class_docstr: Class for MGH format header
  
  The header also consists of the footer data which MGH places after the data
  chunk.
class_docstr_tok: ["Class","for","MGH","format","header","The","header","also","consists","of","the","footer","data","which","MGH","places","after","the","data","chunk","."]
docstr: If goodRASFlag is 0, set the default affine
docstr_tok: ["If","goodRASFlag","is","0",",","set","the","default","affine"]
code: def _set_affine_default(self):
      """If goodRASFlag is 0, set the default affine"""
      self._structarr["goodRASFlag"] = 1
      self._structarr["delta"] = 1
      self._structarr["Mdc"] = [[-1, 0, 0], [0, 0, 1], [0, -1, 0]]
      self._structarr["Pxyz_c"] = 0
  
imports: from os.path import splitext
  import numpy
  from ..affines import from_matvec, voxel_sizes
  from ..arrayproxy import ArrayProxy, reshape_dataobj
  from ..batteryrunners import BatteryRunner, Report
  from ..filebasedimages import SerializableImage
  from ..fileholders import FileHolder
  from ..filename_parser import _stringify_path
  from ..openers import ImageOpener
  from ..spatialimages import HeaderDataError, SpatialHeader, SpatialImage
  from ..volumeutils import Recoder, array_from_file, array_to_file, endian_codes
  from ..wrapstruct import LabeledWrapStruct
label_desc: Use image node_id 25 for calling the MGHHeader obj's underlying member method code with example usage: obj._set_affine_default() without return types