topic Re: Having trouble mapping XY data in ArcMap in ArcMap Questions

Having trouble mapping XY data in ArcMap

NicholasSievers — Sun, 22 Nov 2020 01:43:46 GMT

Hi everyone,

This is my first ever post. I am having trouble mapping latitude and longitude coordinates in ArcMap. I am having trouble plotting XY coordinates in ArcMap 10.7. I imported points from a device called PocketLab. These are normal XY coordinates, but when I turned them into a feature class and tried to overlay them on the Oregon counties, they don't show up. I can confirm that the coordinate system and dataframe match for all my items.

Re: Having trouble mapping XY data in ArcMap

NicholasSievers — Sun, 22 Nov 2020 01:47:50 GMT

I can't view the photos for some reason, so here they are again.

Re: Having trouble mapping XY data in ArcMap

DanPatterson — Sun, 22 Nov 2020 02:54:21 GMT

I suspect that your long-lat points don't have a defined Geographic Coordinate System (perhaps GCS WGS84)

and your map of Oregon seems to be in a web mercator projected coordinate system. If your points don't have a defined coordinate system then they won't project-on-the-fly to that of the map.

data-management/define-projection

Re: Having trouble mapping XY data in ArcMap

Hussam_AlJabri — Sun, 22 Nov 2020 11:20:17 GMT

Hey NicholasSievers,

You need to change the coordinate system to a geographic coordinate system to present the Lat and Long.

Re: Having trouble mapping XY data in ArcMap

DanPatterson — Sun, 22 Nov 2020 13:31:08 GMT

guess you missed that in my post

I suspect that your long-lat points don't have a defined Geographic Coordinate System (perhaps GCS WGS84)

Re: Having trouble mapping XY data in ArcMap

curtvprice — Sun, 22 Nov 2020 21:26:01 GMT

This is a shortcoming in the ArcMap interface they fixed in Pro. Unfortunately when you try to add XY the interface by default assumes the coordinate system of your points is the same as the data frame (map). The fix (Step 8 in the KB article) is to change the coordinate system (in the dialog, not the data frame's [map's] coordinate system) to one that matches the XYs in the Table fields. Probably something like GCS WGS84 (a common default for GPS data).

Here is an Esri KB article that walks you through the process with lots of detail:

https://support.esri.com/en/technical-article/000018076

I also like to plug a friend of mine's book: Lining Up Data in ArcGIS. It's awesome.

Re: Having trouble mapping XY data in ArcMap

NicholasSievers — Sun, 22 Nov 2020 20:08:10 GMT

Thanks for the quick reply. I tried using the Project (data management) tool to reproject all of my items to WGS 1984 Geographic Coordinate System. This didn't end up changing anything. I also tried setting my data frame to the same coordinate system as my items.

Since I can only seem to change the coordinate system of the data frame itself through the properties menu, I ended up using ArcToolbox to fix the problem. Points are still not showing up over the oregon shapefile even though I can confirm they are all in the same coordinate system.

Re: Having trouble mapping XY data in ArcMap

DanPatterson — Sun, 22 Nov 2020 21:00:34 GMT

Have you tried to add the coordinates to the table to confirm them.

Add XY Coordinates (Data Management)—ArcMap | Documentation (arcgis.com)

Re: Having trouble mapping XY data in ArcMap

curtvprice — Sun, 22 Nov 2020 21:22:49 GMT

Nicholas,

Project will not solve your problem because the coordinate system was set wrong when you read in the points. You need to delete your points and start again. If you set the coordinate system in the Add XY dialog to match your XY coords in the table on the initial add xy to map , the points will plot on your map in the right place no matter what the data frame coordinate system is set to.

Please read the KB article I linked, it walks you through the process, step by step.

