The LAS format, even binary, is not an exact representation.
The coordinates are encoded using and offset and a scaling, for each
coordinate.
In `write_LAS_with_properties()`, Simon has hard-coded:
```
LASheader header;
header.x_scale_factor = 1e-9 * (bbox.xmax() - bbox.xmin());
header.y_scale_factor = 1e-9 * (bbox.ymax() - bbox.ymin());
header.z_scale_factor = 1e-9 * (bbox.zmax() - bbox.zmin());
header.x_offset = bbox.xmin();
header.y_offset = bbox.ymin();
header.z_offset = bbox.zmin();
```
So, the approximate comparison of coordinates, for the I/O test,
should compare using about the same precision.
Laurent Rineau
3668ca16b2