Hi,

I need to create a grid in a file geodatabase. The coordinates of the grid need to be 15 decimal places.

So say I create a grid with the lower left coordinate set to 73.000000000000000, 28.000000000000000, when I click off the feature an then reselect it, the coordinate has changed to 73.000000000000057, 28.000000000000057.

Can anyone tell me why this happens?

Thanks

Paul

Fifteen decimal places isn't physically possible with an 8-byte IEEE floating-point value (aka "double precision"). The most you can get is 15 total digits (two left and thirteen right).

What you really need to do is locate where this ridiculous requirement is being generated. Fifteen places in meters is 1 femtometer (inside the atomic nucleus, and at least a hundred billion times more precise than can be captured by a geographic sensor; not even gamma-ray crystallography needs that kind of resolution). Fifteen places in angular degrees is roughly equivalent to tenths of nanometers (Angstroms, which are used to measure the distance between atoms in molecules -- only ten million times more precise than any geodata can be accurate).

Esri has an entire whitepaper devoted to how coordinate references operate -- Understanding Coordinate Management in the Geodatabase. I think you'll find that anything more than 7 places in geodata is a waste of computing resources.

- V