How do I get scipy.stats.truncnorm.rvs to use numpy.random.default

I am having trouble with random_state in scipy.stats.truncnorm. Here is my code:

from scipy.stats import truncnorm
from numpy.random import default_rng
rg = default_rng( 12345 )
truncnorm.rvs(0.0,1.0,size=10, random_state=rg)

I get the following error:

  File "test2.py", line 4, in <module>
    truncnorm.rvs(0.0,1.0,size=10, random_state=rg)
  File "/opt/anaconda3/envs/newbase/lib/python3.8/site-packages/scipy/stats/_distn_infrastructure.py", line 1004, in rvs
    vals = self._rvs(*args, size=size, random_state=random_state)
  File "/opt/anaconda3/envs/newbase/lib/python3.8/site-packages/scipy/stats/_continuous_distns.py", line 7641, in _rvs
    out = self._rvs_scalar(a.item(), b.item(), size, random_state=random_state)
  File "/opt/anaconda3/envs/newbase/lib/python3.8/site-packages/scipy/stats/_continuous_distns.py", line 7697, in _rvs_scalar
    U = random_state.random_sample(N)
AttributeError: 'numpy.random._generator.Generator' object has no attribute 'random_sample'

I am using numpy 1.19.1 and scipy 1.5.0. The problem does not occur with scipy.norm.rvs.

CodePudding user response：

In scipy 1.7.1, the problem line has been changed to:

def _rvs_scalar(self, a, b, numsamples=None, random_state=None):
    if not numsamples:
        numsamples = 1

    # prepare sampling of rvs
    size1d = tuple(np.atleast_1d(numsamples))
    N = np.prod(size1d)  # number of rvs needed, reshape upon return
    # Calculate some rvs
    U = random_state.uniform(low=0, high=1, size=N)
    x = self._ppf(U, a, b)
    rvs = np.reshape(x, size1d)
    return rvs

Both have uniform, but rg does not have random_sample:

In [221]: rg.uniform
Out[221]: <function Generator.uniform>
In [222]: np.random.uniform
Out[222]: <function RandomState.uniform>

np.random.random_sample has this note:

.. note::
    New code should use the ``random`` method of a ``default_rng()``
    instance instead; please see the :ref:`random-quick-start`.