RandPCG

A random number generator using the PCG algorithm.

Documentation: https://hexdocs.pm/rand_pcg/

Installation

1. Add rand_pcg to your list of dependencies in mix.exs:

```elixir
def deps do
  [{:rand_pcg, "~> 0.1.2"}]
end
```

2. If you are using the GenServer option, ensure rand_pcg is started before your application:

```elixir
def application do
  [applications: [:rand_pcg]]
end
```

Examples

GenServer Option

Get Some Random

# Random 32 bit integer
RandPCG.random()

# Random 32 bit based float
RandPCG.random(:float)

# n Random 32 bit integers
RandPCG.random(n)

# Random nth of an enumerable
list = [:a, :b, :c]
RandPCG.random(list)

# Random integer x where min <= x <= max
RandPCG.random(min, max)

# n random integers x where min <= x <= max
RandPCG.random(min, max, n)

Set State

state = %RandPCG.State{seed: 234532454323451, inc: 1}
RandPCG.state(state)

Note

The initial seed is based on :os.system_time(:micro_seconds)

Without running the GenServer

You will have to maintain your own state of the random number generator.

Random 32 bit Integer

state = RandPCG.PCG.gen_state()
random_int_32 = RandPCG.PCG.xsh_rr(state)
state = advance(state)

If you do not advance the state, you will receive the same random number.

Random Integer in a Range

state = RandPCG.PCG.gen_state()
min = 1
max = 10
random_1_10_inclusive = RandPCG.PCG.rand_int(min, max, state)
state = advance(state)

RandPCG.PCG.gen_state initial seed is based on :os.system_time(:micro_seconds)

References

• PCG Random Number Generator Homepage
• PCG Basic C Implementation
• PCG Go Implementation was also helpful