Latest Contributions by RichardFairhurst

I am trying to flip lines in a geometric network to match the flow direction and can't seem to find a tool to do this.  I tried installing the Water Utility Network Editing for ArcGIS 10.2. I followed the directions to install and when I open the toolbar most of the tools show as "Missing". Are there any other ways to get this accomplished without the Water Utility Network Editing Add-In? Thanks! If you have at least a Standard (ArcEditor) license you can use the Flip Line tool under the Editor toolbox to flip all of the lines at once.  This tool directly alters the original features without creating a copy, and it will not flip direction-dependent attributes, only line geometry. Therefore, you should first either create a copy of the entire feature class before flipping the lines or after you have selected the lines you intend to flip, export that set of features to a new feature class.  Then you  can use the Flip Line tool to alter the geometry followed by a Join to the copied features and using the Field Calculator to flip any direction-dependent attributes.  If you have no unique ID field to export to do a standard join you could use the Spatial Join tool to get the matching Target ObjectID field values of your original lines needed to perform the join. ... View more

Jake, the script works with the feature class you provided, using the Python window within ArcMap. Yes, but it only worked because you selected one feature.  If you select 2 features you will get nothing.  That is why you have to use the IN operator to work with a list of 0 or more items. OBJECTID = 12345; 12346 is an invalid selection statement (not sure how Python resolves the list into the SQL statement, but = cannot be used with a list). OBJECTID IN (12345, 12346) is valid and will return both records. OBJECTID IN (12345; 12346) Returns nothing since a semicolon is invalid in an SQL list. ... View more

The result is the same whether I use dsc.fidSet, dsc.FidSet, or dsc.FIDSet. Are you positive your layer has a feature selection already applied?  If nothing is selected, no FID values should be returned. ... View more

The feature class has over a million records.  Printing that many records will take quite a while. The arcpy.AddMessage("Continue") value was returned. If there are a million FID values placed within the IN clause I don't know that there won't be an error.  Try it on a much smaller set first.  I suspect the cursor won't accept a string that big that it could pass to the query parser and performance would be horrible. If it is going to process the entire table don't include a where clause.  If it is a selection based on some grouped attribute values include those fields in the field list and write a logical SQL expression that gets the selection.  If you are doing it based on a spatial query and get a huge list, perhaps try feeding portions of the OID list in a for loop to the query expression if an error gets thrown or performance drops too drastically. ... View more

How many features do you have in your target feature class? If you print out the fidset, are all of these features included in the semicolon-delimited string? Can you post the results of printing the fidset from your dsc object? If the fidset is delimited with semicolons it will have to be changed so that the fid values are delimited by commas for the where clause SQL to work.  The SQL IN operator only works with lists of values separated by commas.  Nothing in SQL works with semicolon separated lists. ... View more

import arcpy mxd = arcpy.mapping.MapDocument ("CURRENT") df = arcpy.mapping.ListDataFrames (mxd)[0] lyr = arcpy.mapping.ListLayers(mxd, "Lot_Lines", df)[0] for lyr in arcpy.mapping.ListLayers(mxd): tlyr = lyr dsc = arcpy.Describe(tlyr) sel_set = dsc.fidSet if dsc.shapeType == "Polyline":   rows = arcpy.da.SearchCursor(tlyr, "OBJECTID = " + sel_set)   for row in rows:    arcLength = row.ARCLENGTH    shapeLength = row.Shape_Length   if arcLength > 0:    print arcLength   else:    print shapeLength   del row   del rows The error is in line 32, for row in rows: RuntimeError: An invalid SQL statement was used.  I know the select Object ID works, because it changes values depending on the feature selected. When you switched back to the original cursor type you got no records because your where clause needs to use the IN operator not the = operator. The error using the new arcpy.da cursor is due to the cursor declaration syntax being different.  With the arcpy data access (arcpy.da) cursor you have to supply a mandatory field name list prior to defining an optional where clause.  Your code has no field list.  At a minimum the field list would have to include OBJECTID, ARCLENGTH and Shape_Length.  So this code:   rows = arcpy.da.SearchCursor(tlyr, "OBJECTID = " + sel_set) should be changed to this code:   rows = arcpy.da.SearchCursor(tlyr, ["OID@", "ARCLENGTH", "SHAPE@LENGTH"], "OBJECTID IN (" + sel_set +")") OID@ makes sure you get the correct ObjectID field name reference, regardless of the database.  Possibly SHAPE@LENGTH should be Shape_Length, depending on whether you want to access a geodatabase length field or the actual shape geometry length.  You also do not have to use field names again after getting the cursor.  You can use numbers to represent the fields.  So that means the code beyond that line could also change to:   rows = arcpy.da.SearchCursor(tlyr, ["OID@", "ARCLENGTH", "SHAPE@LENGTH"], "OBJECTID IN (" + sel_set + ")")   for row in rows:    arcLength = row.[1]    shapeLength = row.[2]   if arcLength > 0:    print arcLength   else:    print shapeLength   del row   del row ... View more

