Latest Contributions by RichardFairhurst

Here is the latest version....It is getting the job done but is still slow.   I am intrigued by rzufelt's suggestion of using the searchcursor, but if I understand correctly the searchcursor is read only so I am not sure how I can then work with the LAST_PNT field? I removed any print functions and it is still not much faster.   I will try a combining the 2 sort fields into one to see if that speeds it up. lastValue = arcpy.SearchCursor(infc, "", "", "", OID + " D").next().getValue(myField) #Get 1st row in cursor - gets last value based on OID  firstValue = arcpy.SearchCursor(infc, "", "", "", OID + " A").next().getValue(myField) #Get last row in cursor - gets first value based on OID Working Script import arcpy import os import types from arcpy import env #get Parameters from toolbox  #-For Use with Script Toolbox #inPts = arcpy.getparameterastext(0) #Animalfield=arcpy.getparameterastext(1) #SortField=arcpy.getparameterastext(2)  #-For Troubleshooting inPts = "C:\ArcGIS\Temp\Tester.shp" AnimalField = "AnimalNum" SortField = "MSTTime"   #Add Field print "Beginning:" arcpy.DeleteField_management(inPts,"LAST_PNT") arcpy.AddField_management(inPts,"LAST_PNT","SHORT",) ThesortString = AnimalField + " A; " + SortField + " D"  # Apply Sort rows = arcpy.UpdateCursor(inPts,"","","",ThesortString) print "Finished Sorting"  i=0 lastRow = "Starter"  for row in rows:     #print i     #i=i+1     if row.getValue(AnimalField) == lastRow:         #row.setValue("LAST_PNT",0)         lastRow=row.getValue(AnimalField)         rows.updateRow(row)              else:         row.setValue("LAST_PNT",1)         lastRow=row.getValue(AnimalField)         rows.updateRow(row)  del row del rows  print "Completed!" If speed is your concern, are your sort fields indexed?  Python may not take full advantage of them, but the Summary Statistics with a Join and Select where < MAX_MSTTime then field calculator then invert selection then field calculator would finish this is under 2 minutes for 20,000 records.  If you don't want a permanent output do the Summary Statistics to an in memory table. You are reinventing the wheel from my perspective, since the above workflow has been optimized (at least as of 10.1).  It will beat the performance of any sorted Python cursor easily, since those cursor are not optimized at all for using indexes in my experience. ... View more

OID values are not under a user's control and cannot be retained within an OID field of any exported feature class or table (it will always renumber).  Geoprocessing operations that output OID values for backward links (such as Intersect, Spatial Join, and many others) create a Long field with a name like TARGET_FID, JOIN_FID or FID_OPCODE (FID plus source name).  Once these fields are converted to a Long field they are no longer ensured to be unique in the output table.  These tools usually combine two inputs.  Copy Features does not retain OIDs in a field like this as you have seen. So you could create a polygon of your area and do a Spatial join with your features making the lines the TARGET_FID (primary source).  They would retain their original shape even if they were not contained completely by the area boundary.  Spatial Join should also work with all feature class type combinations (polygon on polygon, line or point, line on polygon, line or point, and point on polygon, line or point).  In effect Spatial Join is the process of Select by Location and output to a new feature class in one operation with backward OID support to your original source data. ... View more

Hi there, I am new to model builder and am stuck on what is a seemingly simple task.. I'd like the model to select the feature with the maximum value so that I can export and use it as my starting point for least cost path iterations. In my case, I just need the feature with the highest numerical value for Near_Dist to be selected. I have looked into the sort tool  (sort by descending then select first row), using code blocks and search cursors for calculate field or the select tool,  building expressions in select by attributes using somethine like: "Near_Dist=(SELECT MAX(Near_Dist) FROM TableName)" But I have been unsuccessful so I am resorting to this forum.  Please let me know if you have encountered this before / have any ideas on what I could do. Thanks so much in advance! Use Summary and create an output table with the Max value, Join it to the original feature class/table (create a layer or tableview first), and select where OBJECTID of the join table is not Null using Select By Attribute, then remove the Join.  This is the way I always do Statistical selections, although usually I am doing it using a group field unique value as the join field rather than the summary output itself as the join field.  And even more frequently I am doing this technique to use the join to transfer a statistical output back to the original table using the Field Calculator. If the join fails (because joins on double values is not always reliable and in which case you should not use =, but instead use >= to deal with imprecision) you could at least read the value in the output to a variable and then do a simple SQL expression directly on the original feature class: Near_Dist >= %value% - .0000001 ... View more