Add XY Data

[JeffPaar]

I'm new to ARCMap 10.1. I had the first training overview class, but am just getting my feet wet in editing.

I am taking some coordinates in an Excel file (or CSV) and attempting to pull them into a layer so I can see the points on my basemap. I create my layer, when I click File > Add Data > Add XY Data and then point to either my Excel or CSV file (containing the same structure), the X field and Y field in the "Add XY Data" dialog will not allow me to select my Lat/Long fields, which are in decimal format. It did allow this once, but then mapped the incorrect fields to the X/Y coordinates on my map, placing my coordinates across the entire world instead of in the tiny area in TN (please see attachment). I've looked for help on "Add XY Data" and it is there, but my system isn't following the rules.

What's the trick for adding the data? Ordering or naming the columns appropriately? Removing all but the data I want to have in my source?  Please advise me what to do - I'm stuck.

Thanks,
Jeff

[T__WayneWhitley]

I think you just parsed your fields for X and Y wrong, look again -- Latitude X and Latitude Y does not make sense; certainly it does not make sense to take part of the value and apply that in one direction and the other part in the opposite (X is longitude and Y is latitude in a Geographic Coordinate System).  Probably you simply overlooked that.  If you need help with the field calculations, that's easy too.  Post back here if that is also a problem.

[LucasDanzinger]

Usually if your desired field does not show up in display XY Data, it is coming in with the wrong data type- it needs to be a number in order to use and not a text string. What ArcMap does to enforce data types is scan the first 8 rows and determine if it should be a text string or a number (double). Something must be tripping it up. To check, add your data in, open the attribute table, right click the field header and select properties. What is the data type? If it is string, then something is likely causing ArcMap to read it as a string instead of a number. Go back into ArcMap and be sure that the first 8 rows have no characters that could make it show up as a text string. I'd also review this help article. It's really important that your field headers have no special characters or spaces as well. This can really mess with Excel tables.

[HardolphWasteneys]

Jeff,

your points are appearing at the geographic origin i.e. near 0 N, 0 W, in the Bight of Benin because you have not used the "edit" button in the add X-Y data tool to enter the geographic coordinate system of your data so when it gets plotted on the map, as shown, it is assumed by ArcMap that your coordinates are in Web Mercator Auxiliary Sphere which is measured in meters.  Hence your points are plotting a few meters north of the equator and west of Greenwich.  Had you started with some other basemap (say one that was in geographic coordinates) your data might have plotted correctly. 

Wayne and Lucas may also be correct about you data, that is a common problem.  I usually import the data from xls format into a geodatabase table to make sure it gets read as numeric and sometimes copy the data into new columns in the spreadsheet if the original read of the data caused it to be interpreted as text.

Hardolph

[AbelDean]

To add to what Hardolph said, be sure that you select just a geographic coordinate system (lat and lon) and not a projection. If you select a projection, the "Add XY data" function will assume that the coordinates are the linear grid coordinates of the projection, not the angular lat and lon.

I use "Add XY data" all the time, but I reverted to a copy of 10.0 instead 10.1. Someone at ESRI thought that "Add XY data" was too useful, so they decided to screw it up. Now in 10.1, it reads numeric values as text, or text values as numeric (even within quotation marks), it adds fields (with indecipherable numeric values) that take an existing field name and add a "_D" suffix for no discernible reason, and it sometimes makes some numeric fields completely <null>.