more nan filtering before fitting

[Nick Amin]

np.random.seed(42)
h1 = Hist1D.from_random("poisson", params=[2], bins="50,0,20", size=100)
h2 = Hist1D.from_random("poisson", params=[2], bins="50,0,20", size=100)
(h1/h2).fit("a*x+b")

gives

ValueError                                Traceback (most recent call last)
<ipython-input-88-c730772a78c7> in <module>
      2 h1 = Hist1D.from_random("poisson", params=[2], bins="50,0,20", size=100)
      3 h2 = Hist1D.from_random("poisson", params=[2], bins="50,0,20", size=100)
----> 4 (h1/h2).fit("a*x+b")
      5 # h = h1.divide(h2)
      6 # h.plot(show_errors=True)

~/sandbox/dev/yahist/yahist/hist1d.py in fit(self, func, **kwargs)
   1089 
   1090     def fit(self, func, **kwargs):
-> 1091         return fit_hist(func, self, **kwargs)
   1092 
   1093     fit.__doc__ = fit_hist.__doc__

~/sandbox/dev/yahist/yahist/utils.py in fit_hist(func, hist, nsamples, ax, draw, color, legend, label, band_style, likelihood, curve_fit_kwargs)
    314         absolute_sigma=True,
    315         likelihood=likelihood,
--> 316         **curve_fit_kwargs,
    317     )
    318 

~/sandbox/dev/yahist/yahist/utils.py in curve_fit_wrapper(func, xdata, ydata, sigma, absolute_sigma, likelihood, **kwargs)
    193         sigma=sigma[~tomask],
    194         absolute_sigma=absolute_sigma,
--> 195         **kwargs,
    196     )
    197     if likelihood:

~/Library/Python/3.7/lib/python/site-packages/scipy/optimize/minpack.py in curve_fit(f, xdata, ydata, p0, sigma, absolute_sigma, check_finite, bounds, method, jac, **kwargs)
    732     # NaNs cannot be handled
    733     if check_finite:
--> 734         ydata = np.asarray_chkfinite(ydata, float)
    735     else:
    736         ydata = np.asarray(ydata, float)

~/Library/Python/3.7/lib/python/site-packages/numpy/lib/function_base.py in asarray_chkfinite(a, dtype, order)
    484     if a.dtype.char in typecodes['AllFloat'] and not np.isfinite(a).all():
    485         raise ValueError(
--> 486             "array must not contain infs or NaNs")
    487     return a
    488 

ValueError: array must not contain infs or NaNs

Need to do some more NaN filtering before fitting?

[Nick Amin]

fixed by 05b456a