class_docstr: A proposal using differential evolution.
  
  This `Differential evolution proposal
  <http://www.stat.columbia.edu/~gelman/stuff_for_blog/cajo.pdf>`_ is
  implemented following `Nelson et al. (2013)
  <https://doi.org/10.1088/0067-0049/210/1/11>`_.
  
  Args:
      sigma (float): The standard deviation of the Gaussian used to stretch
          the proposal vector.
      gamma0 (Optional[float]): The mean stretch factor for the proposal
          vector. By default, it is :math:`2.38 / \sqrt{2\,\mathrm{ndim}}`
          as recommended by the two references.
code: def __init__(self, sigma=1.0e-5, gamma0=None, **kwargs):
      self.sigma = sigma
      self.gamma0 = gamma0
      super().__init__(**kwargs)
  
file_path: emcee/src/emcee/moves/de.py
imports: from functools import lru_cache
  import numpy
  from .red_blue import RedBlueMove
label_desc: Use image node_id 1 to create a new DEMove object from inherited base classes: RedBlueMove with example: obj = DEMove(sigma, gamma0)