> wouldn't using "%.9f" suffice and force always showing a set number of digits?

Note that the code was changed from ``%.4f`` to ``%s``. 

The tradeoff with ``%s`` (or ``%f``) is that the output is uglier, but we get max precision; the tradeoff of ``%.9f`` (or related) is that we lost some precision (usually in insignificant digits probably) but it's prettier. 

I do not have strong feelings either way. @jrrideout, you make the call.