Latest Contributions by RichardFairhurst

Probably your feature class tolerance and resolution are too low with a shapefile to ensure that points near a boundary do not duplicate.  A File geodatabase allows for double precision and I believe there may be tools to convert to high precision.  In a sense it is correct to duplicate an incident on a boundary.  Also, if your boundaries have overlaps, even very small overlaps, they can cause a problem.  Sloppy topology on your polygons could cause several problems.  Intersecting the polygons with themselves would show you if your topology is sloppy.  Making sure your topology is clean is crucial if you want very precise results. If there really is polygon overlap or points fall on the boundary, then the other program is also skewing your results by making a random choice on which boundary to assign the count to without consulting you.  I prefer the ARCGIS behavior so that I could process a secondary routine to find points that need to have their count cut in half to split the incident between to two or more areas manually (or shift its position so that it is clearly assigned to a single polygon). ... View more

I'm trying to use the Calculate Field tool to calculate the 3D Length of an interpolated line and I can't seem to figure out the correct syntax for the expression. I've tried !shape.3Dlength@miles!, !shape.length3D@miles!, !shape.3D_length@miles!, and !shape.3D length@miles! but I keep getting an error. Any thoughts? I think 3D length is not supported using the field calculator (at least not this syntax).  The only listed defined keywords for the shape components are:  type, extent, centroid, firstPoint, lastPoint, area, length, isMultipart, and partCount. I believe you are limited to using the LENGTH_3D option of the Add Z Information tool.  Then you would have to apply a unit conversion from your base units to miles. No guarantee this will work, but since the 3D Analyst tool uses the term LENGTH_3D as the keyword and I don't see that variant listed above, you could try: !shape.length_3D@miles! ... View more

I am using the testing data in a file deodatabase. It is not a geometric network. The features are about 2000 to flip at one time. I use code exactly like this. Is the fc open in a  map?  Have you tried editing manually?  Are you sure you have access to the workspace you used?  Post your method of getting the fc into your code. ... View more

It should be noted that this request is not simply to use multiple category fields in a layer (which is supported with the "Unique values, many fields" option), but to use multiple fields within predefined symbol Styles.  Support for this feature would requre additional options for the Sytle Manager editor as well so that the multi-field symbol styles could be developed and edited in the first place. ... View more

I am trying to flip selected pipelines using stand-alone python window. Below are the steps I used:    1). line join attributes from other tables (MakeFeatureLayer, AddJoin);    2). select lines based on the joined attributes (SelectLayerByAttribute);    3). remove joins (RemoveJoin);    4). flip line on the selected lines (FlipLine_edit with or without MakeFeatureLayer after the selection). It is shown the same error: ERROR 999999: Error executing function. Workspace or data source is read only. Workspace or data source is read only. Failed to execute (FlipLine). Anyone has any solution? Thanks. Can you post your actual script?  What is the line data source?  Is it SDE?  Is it a geometric network?  What license level do you have?  How many features are you trying to flip at one time?  I found it crashes if I try to flip too many at one time (more than about 10,000).  Did you use code like this for the flipline section? import arcpy try:     arcpy.FlipLine_edit(inFeatures) except Exception, e:     # If an error occurred, print line number and error message     import traceback, sys     tb = sys.exc_info()[2]     print "Line %i" % tb.tb_lineno     print e.message ... View more

For Python use: len(!FieldName!) Brackets is only for VB Script. ... View more

Thanks Rich for your extreme intelligence on the matter, like I said they serve different purposes.  It seems that Riverside County Trans employees have lots of free time on their hands.  Thanks for your service. Well this tools happens to be the workhorse tool of all of my scripts, so getting to know it well has proven very beneficial for creating scripts that give the free time to help others.  😉 ... View more

