Truncate radian floats in data files.

Truncate radian floats in data files.

* weather.py(correlate): The radian values in data files have a tendency
to vary by the tiniest rounding errors from one Python release to
another. By truncating them to the 7th decimal place, which is still
sub-meter resolution, this problem is minimized and the resulting data
diffs become far less noisy.