Duplicated decimal coordinate values?

[ERIASGroup]

Hello. I hope someone can help me with what appears to be an odd problem.

In ArcMap Desktop v10.5.1 I have calculated EN coordinates for a set of sample points for field work. However, I noticed that the coordinate values all have the same decimal values regardless of where they are located. The points are not located in a line so how can they have the same decimal values? For example, two completely separate point locations some 60 metres apart have the following values: P1 is E 315722.4077 / N 5809888.1804, P2 is E 315767.4077 / N 5809843.1804. 

Please see attached image.

ALL the points have these same repeated decimal values. The field type is Double and precision is set to 6 decimal places. The data frame is correct with all project data in GDA_1994_MGA_Zone_55.

The same points calculated using DMS have unique values and are NOT duplicated at the seconds (") level. Hmmm

Thanks for any help or tips in advance!

Grant

[EricCollinsOVV]

My question back to you regards significance - does it matter? Are you truly measuring to the micrometer (assuming metric coordinates)?

I would guess all the coordinates are relative to your first point and are equidistant integer separations.

If your first point had decimals and everything else is arrayed in exact intervals (eg 10x10 and multiples therof) they all would exhibit the exact same decimal in the coordinate display.

Eg 315752.4077 + 10m east = 315762.4077

Want to make your life simple? Shift your workspace 0.4077 m west and 0.1804 m south.

[DanPatterson_Retired]

I suspect it is floating point representation when a coordinate system isn't used/defined during the creation of the file... I have seen this too many times.  Shifting it will likely produce more errors since the coordinates aren't high precision to begin with

[EricCollinsOVV]

Respectfully disagree. Every point is relative to the first point created. Every relative point is arrayed and based on an integer grid.

If the first point exhibits floating point coordinates, all all other points will naturally have the same decimals.

It is not a coordinate system problem. If the author had set their first point on an integer coordinate, all other points would have decimals of 0 as well.

Again, the real question to the author is - does it matter?

[DanPatterson_Retired]

well your tests must differ from mine...but yes, waiting for the OP will solve the mystery

[XanderBakker]

In case the points are generated based on for instance the center points of the polygons, it would be good to have a look at the coordinates of the polygons, to see if they explain the repeating decimal values (would be logical IMHO).