bug in core/halton.py

[BlazejGrabowski]

calling
pts = halton(4, 49, scramble=False)
produces a zero in pts[48,3] which is wrong

the correct value is 0.00291545

the problem occurs in the mod_matrix calculation when calling
np.floor(sum_matrix)
for the problematic entry, sum_matrix is 0.9999999999999999 and floor brings it down to 0, while it should result in 1

adding an epsilon at float precision to sum_matrix does the job, but I have not checked whether it can cause a problem at another place

version: pycalphad 0.10.1

[richardotis]

Hi Blazej, thanks for your report and analysis. Your solution should work fine without significant consequences. Would you like to submit a pull request with the fix?

[BlazejGrabowski]

Hi Richard, if you don't mind, I'd leave the fix to you
Thx for pycalphad, it's a fantastic tool, in particular for teaching

[richardotis]

Sure, I'll try to get to it soon.