Latest Contributions by KimOllivier

‎08-24-2014

Too late! There is already a NEW, open, existing, working standard format endorsed by OGC called a GeoPackage! This uses Spatialite which is Sqlite3 with a simple spatial extension. I predict it will sweep the use of shapefiles away within a few years. It has all the benefits of a shapefile, editable in place, spatial indexing, projections. Haven't heard of Sqlite? It is the most popular database in the word that is already built into the operating system of every phone (Apple, Android, Nokia) and is well supported. It is already built into Python 2.6+ Spatialite is already supported in all the open GIS packages and it is even there in ArcGIS at 10.2! Not fully supported for editing yet, but it will be. Start now by searching for spatialite in the help document. Spatialite will be used as a capable geodatabase on mobile devices. Have a look at sqlite. It is very fast, compact, SQL compliant and comes in a single file. Note it is a single user database, but that makes it much simpler. A web server application is only one user.

‎08-24-2014

Too late! There is already a NEW, open, existing, working standard format endorsed by OGC called a GeoPackage! This uses Spatialite which is Sqlite3 with a simple spatial extension. I predict it will sweep the use of shapefiles away within a few years. It has all the benefits of a shapefile, editable in place, spatial indexing, projections. Haven't heard of Sqlite? It is the most popular database in the word that is already built into the operating system of every phone (Apple, Android, Nokia) and is well supported. It is already built into Python 2.6+ Spatialite is already supported in all the open GIS packages and it is even there in ArcGIS at 10.2! Not fully supported for editing yet, but it will be. Start now by searching for spatialite in the help document. Spatialite will be used as a capable geodatabase on mobile devices. Have a look at sqlite. It is very fast, compact, SQL compliant and comes in a single file. Note it is a single user database, but that makes it much simpler. A web server application is only one user.

‎08-22-2014

Not really the question, but I can't delete the answer in this new forum! You can build in database relates to relate features, don't use shape files any more! It is possible to have temporary map relates held in the MXD too.

‎08-22-2014

In the help there is a suggested folder structure for a project. If you put your master MXD file at the top, ArcMap will recognise that as the 'Home' directory so that you can keep help, data and tools below the home with relative paths. When you open the MXD the tools and databases will be at the top of the catalog tree. There is no built-in project file that keeps track of everything like some other packages unfortunately. Even the scripts have to find relative paths with extra code. This is partly because Windows does not recognise the useful relative path notation that is in Unix. You can make the data paths relative with an option in ArcMap if the data is below the MXD. Geoprocessing packages attempt to bundle up data and tools into a single package for passing around. Which only works for samples or trivial amounts of data. I zip up the whole folder and send it off to be unpacked manually. If I am strict with my code it can work in another location without changing the code or data paths.

‎08-22-2014

I avoid escape characters by using triple quotes. It is so much easier and more legible. Except when it is the first character when it is a bit hard to see.

‎08-13-2014

You do verify expressions in a Python script before you run them. I thought the main use for the calculator was in ModelBuilder. But even there you could improve in it by making a custom tool with better error handling.

‎08-13-2014

Use a Python cursor. You then have complete control over every calculation, you can test for null values, errortrap, report errors, continue after an error and generally make a robust calculation. Since Field Calculator simply wraps a cursor around your expression it is just as slow as a cursor, which with the new arcpy.da module is fast enough to be useful. You could wrap the cursor in a tool to prevent a lot of repetitive typing.

‎08-13-2014

I have a table that I want to make into a featureclass by adding a shape field and then populating the values. This is not supported so I looked for alternatives. They are all very clumsy. It comes about because I have a many to many relation so a simple join will not do. I want the first point from one featureclass to populate many rows in the table so that I end up with a featureclass with some coincident points. Suggestion 1: In CreateFeatureClass() there is a <template> option. This will do.... oh no it won't! Why not? We already have to define a shape type and the spatial reference template at the end of the options is required for the spatial reference. So why cannot we just use a table as a template without a shape field? Suggestion 2: Simply allow AddField to add a shape field with suitable spatial reference. Then I don't have to painfully copy the table row by row into a dummy featureclass using a Python cursor. This is tricky to set up a field list, strip off the objectid field carefully and loop about. Suggestion 3: Just use FME and abandon ArcGIS. Because this is available as a workaround nothing will change I fear. Once I have the ( null) shape field it would be easy to populate it from a dictionary of XY values obtained from another featureclass. Another complex workaround which could handle a many to one would be to use a Querylayer but both tables have to be in the same geodatabase so that would be another copy of another table. I am ending up with a slow complex Python script that could be a simple one-liner.

