关于set.seed()的技术问询：抽样有效性及最大取值

1. What's the maximum valid value for set.seed()? #

In R, the practical upper limit for a seed that won’t get automatically adjusted is 2^31 - 1 (which equals 2147483647). This comes from the 32-bit integer range that R’s default random number generator uses. If you pass a number larger than this, R will automatically take it modulo 2^31 to map it into the valid range. For example, set.seed(2147483648) would behave exactly like set.seed(0) because 2147483648 mod 2^31 equals 0.

2. Will set.seed(10000) guarantee the same subset every time when sampling 9000 observations from 100,000? #

Absolutely—here’s why:

• set.seed(10000) initializes R’s random number generator to a fixed state.
• As long as you run this line immediately before your sampling code every time, and keep your sampling logic identical (same function, same parameters like size = 9000, same source dataset), the sequence of random indices picked for your subset will be exactly the same.
• This reproducibility holds regardless of dataset size—whether you’re sampling 9000 from 100k or 10 from 100, a fixed seed paired with consistent code ensures you’ll get the exact same subset every run.

内容的提问来源于stack exchange，提问作者HW-Scientist