Add X,Y data not plotting points

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08-11-2017 09:14 PM
DianaGrill
New Contributor II

Hi,

I am using ArcGIS 10.3.  I have a .csv table containing latitudes and longitudes derived from google maps.  I am attempting to Add X,Y data to my map.  My longitude in the X field, my latitude in the Y field.  The point feature is added to my table of contents but no points appear on the map.  I used the default projections WGS1984, the same as the data frame.  Does anyone have an idea why this won't plot. I attempted to import the table as excel, then as .csv.  The latitude and longitude

Thank you

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4 Replies
DanPatterson_Retired
MVP Esteemed Contributor

Show a row or two. 

  1. the coordinates need to be in decimal degrees
  2. longitude is negative in the western hemisphere, latitude is negative in the southern hemisphere
  3. don't mix up longitude and latitude
  4. the file if it is a csv needs a comma between the numbers
  5. if you use a comma as a decimal separator (ie -75,5) then fix it or make sure your regionalization is set properly
  6. no  blank rows
  7. and the most important step.... add it to a brand new empty data frame without any other data in it to ensure that everything is correct before you bring it into one with data

sample for near Ottawa Canada

Longitude, Latitude

-75.5, 45.5

-75.01234, 45.55555

DianaGrill
New Contributor II

Thank you so much for your answer.  I figured out the problem after much consternation. 

1. There were values that were missing a latitude and longitude so the researcher put in 999, which is an impossible long, latitude.  As the longitude should be between -180 to 180 and latitude should be between -90 to 90. 

2. I changed the datum that I brought in the table in on to NAD83.  For some reason that data points don't show when I bring them in as WGS84.  The data frame is in WGS84

I needed the two things to be changed though as just bringing the table in as NAD83 didn't initially work.

Do you know why bringing it is as WGS84 doesn't work?  I read online that google maps uses WGS84 as its datum, and that is what the researcher used to obtain the coordinates.

Lines of coordinates in British Columbia  :

LatitudeLongitude
49.11005-122.846
49.11009-122.851

Also, thank you for the great list of steps.  I am going to keep that for later reference as this is only the second time I've performed this function and last time I got it to work after much fidgeting, but am not sure how I did it. 

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DanPatterson_Retired
MVP Esteemed Contributor

the difference between NAD83 and WGS84 in BC isn't going to be much of an issue, so if that works stick with it, assuming it isn't survey grade positioning (ie, if you can see if from there... close enough)

The researcher should separate out the data into two batches if there is no coordinates to prevent this from happening again...

JayantaPoddar
MVP Esteemed Contributor

Adding to Dan's valuable suggestions and your finding of the value "999", also ensure that there is no space in the cells containing the Lat./Lon. values.

Considering that you have removed the rows containing the value "999", just add the CSV file to ArcMap. Open the table. Check the field properties of Lat./Lon. fields. If the Datatype of the field is "Text", there is a probability that it has a space in one or more values of the field.

Let us know your observation.

In ArcMap (Field Calculator; Python Parser), you can delete these spaces (at start and end of string) by using .strip() funtion. Once that is done, you could Convert a string field to a number field 



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