Re: Having trouble mapping XY data in ArcMap

DanPatterson — Sun, 22 Nov 2020 21:26:14 GMT

I should have added, when you calculate the coordinate system, don't specify an output coordinate system. You want them to be in the shape's coordinate geometry as noted in the link

The output POINT_X and POINT_Y field values are based on the coordinate system of the dataset, not the coordinate system of the map display.

You don't want to do this part

To force the POINT_X and POINT_Y values to be in a coordinate system different than the input dataset, set the Output Coordinate System environment.

Re: Having trouble mapping XY data in ArcMap

curtvprice — Sun, 22 Nov 2020 21:29:42 GMT

This is not Nicholas's problem, he has go back and do it again, and this time set the coord system to match the xy coordinate his table from the get go, as he creates point events (per KB I linked). (ArcGIS Pro is better at this, it looks at the table values and if it looks like geographic in the table, it auto-sets to GCS WGS84, not the map's CS.)

Re: Having trouble mapping XY data in ArcMap

DanPatterson — Sun, 22 Nov 2020 21:38:18 GMT

Based on what he said, I assumed he could tell whether the coordinates were in decimal degrees or in a projected coordinate system and defining them wrong wouldn't be an issue.

Perhaps doing it in ArcGIS Pro would be a better solution if ArcMap is still procedurally buggy

Re: Having trouble mapping XY data in ArcMap

NicholasSievers — Sun, 22 Nov 2020 22:26:32 GMT

I appreciate the help. I'll give this all a try. Might I add that my ArcMap has given me a ton of problems, both inside and outside of my Coursera GIS class. Bugs, bugs everywhere. This program is a giant industry standard headache sometimes, but very rewarding once it does what I want it to.

Sounds to me that I need to reconvert the excel files into .csv and then make sure that the shapefile I have is already in ArcMap beforehand, then turn the coordinates into XY data. Since I had originally plotted the XY data before adding anything else, they were given their own coordinate system (which can't be altered).

Re: Having trouble mapping XY data in ArcMap

curtvprice — Sun, 22 Nov 2020 22:35:22 GMT

Things should work fine from Excel. Just follow the step by step in the KB article and you should be fine.

You do not need a shapefile to plot points, they are "events" dynamically drawn from the table. You can then right click the event layer, save as shapefile or feature class once you have the points plotting on the map.

This is all detailed in the KB article.

Re: Having trouble mapping XY data in ArcMap

DanPatterson — Sun, 22 Nov 2020 22:40:24 GMT

While you are at it and if you are doing this in Pro.

If you have a csv - https://pro.arcgis.com/en/pro-app/tool-reference/data-management/xy-table-to-point.htm

or if you have an extremely clean excel file

Excel To Table (Conversion)—ArcGIS Pro | Documentation

and use a file geodatabase rather than a shapefile unless you need a shapefile for some other program.

Re: Having trouble mapping XY data in ArcMap

NicholasSievers — Sun, 29 Nov 2020 05:08:25 GMT

You both were very helpful, although what ended up happening was that I zoomed way out and discovered that the points were plotted, just on the inverse location of the map. This got me thinking that my latitude and longitude are backwards. Bingo! That was the problem!

Re: Having trouble mapping XY data in ArcMap

RichardDaniels — Thu, 06 May 2021 21:47:03 GMT

Steps are:

0. Open ArcMap, do not load an existing MXD.

1. add a table to ArcMap, this can be an Excel worksheet or .csv file. If using .csv ensure you have a header row.

2. look at your table in ArcMap, what are the x and y fields called? Look at the coordinates, are they longitude and latitude decimal degrees or something else like UTM?

3. Use Map an XY option on the table, use the field names identified in step 2 as input.

4. You will see your points on the map and a New Layer will be added to the map

you now have two options, define the projection for the Layer and Save to a .lyr file

5. right click on the layer and Export Data to Shapefile.

6. Use the Define Projection in ArcToolbox to set the projection.

Now when you load the shapefile or layer file into your 'other map' it will be reprojected on the fly to match your Map document.