I am using the xfp package to generate some random numbers, and am trying to figure out how to specify a specific random seed for the pseudo random number generator (so it gives the same results whenever compiled with a given seed).

Here is a minimal code example:

% TODO: set specific random seed here

A random integer between 0 and 10: $\fpeval{randint(0,10)}$

I know that xfp is an interface to expl3, in which one can set a random seed using \sys_gset_rand_seed:n. However, I don't know how to do so in my document. Any help is much appreciated.

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    \ExplSyntaxOn\sys_gset_rand_seed:n{100}\ExplSyntaxOff Oct 2, 2021 at 21:19

1 Answer 1


Access the expl3 programming environment:

\sys_gset_rand_seed:n {42}

Use an integer between 0 and 228 − 1.

If you need to set the seed several times, you can define an interface:

\cs_new_eq:NN \setrandomseed \sys_gset_rand_seed:n

and then use \setrandomseed{42} at the appropriate spot.

  • Great, thanks so much!
    – Bob
    Oct 2, 2021 at 21:54

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