I am using a Personal Geodatabase and i am not able to make out how i can return more than one value as of now, in the query. request help to modify my existing query in such a way that it suits where_clause of SelectLayerbyAttributes. As a beginner in arcobjects I honestly do not know what Summary statistics is. Regards, Pavan Summary Statistics is a geoprocessing tool, not ArcObjects per se, although it can be accessed through ArcObjects.  Since it is a personal geodatabase, build the query in Access and look at the sql of the subqueries.  If you can make it work there it should translate to the query.  At least that is how I would approach it. ... View more

ok, I never use model builder but went ahead on your recommendation and here's how it looks after export! arcpy.CalculateField_management('bm_parcels_calc', "bm_parcels_calc.PARCEL_KEY", "!myDB.\"myNT\\myUsername\".%parcel.parcel_key!", "PYTHON_9.3", "") "!myDB.\"myNT\\myUsername\".%parcel.parcel_key!" seriously!!!  I wouldn't have guessed! I would never have guessed either.  Anyway, at least now you know it can work with a Join and the Field Calculator.  Your code is almost certainly faster, especially since it appears to update 5 fields in one pass, where Field Calculator only can update 1 field in a pass and would have to be run 5 times to do the same. ... View more

A similar post was left unanswered http://forums.arcgis.com/threads/29621-Selection-QUERY-duplicits?highlight=GROUP+BY  , I had tried to do a workaround as mentioned in the link by using  WHERE .. IN ( Select .. GROUP BY .. HAVING ..) but the problem I need to perform GROUP BY on multiple fields and need to Select Longitude and Latitude in Subquery, hence i cannot use "WHERE Longitude, Latitude IN" as you can use only one field while using IN. Request any kind of help. Regards, Pavan Unless you use a Personal Geodatabase (Access) or an SDE database like SQL Server or Oracle, GROUP BY can only return one value and cannot be correlated to any other fields in a table (I.e., the max is for every record in the entire table).  A file geodatabase or shapefile do not support the subquery syntax you want to use.  For those types of databases you must use the Summary Statistics tool and a join to do the selection based on the joined grouped summary values.  A multi-field join would have to use the Make Query Table tool. Generally I breakdown and concatenate the multiple fields and use the Summary Statistics to do the selection or data transfer through a standard join. ... View more