‎08-13-2014

I have a table that I want to make into a featureclass by adding a shape field and then populating the values. This is not supported so I looked for alternatives. They are all very clumsy. It comes about because I have a many to many relation so a simple join will not do. I want the first point from one featureclass to populate many rows in the table so that I end up with a featureclass with some coincident points. Suggestion 1: In CreateFeatureClass() there is a <template> option. This will do.... oh no it won't! Why not? We already have to define a shape type and the spatial reference template at the end of the options is required for the spatial reference. So why cannot we just use a table as a template without a shape field? Suggestion 2: Simply allow AddField to add a shape field with suitable spatial reference. Then I don't have to painfully copy the table row by row into a dummy featureclass using a Python cursor. This is tricky to set up a field list, strip off the objectid field carefully and loop about. Suggestion 3: Just use FME and abandon ArcGIS. Because this is available as a workaround nothing will change I fear. Once I have the ( null) shape field it would be easy to populate it from a dictionary of XY values obtained from another featureclass. Another complex workaround which could handle a many to one would be to use a Querylayer but both tables have to be in the same geodatabase so that would be another copy of another table. I am ending up with a slow complex Python script that could be a simple one-liner.

‎06-26-2014

Too hard in Python? Compared to C# or .NET? You must not have tried to use ArcObjects! This is a much steeper learning curve, but I agree that .NET or C# has better tools for building an interactive form. If you are not familiar with either but your coder is familiar with C# then let him/her go for it. I am only familiar with Python and Arcpy and this is a python forum. You can now use AddIns with ArcPy and Python (instead of .Net) that allows you to build a tool that works on the cursor message queue that can pick a point and interactively build a rectangle for example. The sample in the help draws a grid by dragging a box on the screen. All in Python. The main deficiency in creating interactive tools with Python is the lack of an integrated dialog builder other than the inital dialog. It is possible to use Tkinter but it puts up a separate window outside the ArcMap instance. I wonder if this will be improved in 10.3 or ArcGIS Pro? Note that there will be no AddIns in ArcGIS Pro, so that option will be closed.

‎06-25-2014

Is it so hard to just build a new locator? I save the results into a script and then add a delete in front. Then I just recreate from scratch. It only takes a few minutes. I find that very small changes sabotage a rebuild such as renaming the locator version.

‎06-25-2014

I managed this problem by dissolving all the roads into single streets and added the min and max, odd and even calculated for the whole street to make a second fallback locator that would have all the gaps covered by the range. It might be a bit more approximate but you do get a match. You could also have some defaults based on the length of the street and the average house frontage width. If you wanted to refine it, you could create a route system, calibrate with the existing address ranges and then use the measures to predict the start and ends on each segment to repopulate the original segments.

‎06-11-2014

Since writing my solution I have found an ArcView 3.x solution that shows I have not covered all the cases. You could have a line running through a pair of vertices on a polygon with rentrant sides that extent out each way to the polygon boundary between vertices. I assumed that the longest line would always be coincident with vertices at the ends. http://www.jennessent.com/arcview/longest_lines.htm Well done to Jeff Jenness for handling this case in Avenue.

‎06-10-2014

It is really annoying to have text fields 255 chars wide containing 10 chars which result from loading in spreadsheets or CSV files etc. I have written a scanner in awk that counts the maximum width of the contents of each field so you can round them up and resize the fields. The obvious way is to use FME (or the Data Interoperability Extension) to reprocess the inputs to standardise the field widths. You can also reorder the fields easily. You can set the field widths in a SCHEMA.INI (see Microsoft help) before you load text files. If the sources are shapefiles then it is possible to copy the file using Conversion/FeatureclassToFeatureclass with a Field Mapping to redefine the output field widths. This is harder to program. Note that in really wide fields you can change the height of the rows in the table and the contents will wrap! I only just discovered this after 10 years of using tables. The trouble with formatting tables is that its all manual settings and does not persist when you close the table.

‎06-10-2014

To save you writing a lot of scripts have a look at the ET Tools third party scripts. They have extensive tools to clean up dangling lines. ET_GeoWizards. There are some new snapping tools at 10.2 in the Editing Tools that do not use the Coverage Tools, but you still need a Standard licence.

Online Status	Offline
Date Last Visited	2 weeks ago

My Ideas

Latest Contributions by KimOllivier

Re: introduce a zipped shapefile format (SHZ)

Re: introduce a zipped shapefile format (SHZ)

Re: Project possible? - select feature and show data from connected ones in a form

Re: Project possible? - select feature and show data from connected ones in a form

Re: How to handle spaces and special characters in arcpy.Select_analysis?

Re: Improving Field Calculation Error Message

Re: Improving Field Calculation Error Message

AddField should be able to add a shape field to a table

AddField should be able to add a shape field to a table

Re: Create polygon from click

Re: 10.1 - Cannot Rebuild a Address Locator with Alternate Name Table

Re: Matching closest house number with dual-range street data

Re: Longest Line Within a Polygon

Re: Resizing the width of fields.

Re: C# Program/Python Script

Re: ArcGIS Pro Tips & Tricks 2026 – Share Yours!

Re: Difference between feature iteration and Row i...

Re: Adding WFS to webmap using Python API

Re: ArcGIS 3.6.2 Pro Not Closing

Re: ArcGIS for Personal use new licensing from 202...