform the near analysis, and with a little help of a dictionary as well as field calculate, I transfer the results into new fields. Finally, after performing the multiple near analyses I copy the feature class with feature class to feature class.

Try something like this:

import arcpy # Import arcpy module import os #features to which distance will be calculated RoadnearFeature_shp = r'C:\GIS route network\road.shp' TrainnearFeature_shp = r'C:\GIS route network\train.shp' restnearFeature_shp = r'C:\GIS route network\restaurant.shp' outLocation = r"C:\GISStuff" #Dictionary for field name assignment di = {} di [RoadnearFeature_shp] = "ROAD" di [TrainnearFeature_shp] = "TRAIN" di [restnearFeature_shp] = "REST" addedfields = [] # path where all my point shp files are kept arcpy.env.workspace = r'C:\ArcGIS sample data' # looping through all the files for file in arcpy.ListFeatureClasses (): for NearFC in [RoadnearFeature_shp, TrainnearFeature_shp, restnearFeature_shp]: #Perform analysis arcpy.Near_analysis(file, NearFC, "30 Meters", "LOCATION", "ANGLE") #Add fields to store near analysis results arcpy.AddField_management (file, di[NearFC] + "_ID", "LONG") arcpy.AddField_management (file, di[NearFC] + "_DIST", "DOUBLE") #Calculate fields arcpy.CalculateField_management (file, di[NearFC] + "_ID", "!NEAR_FID!", "PYTHON_9.3") arcpy.CalculateField_management (file, di[NearFC] + "_DIST", "!NEAR_DIST!", "PYTHON_9.3") #Delete fields from analysis arcpy.DeleteField_management (NearFC, "NEAR_FID") arcpy.DeleteField_management (NearFC, "NEAR_DIST") #Track fields that have been added addedfields.append (di[NearFC] + "_ID") addedfields.append (di[NearFC] + "_DIST") #Analysis done. Copy feature class filepath = os.path.join (r'C:\ArcGIS sample data', file) NewName = file[:-4] + "_Near.shp" arcpy.FeatureClassToFeatureClass_conversion (filepath, outLocation, NewName) #Optional #Delete analysis fields from original feature class for field in addedfields: arcpy.DeleteField_management (filepath, field)
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