[R] does save.image() also save the random state?

[Duncan Murdoch]

On 05/02/2016 11:14 AM, Jinsong Zhao wrote:
> Dear there,
>
> Here is a snipped code,
>
>   > rm(list = ls())
>   > x <- 123
>   > save.image("abc.RData")
>   > rm(list = ls())
>   > load("abc.RData")
>   > sample(10)
>    [1]  3  7  4  6 10  2  5  9  8  1
>   > rm(list = ls())
>   > load("abc.RData")
>   > sample(10)
>    [1]  3  7  4  6 10  2  5  9  8  1
>
> you will see that, after loading a abc.RData file that is saved by
> save.image(), sample(10) gives the same results. I am wondering whether
> it's designed purposely. And if it is, how can I get a different results
> of sample(10) every time after loading the saved image?

This happens because you are reloading the random number seed.  You can 
tell R to ignore it by calling

set.seed(NULL)

just after you load the image.  See ?set.seed for more details.

Duncan Murdoch