这是我的线性系统代码。 times_scalar函数在Vector对象中定义。执行multiply_coefficient_and_row函数时，我得到AttributeError: 'tuple' object has no attribute 'times_scalar'。我尝试了不同的东西，包括将元组转换为列表并返回元组但没有成功。
from decimal import Decimal, getcontext
from copy import deepcopy
from Vector import Vector
from Plane import Plane
getcontext().prec = 30
class LinearSystem(object):
ALL_PLANES_MUST_BE_IN_SAME_DIM_MSG = 'All planes in the system should live in the same dimension'
NO_SOLUTIONS_MSG = 'No solutions'
INF_SOLUTIONS_MSG = 'Infinitely many solutions'
def __init__(self, planes):
try:
d = planes[0].dimension
for p in planes:
assert p.dimension == d
self.planes = planes
self.dimension = d
except AssertionError:
raise Exception(self.ALL_PLANES_MUST_BE_IN_SAME_DIM_MSG)
def swap_rows(self, row1, row2):
self[row1], self[row2] = self[row2], self[row1]
def multiply_coefficient_and_row(self, coefficient, row):
n = self[row].normal_vector.coordinates
k = self[row].constant_term
new_normal_vector = n.times_scalar(coefficient)
new_constant_term = k * coefficient
self[row] = Plane(normal_vector = new_normal_vector, constant_term = new_constant_term)
def add_multiple_times_row_to_row(self, coefficient, row_to_add, row_to_be_added_to):
n1 = self[row_to_add].normal_vector.coordinates
n2 = self[row_to_be_added_to].normal_vector.coordinates
k1 = self[row_to_add].constant_term
k2 = self[row_to_be_added_to].constant_term
new_normal_vector = n1.times_scalar(coefficient).plus(n2)
new_constant_term = (k1 * coefficient) + k2
self[row_to_be_added_to] = Plane(normal_vector = new_normal_vector, constant_term = new_constant_term)
def indices_of_first_nonzero_terms_in_each_row(self):
num_equations = len(self)
num_variables = self.dimension
indices = [-1] * num_equations
for i,p in enumerate(self.planes):
try:
indices[i] = p.first_nonzero_index(p.normal_vector.coordinates)
except Exception as e:
if str(e) == Plane.NO_NONZERO_ELTS_FOUND_MSG:
continue
else:
raise e
return indices
def __len__(self):
return len(self.planes)
def __getitem__(self, i):
return self.planes[i]
def __setitem__(self, i, x):
try:
assert x.dimension == self.dimension
self.planes[i] = x
except AssertionError:
raise Exception(self.ALL_PLANES_MUST_BE_IN_SAME_DIM_MSG)
def __str__(self):
ret = 'Linear System:\n'
temp = ['Equation {}: {}'.format(i+1,p) for i,p in enumerate(self.planes)]
ret += '\n'.join(temp)
return ret
class MyDecimal(Decimal):
def is_near_zero(self, eps=1e-10):
return abs(self) < eps
来自Vector类此times_scalar函数：
def times_scalar(self, c):
new_coordinates = [Decimal(c) * x for x in self.coordinates]
return Vector(new_coordinates)