Returns the same type of function for generating random numbers but where the given random number generator source is used as the source of randomness instead of Math.random. This is useful when a seeded random number generator is preferable to Math.random.
Source (pseudo-)random number generator implementing the Math.random interface. The given random number generator must implement the same interface as Math.random and only return values in the range [0, 1).
Returns a function for generating random numbers with a normal (Gaussian) distribution. The expected value of the generated numbers is mu, with the given standard deviation sigma. If mu is not specified, it defaults to 0; if sigma is not specified, it defaults to 1.