topic Re: Calculating fields - add start and end coordinates of line features to table in Geoprocessing Questions

Calculating fields - add start and end coordinates of line features to table

AlexanderPichlmayr — Tue, 16 Apr 2013 08:41:55 GMT

Hello everybody,

Since a wile I am serching a way to solve a problem but cant get to any result.
What I want to do is to add koordinates of the startpoint and endpoint of a line-feature to its attribute table.
In my project I have to traw a great number of lines (representing power grid) so I manually added 4 fields (StartX, StartY, EndX, EndY). Is there any toold in arc toolbox that can help me calculate the koordinates for those 4 fields. Manually adding the data would be very time consuming. For better understanding i attached a photo with a sample of the grid (green line) and its attribute table.

Thanks for any kind of help
Alex

Re: Calculating fields - add start and end coordinates of line features to table

JoeBorgione — Tue, 16 Apr 2013 11:26:49 GMT

Right click on one of the field headings and select calculate geometry. You'll be presented with a a pull down to select what you want to calculate.

Re: Calculating fields - add start and end coordinates of line features to table

AlexanderPichlmayr — Thu, 18 Apr 2013 07:21:39 GMT

Very good thanks a lot. That helps calculating the start and endpoint of a line-feature. Is there also a way to generate coordinates of vertex points?

Re: Calculating fields - add start and end coordinates of line features to table

JoeBorgione — Thu, 18 Apr 2013 10:08:03 GMT

Very good thanks a lot. That helps calculating the start and endpoint of a line-feature. Is there also a way to generate coordinates of vertex points?

Found this with a google search (with apologies to bing users...)

Re: Calculating fields - add start and end coordinates of line features to table

AlexanderPichlmayr — Tue, 23 Apr 2013 05:55:48 GMT

Hey thanks for the link. I tryed it already but it seems the tool does not work on arggis 10. (tool is from 2006). When I use it it shows up with the error " no module named win32api found failed to execute". I have Python 2.6(.5) installed and tryed with downloeading the extentions already -> no improvement! Dont really know what elese I can try!?

Re: Calculating fields - add start and end coordinates of line features to table

RobertPotter — Wed, 15 May 2013 23:43:20 GMT

Hi,

I have a similar problem but I need to put the calculation of the coordinates (start and end of a line) into a model or script so it can be run on a regular basis.

Any clues?

Re: Calculating fields - add start and end coordinates of line features to table

RichardFairhurst — Wed, 15 May 2013 23:46:23 GMT

Hi,

I have a similar problem but I need to put the calculation of the coordinates (start and end of a line) into a model or script so it can be run on a regular basis.

Any clues?

It has to be done as a Python9_3 Field Calculation (at least at 10.0 and up) connected to a layer created with the Make Layer tool (not a feature class stored on disk, which is the normal output of most tools). It is a simple calculation:

!Shape.FirstPoint.X! - does the Start/From end X coordinate
!Shape.FirstPoint.Y! - does the Start/From end Y coordinate
!Shape.LastPoint.X! - does the End/To end X coordinate
!Shape.LastPoint.Y! - does the End/To end Y coordinate

M and Z can be substituted for X or Y above, and Centroid can be used instead of FirstPoint/LastPoint to get the midpoint of the line. http://resources.arcgis.com/en/help/main/10.1/index.html#//00170000004m000000

Re: Calculating fields - add start and end coordinates of line features to table

RobertPotter — Thu, 16 May 2013 01:25:31 GMT

Thanks but it didn't work, well it did for a while then I got this after nearly 3 minutes

Start_X !Shape.FirstPoint.X! PYTHON_9.3 #
Start Time: Thu May 16 12:00:07 2013
ERROR 000539: Error running expression: GPVARIANTOBJECT0.FirstPoint.X
Traceback (most recent call last):
File "<expression>", line 1, in <module>
SystemError: error return without exception set

The index was either too large or too small.
Failed to execute (Calculate Field).
Failed at Thu May 16 12:02:50 2013 (Elapsed Time: 2 minutes 43

What does it mean? Essentially what you told me was correct and it worked a bit then stopped!!

It did 1970 of the 2843 in the file

[ATTACH=CONFIG]24353[/ATTACH]

Re: Calculating fields - add start and end coordinates of line features to table

RobertPotter — Thu, 16 May 2013 02:00:35 GMT

Ah overall thank you!

The problem above I have found out is on the client end (ie. my machine) basically it just ran out of memory. I have now freed some memory and it works fine.

Thanks

Re: Calculating fields - add start and end coordinates of line features to table

RobertPotter — Thu, 16 May 2013 02:27:31 GMT

Oh well as would be the case I spoke too soon. Initially, it did finish but when I actually reviewed the results It had only calculated the coordinates for the first 1970 records (Start_X, Start_Y, End_X, End_Y) ????
So to check that result I tried to redo it but this time ArcMap CRASHED!!! It asked if I wanted to send an error report to ESRI and I said yes, why not?

Then comes the funny bit....

...then would you believe it that Crashed also!!!
[ATTACH=CONFIG]24354[/ATTACH]

So really it is back to my original question ... how do I do this?????

Re: Calculating fields - add start and end coordinates of line features to table

RichardFairhurst — Thu, 16 May 2013 02:56:31 GMT

Oh well as would be the case I spoke too soon. Initially, it did finish but when I actually reviewed the results It had only calculated the coordinates for the first 1970 records (Start_X, Start_Y, End_X, End_Y) ????
So to check that result I tried to redo it but this time ArcMap CRASHED!!! It asked if I wanted to send an error report to ESRI and I said yes, why not?

Then comes the funny bit....

...then would you believe it that Crashed also!!!
[ATTACH=CONFIG]24354[/ATTACH]

So really it is back to my original question ... how do I do this?????

You have a corrupted point. Probably it has no coordinate and is an empty shape. That will fail.

Select everything that did not calculate, sort it on the objectID. First try panning to the first record. If it does not move the location, you have a corrupted point. These points get created when you do not actually set the geometry of a point, but instead start entering attributes before the point ever got set (which will insert a record with empty geometry). The same can happen with lines and polygons that have only attributes, but no geometry. But lines and polygons are easier to find, because they always have lengths or perimeters of 0 length (points show no automatically created measurements to tell you that they are corrupt).

If that is the case, deselect that first point. Now try the calculation on the rest of that selection set. If that works, you have confirmed that you have a corrupted point. In any case there is no need to recalculate the points you already got coordinates assigned to for the X coordinate.

Check geometry might also detect any corrupted points if it fails a second time.