Follow the weather

來源: 移花接木於 2024-03-01 08:04:06 [檔案] [博客] [舊帖] [給我悄悄話] 本文已被閱讀：次 (4603 bytes)

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這次不是google 翻譯，是我直接寫的中文，也是直接寫的英文。

跟著天氣預報製定自己的出行或者公平賭博，實際上是在玩概率遊戲。上幾周我一直盡可能地坐公交車，所以更加關心天氣預報，我發現天氣預報的準確度極低，誇張點說10%的準確度，不必較真，反正很低就是了。10%的準確度其實一點都不差，別以為我在開玩笑，真的是不差。

適當更正一下，其實吧，天氣預報晴天還是大差不差，是雨天預報準確度大約是10%

關於準確度的概率有時候就會比較那什麽什麽，不讓人省心。

先問個問題：最壞的預測準確率是多少？ 1%，2%，0%？

都不是啊，最差的預測準確率是50%, 這是最低的贏率。如果預測準確度高於50%，我們就按照預測出牌straight forward. 如果預測準確度低於50%, 我們就不按預測出牌，"Straight backward"（這個短語是我發明的嗎？），運用反向邏輯下注。如果天氣預報準確率10%, 預報有雨，我就當它沒雨，贏麵90%。

本周二，天氣預報有雨，我運用反向邏輯，沒雨。出門走路坐公交不帶雨具，這次那10%贏了，下雨了，我在雨裏走了20分鍾。第二天，周三，仍然預報有雨，我做出了一個犯兵家大忌的決定：change horses in midstream, 改用了正向邏輯，聽信天氣預報，開車，在雨裏洗車，這次那90%贏了，一滴雨都沒下。我浪費一天走路的機會, 車也沒洗成。

今天，其實是昨天周四，天氣預報早晨就開始下雪，低溫。也是這是本冬天最後一個冷天了，我可不想錯過，零下10度的溫度，我覺得自己舒適活躍。而且我也想在下雪時走路。我又坐公交車了。這次的決定似乎是穩贏不輸，下不下雪我都走路。但天氣預報概率再次證明與10%不維和。都到了下午了，太陽還是那麽燦爛。一直盼到下班雪也沒下。

以後還這麽玩，也不會采取任何防雨預備措施。

今天天氣預報說: Tonight sunshine.

Following the weather forcast or playing fair gamble, what we are really playing is a probability game.

From my last few weeks experience, i.e. I became more weather concerned since I started taking public transportation, I found that my local weather forcast accuracy is about 10%. That's not bad at all. You might think I am joking that I meant 10% is better than 0%. Nope, I am serious, and 10% is no better than 0%.

Probability becomes tricky at certain point.

Q: What is the worst prediction accuracy 1%, 2%, or 0% ?

None of them, the worst is 50%, it is the lowest winning rate. If the accuracy is higher than 50% we follow the prediction, straight forward. If the accuracy is lower than 50% (learned from our statistic) we just reverse our decision from the prediction, "straight backward". We bid with reverse logic. If the weather accuracy is 10% , we do the opposite from what the forcast says we get 90% winning chances.

This Tuesday I used reversed logic ignoring the rain forcast, I should have 90% chances of winning.

But I was caught by the 10% rain. The next day, Wednesday, I changed my horse in midstream, I followed the weather forcast of rain, I drove and expected to get my car washed by the rain, this time fate faved the 90%, i.e. no rain; rain never came down, I lost a day's hiking fun.

Today, the weather said snow and cold, this could be the last cold day of this winter, I didn't want to miss this. My body can be very active at around -10C, and I want to embrace the snow fall. Up to this point the sun still shines. Where is my appointed snow?

Anyway, to me, it is an all winning game, I get my walking in a chill at least, and I won't take any weatherproof action in the future. I am really having fun.