Today is windy. What is the probability that three days from now it will be raining if we have the weather transition matrix?

```
import numpy as np
indices = ['rainy', 'sunny', 'cloudy', 'windy']
indices_len = len(indices)
weather_probabilities = np.array([
[0.3, 0.3, 0.3, 0.1],
[0.25, 0.2, 0.35, 0.2],
[0.2, 0.3, 0.2, 0.3],
[0.35, 0.2, 0.3, 0.15],
])
assert np.allclose(np.sum(weather_probabilities, axis=1), np.ones(indices_len)) == True
today, future = 'rainy', 'sunny'
today_idx = indices.index(today)
future_idx = indices.index(future)
days_from_now = 3
today_vec = future_vec = np.zeros(indices_len)
today_vec[today_idx] = 1
print(np.dot(today_vec, weather_probabilities**days_from_now)[future_idx]) # 0.027 or 2.7%
```

**Note:** This is an approximate model that gets progressively inaccurate over time.