ENH: GradientTable now calculates qvalues

Added an attribute to calculate the q-value table from the b-value one when big and small delta are given to the gradient table.
My policy is to comment when I see something that isn't PEP8. We're not
perfect, but we try...

On Fri, Nov 21, 2014 at 10:16 AM, Demian Wassermann <
notifications@github.com> wrote:

> In dipy/core/tests/test_gradients.py:
>
> > @@ -164,7 +164,21 @@ def test_deltas():
> >      npt.assert_equal(bt.big_delta, 5)
> >      npt.assert_equal(bt.small_delta, 2)
> >
> > +def test_qvalues():
> > +    sq2 = np.sqrt(2)/2.
> > +    bvals = 1500*np.ones(7)
>
> Yup, but PEP8 was not enforced at all on this file so I didn't know what's
> the project's policy on this
>
> —
> Reply to this email directly or view it on GitHub
> <https://github.com/nipy/dipy/pull/472/files#r20731123>.
>