(addresses #72)
If the desired accuracy is to small, the naive weight computation can run
into an infinite loop, as floating point precision / rounding leads to
non-termination of the loop.
To partially address this, we move the accuracy check up, so that it
is also applied in the case of the 'naive' computation. This should make
it much less likely to run into this in practice.
For a full fix, we'd either need to check for non-progress in the loop
or do an analysis that the floating-point precision of double always
suffices for the remaining allowed input values.
Joachim Klein