Initial ages

[RomeshA]

Description

This PR uses rv_histogram to sample ages based on binned age data inputs. This resolves the current issue that initial ages are only integer values (or more specifically, the initial ages are only sampled from the lower bin edges).

Main:

This PR:

Larger bin widths now also work more correctly - with 10 year age bins e.g.

age,value
0,220.548
10,145.86
20,102.081
30,57.429
40,40.608
50,30.367
60,18.467
70,10.929
80,3.812
90,0.398
100,0.008
110,0

Main:

This PR:

Checklist

• Code commented & docstrings added
• New tests were needed and have been added
• A new version number was needed & changelog has been updated
• A new PyPI version needs to be released

[cliffckerr]

Looks good!

[cliffckerr]

Ah actually @RomeshA , I thought the docs build was failing idiopathically, but it's an actual error:

--> 107             dist = ss.Dist(rv_histogram((age_props,np.append(age_bins, age_bins[-1]+1)), density=age_props.sum() == 1), name='Age distribution')
    108         return dist

/software/anaconda3/lib/python3.11/site-packages/scipy/stats/_continuous_distns.py in ?(self, histogram, density, *args, **kwargs)
  10952                        "Specify `density` explicitly to silence this warning.")
  10953             warnings.warn(message, RuntimeWarning, stacklevel=2)
  10954             density = True
  10955         elif not density:
> 10956             self._hpdf = self._hpdf / self._hbin_widths
  10957 
  10958         self._hpdf = self._hpdf / float(np.sum(self._hpdf * self._hbin_widths))
  10959         self._hcdf = np.cumsum(self._hpdf * self._hbin_widths)

ValueError: operands could not be broadcast together with shapes (101,2) (101,) 

We should fix this before merging