topic Re: Two maps of Detroit on different sides of the globe in Coordinate Reference Systems Questions

Two maps of Detroit on different sides of the globe

AndreMasnari1 — Thu, 15 Jun 2017 22:36:15 GMT

Hello,
I'm a bit new to GIS and am having a bit of an issue
I have a .csv that i have converted into a feature class- the feature class displays correctly(it is a map of all robberies in Detroit in a given year).
I also have a .shp that is all of the locations of the lights in the same city- it also displays correctly, but in a completely different part of the map.
When I add a basemap, the .shp points are all in the correct city, while the .csv created feature class is out in the Atlantic ocean.
I have ensured that all the layers and the data frame are using the same geo reference systems.

I'm at a bit of a loss here.

I've attached both the .shp in a zip and the .csv I'm working with. Any help would be much appreciated.

Re: Two maps of Detroit on different sides of the globe

DanPatterson_Retired — Thu, 15 Jun 2017 22:41:50 GMT

without even looking... if it is in North America, the longitudes need to be negative

Re: Two maps of Detroit on different sides of the globe

AndreMasnari1 — Thu, 15 Jun 2017 22:44:19 GMT

Yes, they are negative

Re: Two maps of Detroit on different sides of the globe

DanPatterson_Retired — Thu, 15 Jun 2017 22:49:37 GMT

The csv doesn't have a defined coordinate system then and you haven't mixed up longitude (X) and latitude (Y) have you?... copy a few lines and paste to save the whole download and unzip thing.

Re: Two maps of Detroit on different sides of the globe

JoshuaSchwartz — Thu, 15 Jun 2017 22:52:00 GMT

Here's what I see when I follow the workflow below:

Here was my workflow:

Open ArcMap
Add .csv to TOC
Right-click on .csv and select "Disply XY Data"
Select WGS84 as the Geographic Coordinate system, and ensure X = Longitude field and Y = Latitude field
1. Results = robberies.csv Events appears in TOC, with points plotted in correct locations.
Add OriginalOHLights to TOC
1. Results = OHLights points appear in correct location

His longitudes are negatives, BTW.

Re: Two maps of Detroit on different sides of the globe

DanPatterson_Retired — Thu, 15 Jun 2017 23:03:43 GMT

then the X,Ys could have been swapped... if the negative is missing for longitudes you end up north of the equator but on the wrong side of Greenwich.. If they are swapped, you end up in the southern hemisphere

Re: Two maps of Detroit on different sides of the globe

JoshuaSchwartz — Thu, 15 Jun 2017 23:06:14 GMT

Yes sir. He says he's new to GIS, could very much be the case of swapped Xs and Ys.

Re: Two maps of Detroit on different sides of the globe

AndreMasnari1 — Thu, 15 Jun 2017 23:14:03 GMT

I followed that exact workflow, only to end up with a the map zooming somewhere in the area of greenland

Re: Two maps of Detroit on different sides of the globe

AndreMasnari1 — Thu, 15 Jun 2017 23:36:39 GMT

Nevermind, I am a dork and messed something up. In any case, it works now. Issue seems to be I had a projection of world_auxilary_sphere 1984 chosen.
Thanks for the help!

Re: Two maps of Detroit on different sides of the globe

JoshuaSchwartz — Fri, 16 Jun 2017 15:44:08 GMT

ArcMap will always set the dataframe's projection to the first dataset's projection that you add to the TOC. I suspect you had the World Map basemap in your TOC prior to doing anything else, which would explain the world_auxiliary_sphere 1984.

Re: Two maps of Detroit on different sides of the globe

AndreMasnari1 — Thu, 22 Jun 2017 17:38:51 GMT

Sigh....

So, using the exact same data set, but simply a different .csv(burglary instead of robbery), I am having the same issue. Following the exact same workflow as listed.... How could this be?

Re: Two maps of Detroit on different sides of the globe

DanPatterson_Retired — Thu, 22 Jun 2017 20:04:39 GMT

A few lines of the csv and what column you assigned as the X and the Y would be useful.

Also, the csv will not have a defined coordinate system unless you used the Define Projection tool in arctoolbox, to tell it what it is.

Don't try to load csv files into a dataframe with existing data until you have converted it to a feature layer or shapefile, and define its projection/coordinate system.

If the data are in the range -180 to 180 and -90 to 90, then you undoubtedly have a file with a geographic coordinate system... perhaps GCS WGS84

Details would help

Re: Two maps of Detroit on different sides of the globe

AndreMasnari1 — Thu, 22 Jun 2017 22:05:25 GMT

A few lines pasted below....
X and Y are Long and Lat

cartodb_id	the_geom	rownum	caseid	crimeid	crno	address	category	offensedescription	stateoffensefileclass	incidentdate	hour	sca	precinct	council	neighborhood	censustract	lon	lat
272	0101000020E610000001DE02098AC354C03108AC1C5A344540	518041	1479122	1795714	1.2E+09	00 CARPENTER / JUSTINE	ROBBERY	ROBBERY - STREET - OTHER WEAPON	12000	1/21/2012	21	1111	11	City Council District 3	CITY AIRPORT	5106	-83.0553	42.409
645	0101000020E61000007CF2B0506BCA54C03108AC1C5A244540	529922	1486042	1804326	1.2E+09	02200 SCHAEFER	ROBBERY	ROBBERY - STREET - STRONG ARM	12000	2/20/2012	20	411	4		OAKWOOD HEIGHTS	5245	-83.1628	42.284
997	0101000020E61000009487855AD3CC54C0AAF1D24D62384540	544040	1499920	1821681	1.2E+09	20100 GREENFIELD	ROBBERY	ROBBERY - STREET - STRONG ARM	12000	3/25/2012	0	804	8	City Council District 2	GREENFIELD	5401	-83.2004	42.4405

Re: Two maps of Detroit on different sides of the globe

DanPatterson_Retired — Thu, 22 Jun 2017 22:27:43 GMT

So you are using Make XY Event Layer I presume... You have the option of specifying the Spatial Reference, so in the absence of other information I would assume a GCS WGS84 aka unprojected data in long lat with a wgs84 datum.

That should load into any file. If you get the X and Y's mixed up, then you will have issues.

Now... check for any rows that don't have the correct Long/lat coordinates. If there are any blank cells in that column, then you are going to have issues... dump any rows that aren't complete before trying to import the data