[Fix] Round points instead of flooring

[lucas-diedrich]

LMD xml files should only contain integer values.

py-LMD maps floats to integers via np.floor. Especially if all coordinates are relatively small and for smalll numerical imprecisions, this can lead to numbers that are very far off from the original number.

Discussed with @sophiamaedler

Example

This PR implements strategy 3

func1 = lambda xi: int(np.floor(xi)) # current strategy 
func2 = int # python integer 
func3 = lambda xi: int(round(xi, 0)) # rounding 

# example coordinates
# note the -1e-14 which is practically 0
x = [-1, -0.9, -0.5, -0.1, -1e-14, 0, 0.1, 0.5, 0.9, 1, 1.1, 1.5]

# func1: [-1, -1, -1, -1, 0, 0, 0, 0, 1, 1, 1] # -1e-14 rounded to -1
# func2:  [-1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1] # -0.9 rounded 0
# func3: [-1, -1, 0, 0, 0, 0, 0, 1, 1, 1, 2] # reasonable rounding results

Rounding + integer gives the closest values to the actual coordinates

[mschwoer]

ROFL

[mschwoer]

do we know why it was floor in the first place :-)

[mschwoer]

note sure if this is a breaking change: API etc all stays the same, only internal precision changes ..