I am rewriting the last set of calculations again.  I found that I need to do too many replace updates with the table names as I do each direction and side (and even subarea for my large County).  Even the field names need to be replaced sometimes if I do not do the process exactly the same each time.  So I am making it easier to edit the input fields and increasing the readability of the calculations: From House Numbers Min_Meas = [CL_ENDS_LINES.MIN_MEAS] Asc_Desc = [ADDRESS_ODD_RIGHT_Full.ASC_DESC] Min_Min_Meas = [ADDRESS_ODD_RIGHT_Full.MIN_MIN_MEAS] Max_Max_Meas = [ADDRESS_ODD_RIGHT_Full.MAX_MAX_MEAS] House_Interval = [ADDRESS_ODD_RIGHT_Full.HOUSE_INTERVAL] Min_From_House_Number = [ADDRESS_ODD_RIGHT_Full.MIN_FROM_HOUSE_NUMBER] Max_To_House_Number = [ADDRESS_ODD_RIGHT_Full.MAX_TO_HOUSE_NUMBER] Max_From_House_Number = [ADDRESS_ODD_RIGHT_Full.MAX_FROM_HOUSE_NUMBER] Min_To_House_Number = [ADDRESS_ODD_RIGHT_Full.MIN_TO_HOUSE_NUMBER] If Asc_Desc = "Ascending" AND Min_Meas < Min_Min_Meas Then   Raw = (Min_Meas - Min_Min_Meas) / House_Interval + Min_From_House_Number   Output = Round((Min_Meas - Min_Min_Meas) / House_Interval/2, 0) * 2 + Min_From_House_Number   If Output < Raw Then Output = Output + 2 ElseIf Asc_Desc = "Ascending" AND Min_Meas > Max_Max_Meas Then   Raw = (Min_Meas - Max_Max_Meas) / House_Interval + Max_To_House_Number   Output = Round((Min_Meas - Max_Max_Meas) / House_Interval/2, 0) * 2 + Max_To_House_Number   If Output < Raw Then Output = Output + 2 ElseIf Asc_Desc = "Descending" AND Min_Meas < Min_Min_Meas Then   Raw = (Min_Meas - Min_Min_Meas) / House_Interval + Max_From_House_Number   Output = Round((Min_Meas - Min_Min_Meas) / House_Interval/2, 0) * 2 + Max_From_House_Number   If Output > Raw Then Output = Output - 2 ElseIf Asc_Desc = "Descending" AND Min_Meas > Max_Max_Meas Then   Raw = (Min_Meas - Max_Max_Meas) / House_Interval + Min_To_House_Number   Output = Round((Min_Meas - Max_Max_Meas) / House_Interval/2, 0) * 2 + Min_To_House_Number   If Output > Raw Then Output = Output - 2 Else   Output = "" End If To House Numbers Max_Meas = [CL_ENDS_LINES.MAX_MEAS] Asc_Desc = [ADDRESS_ODD_RIGHT_Full.ASC_DESC] Min_Min_Meas = [ADDRESS_ODD_RIGHT_Full.MIN_MIN_MEAS] Max_Max_Meas = [ADDRESS_ODD_RIGHT_Full.MAX_MAX_MEAS] House_Interval = [ADDRESS_ODD_RIGHT_Full.HOUSE_IINTERVAL] Min_From_House_Number = [ADDRESS_ODD_RIGHT_Full.MIN_FROM_HOUSE_NUMBER] Max_To_House_Number = [ADDRESS_ODD_RIGHT_Full.MAX_TO_HOUSE_NUMBER] Max_From_House_Number = [ADDRESS_ODD_RIGHT_Full.MAX_FROM_HOUSE_NUMBER] Min_To_House_Number = [ADDRESS_ODD_RIGHT_Full.MIN_TO_HOUSE_NUMBER] If Asc_Desc = "Ascending" AND Max_Meas < Min_Min_Meas Then   Raw = (Max_Meas - Min_Min_Meas) / House_Interval + Min_From_House_Number   Output = Round((Max_Meas - Min_Min_Meas) / House_Interval/2, 0) * 2 + Min_From_House_Number   If Output > Raw Then Output = Output - 2 ElseIf Asc_Desc = "Ascending" AND Max_Meas > Max_Max_Meas Then   Raw = (Max_Meas - Max_Max_Meas) / House_Interval + Max_To_House_Number   Output = Round((Max_Meas - Max_Max_Meas) / House_Interval/2, 0) * 2 + Max_To_House_Number   If Output > Raw Then Output = Output - 2 ElseIf Asc_Desc = "Descending" AND Max_Meas < Min_Min_Meas Then   Raw = (Max_Meas - Min_Min_Meas) / House_Interval + Max_From_House_Number   Output = Round((Max_Meas - Min_Min_Meas) / House_Interval/2, 0) * 2 + Max_From_House_Number   If Output < Raw Then Output = Output + 2 ElseIf Asc_Desc = "Descending" AND Max_Meas > Max_Max_Meas Then   Raw = (Max_Meas - Max_Max_Meas) / House_Interval + Min_To_House_Number   Output = Round((Max_Meas - Max_Max_Meas) / House_Interval/2, 0) * 2 + Min_To_House_Number   If Output < Raw Then Output = Output + 2 Else   Output = "" End If ... View more

