def __init__(self, domain, coordinates='', names=None, calc_method=None):
r"""
Construct a chart on a real differentiable manifold.
TESTS::
sage: forget() # for doctests only
sage: M = Manifold(2, 'M')
sage: X.<x,y> = M.chart()
sage: X
Chart (M, (x, y))
sage: type(X)
<class 'sage.manifolds.differentiable.chart.RealDiffChart'>
sage: assumptions() # assumptions set in X._init_coordinates
[x is real, y is real]
sage: TestSuite(X).run()
"""
RealChart.__init__(self,
domain,
coordinates=coordinates,
names=names,
calc_method=calc_method)
# Construction of the coordinate frame associated to the chart:
self._frame = CoordFrame(self)
self._coframe = self._frame._coframe
def __init__(self, domain, coordinates='', names=None, calc_method=None):
r"""
Construct a chart.
TESTS::
sage: M = Manifold(2, 'M', field='complex')
sage: X.<x,y> = M.chart()
sage: X
Chart (M, (x, y))
sage: type(X)
<class 'sage.manifolds.differentiable.chart.DiffChart'>
sage: assumptions() # no assumptions on x,y set by X._init_coordinates
[]
sage: TestSuite(X).run()
"""
Chart.__init__(self,
domain,
coordinates=coordinates,
names=names,
calc_method=calc_method)
# Construction of the coordinate frame associated to the chart:
self._frame = CoordFrame(self)
self._coframe = self._frame._coframe