I see Summarize as more oriented towards ArcView Users while Frequency is more oriented towards ArcInfo users. You should reexamine the abilities of the Summary Statistics tool before you dismiss it as only oriented to the needs of mere ArcView/Basic users. 1.  Frequency requires you to select at least one case field and although it allows you to select multiple case fields you are limited to selecting them in the order that they occur within the data source.  This means that when you select multiple fields that the sort order of the multiple unique combined case field values is restricted to the field arrangement of the original source. Summary Statistics allows you to select no case field, one case field, or multiple case fields.  When you use multiple case fields they can be arranged in any order that you like.  Therefore the sort order of the multiple unique combined case field values can be in any arrangement that you like and is free from any restrictions of the source data field arrangement order, 2.  Frequency does not require you to include a summary value, but if you do you can only output the Sum of numeric fields.  The summed fields must be arranged in the order that they appear in the source data. With Summary Statistics you are required to create at least one summary field, but it can produce any form of summary value you want (Sum, Min, Max, Mean, Range, Standard Deviation, Count, First and Last).  It can summarize numeric fields and text fields (Min, Max, Count, First, Last being the most useful text summaries).  The order of the summary fields can be outputted in any arrangement that you like and you can get multiple different types of summary values on any given source field. Although date fields are filtered out of the Summary fields drop down, you can actually still type them into the Summary Fields text Box and press enter to add them to the summary field list.  After they are added to the summary field list you can choose any of the summary options that are available for numbers.  The output of date summaries will be the numeric representations of the date (Min, Max, First, Last) or calculations based on the date (all other summaries).   If you use the Field Calculator to transfer a Min, Max, First or Last date number into an actual date field the date number will be transformed back to its native date appearance. Given all of the abilities of the Summary Statistics tool, I see no reason to ever use the Frequency tool again. ... View more

Another cool sample that does a unique, but not necessarily a summarize is from the following help doc.  This is nice because you don't have to output a table, you can see a unique list on screen, so in the end the frequency is better and more related to your question, but there is an output file.  Sometimes a unique handles what you need, plus this is just a cool sample. http://resources.arcgis.com/en/help/main/10.2/index.html#//018w00000011000000 import arcpy fc = "c:/data/base.gdb/well" field = "Diameter" # Use SearchCursor with list comprehension to return a#  unique set of values in the specified field# values = [row[0] for row in arcpy.da.SearchCursor(fc, (field))] uniqueValues = set(values) print(uniqueValues) or uniqueValues = sorted(set(values)) print(uniqueValues) I did not recommend Frequency, because it requires an Advanced license while Summary Statistics is available with a Basic license, and in my opinion Summary Statistics can do everything Frequency can do and more.  If the Summary Statistics/Frequency tool is used in Model Builder or a python script and you can script the response to duplicate values without user interaction you do not have to output a file if you output it to an in_memory table ... View more

Hi, I'm having an issue with using the new da cursors in Arc 10.1. I have a basic script that uses selected features ("watpoints") and copies them to an abandoned layer (watabdev) arcpy.MakeFeatureLayer_management(point,"watpoints") with arcpy.da.InsertCursor(watabdev,("SUBTYPE","SHAPE@XY")) as cur:                  with arcpy.da.SearchCursor("watpoints",["SHAPE@XY"]) as cursor:                      for row in cursor:             cur.insertRow((1,row[0])) del cur, row, cursor I used with cursors and tried deleting the cursors afterwords. But after I run the tool, arcmap gives me an error that the abandoned layer is in a closed state and I cannot access it. Any suggestions? Thanks. According to the help: "The advantage of using a With statement is that it will guarantee close and release of database locks and reset iteration regardless of whether the cursor completed successfully or an exception occurred." That would imply the del statements are not needed.  Have you tried the script without them? ... View more

working on a sewer project and assigning new names to about 1500 manholes. Is there a way to check my data to see if there are duplicate names that I have assigned? If so, can you point me in the right direction? Thanks Use Summary Statistics on the field and look for any frequency greater than 1.  Relate or join back to the source to select them. ... View more

Adding layers only automatically occurs while you are working directly in the Desktop environment, which includes the Python Window.  In script tools you explicitly have to add layers to a map.  Look at arcpy.mapping.AddLayer, arcpy.mapping.InsertLayer, and arcpy.mapping.Layer to deal with the map TOC.  Once the TOC is handled the zoom function should work.  If you are just selecting one point you may want to look at panToExtent.  Assuming you have a Layer called lyr with a selection this will pan the dataframe: df.panToExtent(lyr.getSelectedExtent()) Edit: MakeFeatureLayer_management is only for the geoprocessor and converts a feature class on disk to a layer in memory that the geoprocessor can use.  Models and scripts use this tool frequently to make feature class outputs into layers so that other geoprocesses that only accept layer inputs will work.  It is not used to alter maps, otherwise almost every model would alter your maps. ... View more

Assuming you are working with Geodatabase annotation and are not constantly changing your map extent, you should build a cache to improve speed.  Look into the Feature Cache toolbar. ... View more

Yes, that was it. I created a File Geodatabase and now it only takes 5 minutes to conduct the join and create the shapefile. That is great !! Thank you very much for all your help ! That is a lot more like it.  So now you see why I use File Geodatabases almost exclusively. ... View more