While you are welcome to solve your problem without using a join and the field calculator, you are flat out wrong that Python does not calculate across inner joins.  I do it in practically every model I build and it works if I converted the Join and calculation from Model Builder to Python script.  You needed to build it using Model Builder with the query parser and then export it to Python before declaring that it cannot be done.  Here is an example that works every week for me: # Process: Calculate First_STNAME Field... arcpy.CalculateField_management(RDNUMBER_Routes_Layer, "RDNUMBER_Routes.First_STNAME", "[RDNUMBERS_ALL.FIRST_STNAME]", "VB", "") So based on this example (which I had not looked up previously and could not test before) I can now point out what you needed to do to make your original code work. You had: arcpy.CalculateField_management('calcLyr',"PARCEL_KEY", 'parcelTv.parcel_key') which had several errors.  You had not included the feature class qualifier for the field to be calculated, you had not enclosed the calculation expression with field delimiters and you had not specified the Parser.  So correcting your code to work, here is how the syntax should have been for a VB calculation (faster than Python with joins at 10.0): arcpy.CalculateField_management('calcLyr', "bm_parcels_calc.PARCEL_KEY", "[parcelTv.parcel_key]", "VB", "") or for a Python calculation: arcpy.CalculateField_management('calcLyr', "bm_parcels_calc.PARCEL_KEY", "!parcelTv.parcel_key!", "PYTHON_9.3", "") I also agree that the code you came up with is faster, especially as more fields are compared or transferred.  I have used that code technique recently to fill in Null values for 34 fields in a table prior to making those fields not accept Null values in a new feature class and it is definitely faster.  I just don't want misinformation about what can or cannot be done with Python using joins and the field calculator to go uncorrected. ... View more

I am assuming your data is based on just a Geographic Coordinate System and only uses decimal degrees for its coordinate values.  If so, I believe you can only use angular units to work with that data.  You would need to use the Project tool to convert it to a Projected Coordinate System that uses linear units such as meters and that is designed to project area correctly.  Once you have chosen a good projection use the Project tool to transform your data into a new feature class you can buffer with linear units such as meters. Melita Kennedy is the resident ESRI projection expert on the forum.  Here is some advice she has given others on the subject of choosing an equal areas projection: "You'll want to use an equal-area projection. You'll find some for the US under projected coordinate systems, continental, north america like "USA Contiguous Albers Equal Area Conic USGS". You could modify it and change the central meridian and standard parallels into your area of interest, but I'm not sure the census data is accurate enough to warrant that. When we've done testing of various equal area projections, the density of the data (how many vertices) had a greater effect that which equal area projection was used." ... View more

Why doesn't this work?!  I'm going nuts!     addrTbl = r'Database Connections\Connection to blah.sde\blah.dbo.addr'     parcelTbl = r'Database Connections\Connection to blah.sde\blah.dbo.parcel'     arcpy.MakeTableView_management(parcelTbl, 'parcelTv')     arcpy.MakeFeatureLayer_management('default.gdb\\bm_parcels_calc', 'calcLyr')         arcpy.AddJoin_management('calcLyr', "PARCEL_PIN", 'parcelTv',"parcel_id","KEEP_ALL")         # works to here.         arcpy.CalculateField_management('calcLyr',"PARCEL_KEY", 'parcelTv.parcel_key') Show me how to fix it and I'll buy you lunch at next years UC! I believe you forgot to qualify the calclyr PARCEL_KEY field with the underlying feature class name, especially since both the fc and table have the PARCEL_KEY field. So I believe it should be (double check the single/double quotes also):     arcpy.CalculateField_management('calcLyr','bm_parcels_calc.PARCEL_KEY', 'parcelTv.parcel_key') ... View more