1.13.1.33 rand

`rand(0)` returns a pseudo random number in the interval [0:1] generated

           from the current value of two internal 32-bit seeds.

`rand(-1)` resets both seeds to a standard value. `rand(x)` for x>0 sets both seeds to a value based on the value of x. `rand({x,y})` for x>0 sets seed1 to x and seed2 to y. Note: This behavior has changed starting with gnuplot version 3.8l. Older scripts that expected rand(x>0) to produce sequential pseudo-random numbers from the same seeded sequence must be changed to call rand(0) instead.