如何遍历矩阵，通过计算改变浮点数?

Question

我有以下列表：

N_division_n = [0.0, 1.0, 0.4150374992788437]

我有以下矩阵：

sample_collection =
[['', 'test1.txt', 'test2.txt', 'test3.txt', 'test4.txt'], 
['apple', 1.0, 1.0, 1.0, 1.0], 
['banana', 1;0, 1.0, 0.0, 0.0], 
['lemon', 1.0, 0.0, 2.0, 1.0]]

我想将矩阵行中的所有值与前面列表中的相应值相乘。像这样：apple values * 0.0, banana values * 1.0, lemon values * 0.4150374992788437.

我尝试构建以下内容，但它不想遍历浮点数，我不确定如何解决它。

def tf_df_calculation(sample_collection):
for a in range(1,len(sample_collection)):
tf_df_list = [item[a] for item in N_division_n]
value_a = 0
for i in tf_df_list:
if type(i) is float:
value_a = i * N_division_n
sample_collection.append(value_a)
tf_df_calculation(sample_collection)

预期输出：

[['', 'test1.txt', 'test2.txt', 'test3.txt', 'test4.txt'], 
['apple',  0.0, 0.0, 0.0, 0.0], 
['banana',  1.0, 1.0, 0.0, 0.0], 
['lemon',  0.41503749927884376, 0.0, 0.8300749985576875, 0.41503749927884376]]

Answer 1

这个简单的函数有效，但它使用两个 for 循环。无论如何，如果您的矩阵很小，这不是问题。

N_division_n = [0.0, 1.0, 0.4150374992788437]
sample_collection = [['', 'test1.txt', 'test2.txt', 'test3.txt', 'test4.txt'], 
['apple', 1.0, 1.0, 1.0, 1.0], 
['banana', 1.0, 1.0, 0.0, 0.0], 
['lemon', 1.0, 0.0, 2.0, 1.0]]
def tf_df_calculation(sample_collection):
for a in range(1,len(sample_collection)):
for b in range(1,len(sample_collection[a])):
sample_collection[a][b] *= N_division_n[a-1]
tf_df_calculation(sample_collection)
print(sample_collection)

输出

[['', 'test1.txt', 'test2.txt', 'test3.txt', 'test4.txt'], ['apple', 0.0, 0.0, 0.0, 0.0], ['banana', 1.0, 1.0, 0.0, 0.0], ['lemon', 0.4150374992788437, 0.0, 0.8300749985576874, 0.4150374992788437]]

Answer 2

你来了：

N_division_n = [0.0, 1.0, 0.4150374992788437]
sample_collection =[['', 'test1.txt', 'test2.txt', 'test3.txt', 'test4.txt'], ['apple', 1.0, 1.0, 1.0, 1.0], ['banana', 1.0, 1.0, 0.0, 0.0], ['lemon', 1.0, 0.0, 2.0, 1.0]]
results = [sample_collection[0]]
count = 0
for sample in sample_collection[1::]:
calculated_line = [sample[0]] + [x*N_division_n[count] for x in sample[1::]]
results.append(calculated_line)
count += 1

输出：

[['', 'test1.txt', 'test2.txt', 'test3.txt', 'test4.txt'], ['apple', 0.0, 0.0, 0.0, 0.0], ['banana', 1.0, 1.0, 0.0, 0.0], ['lemon', 0.4150374992788437, 0.0, 0.8300749985576874, 0.4150374992788437]]