Edits to shapefile fail to register on map

[WalterWitt]

Infuriating! I have an Arc map (Arc9.3.1) that shows the spatial distribution of observation points contained in a shapefile that was created from an xcel spreadsheet. Noticing an entry error for the co-ordinates of one point, I have changed the co-rods in the shape file using the Editor function in Arc. I have saved the edits and stopped editing but the point still plots in the original incorrect location in the map. I have checked the co-ordinates in the edited shapefile where the corrected co-ords are registered; I have cremoved the shapefile from the map and brought it in again. I have close Arc and reopened the map. The observation point still plots in the incorrect position, even though the new correct co-ordinates can be seen in the shapefile table. Can anyone help with this madness?

[DanPatterson_Retired]

Just to clarify, did you edit the coordinates in the shapefile's table? or did you get the shapefile into edit mode and move the shape to its new location (either manually, or by changing the coordinates of the point there.)

The reason that I ask, is that only field in a shapefile that is responsible for the locations is the Shape field.  Changes that you make to any other field are not reflected in the Shape field at all.  All other fields are there for convenience to show external attributes or have been calculated from the Shape field (like a point's x, y coordinates, a line's length or a polygon's area)

[WalterWitt · Accepted solution]

Dan

Thanks again for coming to the rescue. I have trouble following your answer.

For your first sentence: I used the Editor function in Arcmap to bring up the appropriate shapefile, making sure that the name of the shapefile was in the Target box of the Editor panel. With the Attribute Table for the shapefile open, I manually went into the MGA94E and MGA94N Fields and changed the co-ordinates in these fields to their correct values. I then Saved Edits and Stopped Editing. When I highlighted the observation point in question, it showed me that the position of the point on the map had not changed. Nor was there any point at the corrected coordinate location on the map.

I have used this approach to correct entries in shapefiles before with no problem, though I cannot guarantee that these changes involved co-ordinates. If I understand you to say that this approach is not appropriate for editing locations in shapefiles, could you please send me a link to something that explains the correct way to do it? Do I need to reimport the corrected xls file and recreate the shape file then?

Regards

Walter

[DanPatterson_Retired]

If memory serves Selecting features while editing—Help | ArcGIS for Desktop

and the editor toolbar needs to be used, so when you select the point you want to be in a new location

you can manually move it, and/or specify its coordinates from the popup

• The Edit tool allows you to interact with and modify the vertices of a feature and access a feature's geometry. In addition, the Edit Vertices pop-up toolbar appears when you are editing a feature's shape, allowing you to select, edit, add, and delete vertices.

You could of course, edit the spreadsheet, create a new event them, then export to shapefile.... but this is just as fast and it is easier on filename/state remembering.  Now... you should edit the table as well

[WalterWitt]

Dan

It seems a weird way of doing it but your suggestion did work, for which I thank you. I corrected the position of the errant data point by shifting its location in Edit mode. The co-ordinates I changed earlier are still at their corrected values, which now matches the location of the data point on the map.

No longer infuriated,

Thanks

Walter

[WalterWitt]

Thanks to all who helped out. Last time I did this, Dan asked me to sign off on the question to indicate it has finished. I can't find the way to do this using Actions but... case closed, thanks

[DanPatterson_Retired]

walter, you should see a 'mark correct' button beside the responses to the right, if one of them was the answer, you click it.  It isn't under actions, it is in the thread itself

[WalterWitt]

Done

Thanks again

Walter

[DanPatterson_Retired]

No problem Walter... but just to make sure... it was your response that was the correct answer... since it was that one you selected as the correct one