Stochastic process uses the Random Number Generator(RNG). It uses a given point \((t,x)\) and a time step \(\Delta t\) to calculate the expectation and variance. The class StochasticProcess1D is 1-dimensional stochastic process, and it cooperates with Cox-Ingersoll-Ross and Extended Cox-Ingersoll-Ross Models. The stochastic process can be described as
\[dx_{t}=\mu(t,x_{t})dt+\sigma(t,x_{t})dW_{t}\]