class_docstr: A backend that stores the chain in an HDF5 file using h5py
  
  .. note:: You must install `h5py <http://www.h5py.org/>`_ to use this
      backend.
  
  Args:
      filename (str): The name of the HDF5 file where the chain will be
          saved.
      name (str; optional): The name of the group where the chain will
          be saved.
      read_only (bool; optional): If ``True``, the backend will throw a
          ``RuntimeError`` if the file is opened with write access.
class_docstr_tok: ["A","backend","that","stores","the","chain","in","an","HDF5","file","using","h5py","..","note",":",":","You","must","install","`","h5py","<","http",":","\/\/www.h5py.org\/",">","`","_","to","use","this","backend",".","Args",":","filename","(","str",")",":","The","name","of","the","HDF5","file","where","the","chain","will","be","saved",".","name","(","str",";","optional",")",":","The","name","of","the","group","where","the","chain","will","be","saved",".","read_only","(","bool",";","optional",")",":","If","``","True","``",",","the","backend","will","throw","a","``","RuntimeError","``","if","the","file","is","opened","with","write","access","."]
code: def __init__(
      self,
      filename,
      name="mcmc",
      read_only=False,
      dtype=None,
      compression=None,
      compression_opts=None,
  ):
      if h5py is None:
          raise ImportError(
              "you must install 'h5py' to use the HDFBackend"
          )
      self.filename = filename
      self.name = name
      self.read_only = read_only
      self.compression = compression
      self.compression_opts = compression_opts
      if dtype is None:
          self.dtype_set = False
          self.dtype = np.float64
      else:
          self.dtype_set = True
          self.dtype = dtype
  
imports: from __future__ import division, print_function
  import os
  from tempfile import NamedTemporaryFile
  import numpy
  from ..None import __version__
  from .backend import Backend
label_desc: Use image node_id 1 to create a new HDFBackend object from inherited base classes: Backend with example: obj = HDFBackend(filename, name, read_only, dtype, compression, compression_opts)