def S(self, val: float) -> None:
"""Set the spot price of the underlying."""
if not is_pos(val):
raise ValueError(
f'Expected non-negative float, instead got {val} with type '
f'{type(val)}!')
self._S = float(val)
def K(self, val: float) -> None:
"""Set the strike price."""
if not is_pos(val):
raise ValueError(
f'Expected non-negative float, instead got {val} with type '
f'{type(val)}!')
self._K = float(val)
def div(self, val: float) -> None:
"""Set the time to maturity."""
if not is_pos(val):
raise ValueError(
f'Expected non-negative float, instead got {val} with type '
f'{type(val)}!')
self._div = float(val)
def pd(self, val: float) -> None:
"""Set the risk free probability of down move."""
if not is_pos(val):
raise ValueError(
f'Expected non-negative float, instead got {val} with type '
f'{type(val)}!')
self._pd = float(val)
def N(self, val: int) -> None:
"""Set the number of increments."""
if not isinstance(val, (int, np.int)):
raise ValueError(
f'Expected integer, instead got {val} with type {type(val)}')
if not is_pos(val):
raise ValueError(f'Expected non-negative int, instead got {val}')
self._N = val
def T(self, val: float) -> None:
"""Set the time to maturity."""
if not is_pos(val):
raise ValueError(
f'Expected non-negative float, instead got {val} with type '
f'{type(val)}!')
if val == 0:
raise ValueError(f'T cannot be set to zero, got {val}')
self._T = float(val)
def M(self, val: int) -> None:
"""Set the number of underlying increments."""
if not isinstance(val, (int, np.int)):
raise ValueError(
f'Expected integer, instead got {val} with type {type(val)}'
)
if not is_pos(val):
raise ValueError(f'Expected non-negative int, instead got {val}')
self._M = val
self.s_steps = np.arange(val)