Linear Congruential generator

This is a basic explanation of linear congruental generator, a method of generating random numerical values, the generating formulae is described by the equation

X_n+1 = (A x X_n+B) Mod M

A,B and M are constants
The value X used to initialize the sequence is called the seed. The sequence of numbers generated are random however they have a period in which the whole function repeat its values, making it a random but a predictable generator.

The implementation of this algorithm in javascript would be as follows

var m =11,
    a =7,
    c =5;
var z = 0;

var rand = function(){

z=(a*z+c)%m;

return z;
};

for(i=0;i<20;i++){
  console.log(rand());
}

Comments

[Eric Ahnell]

So this might be a foundational piece of a more complex PRNG - as all of these are periodic, but the highly valued ones have periods long enough to not get hit in practice. Thanks!