Machine-learning/chapter_4.py at master · che-ig/Machine-learning · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
"""
for iteration in range(25):
    pred = input * weight
    error = (pred - goal_pred) ** 2
    direction_and_amount = (pred - goal_pred) * input
    weight = weight - direction_and_amount

    print("Error:" + str(error) + " Prediction:" + str(pred))
"""

"""
for iteration in range(4):
    pred = input * weight
    error = (pred - goal_pred) ** 2
    delta = pred - goal_pred
    weight_delta = delta * input
    weight = weight - weight_delta
    print("Error:" + str(error) + " Prediction:" + str(pred))
"""

weight, goal_pred, input = (0.5, 0.8, 2)
alpha = 0.1


for iteration in range(20):
    print("-----\nWeight:" + str(weight))
    pred = input * weight
    error = (pred - goal_pred) ** 2
    weight_delta = (pred - goal_pred) * input
    weight = weight - alpha * weight_delta
    print("pred:" + str(pred) + "  Error:" + str(error) + "  Prediction:" + str(pred))