Editing Vertices

[JoshuaBroxson]

Confession: I don't know much about ArcMap 10, I've been dropped into a role where I use it to make maps for our company, but I have very little training or experience with it.

Up until yesterday when I needed to smooth out a polygon, I would select the layer to edit, select the polygon in question, select the Edit Vertices function, and then go to work adding vertices and making changes.

Today, when I go through the same process, the changes won't stick. I'll add some vertices here and there, move things around a little, but when I finish the sketch, some changes stay and others disappear. If I make large adjustments, everything proceeds as per usual. If I make fine adjustments, they disappear and I'm left with the same mess with which I began.

I've perused the forums looking for an answer, and while I've found questions which seem to be the same or at least relate to my own query, I can't make sense of the answers or make them work for me.  I've played with the snapping tolerance, but it doesn't seem to matter what I set it at, the problem persists.

I can't remember adjusting anything, or changing any settings.  I'm the only person who uses this workstation, so I don't think anyone else has changed anything. Just one day it worked one way, the next day it works another.

Please help.

Thanks,

Josh

[JoshuaBroxson]

Update.

I've been playing with it some more and I don't know if this will clarify or confound.

This time I was just creating a polygon, not editing one.  If I create two points within a couple of centimeters (on my screen; it doesn't matter if I'm at 1:100 or 1:500,000) of each other the first point will disappear.  If they are farther apart, say 5cm, the shape behaves normally. So I can make a 5cm x 5cm square, but if I were to try and make a 2cm x 2cm square, it goes nuts.

[JakeSkinner · Accepted solution]

What is your XY tolerance for the feature class you are editing?  You can check by right-clicking on the feature class in the catalog window > Properties > Tolerance.  You will want to make sure that you are not entering a distance smaller than what the tolerance is set to. 

The XY tolerance is the minimum distance between coordinates before they are considered equal.  See the following link:

http://resources.arcgis.com/en/help/main/10.1/index.html#//003n00000005000000

[JoshuaBroxson]

Thank you! That explanation makes a lot of sence; however, I'm not seeing Tolerance listed in the properties. I've got General, XY Coordinate System, Fields, and Indexes. None of them have an option for Tolerance. I'm using ArcMap 10. I'm not sure what other information would be useful.

[JakeSkinner]

Hi Joshua,

Looks like you are working with a shapefile.  Convert this to a feature class by performing the following steps:

1.  Right-click on a folder > New > File Geodatabase
2.  Right-click on the File Geodatabse > Import > Feature Class (single)
3.  Browse to the shapefile as the input and specify a name

Add the feature class to ArcMap and see if you can create a point within a couple centimeters from another.

[JoshuaBroxson]

That did it.  Thank you so much!