Random Processes Course - Matlab examples

The sections follow the chapters of Part I of the textbook. Every file is a standalone script that prints the theoretical values next to the simulated ones. Most scripts need only base MATLAB; the few optional toolbox calls are noted in the file headers.

Discrete Random Variable

  • Empirical PDF of a fair die (code)
  • Rolling a pair of dice (code)
  • Sum of Bernoulli variables is binomial (code)

Continuous Random Variable

  • Moments of \(Y=X^2+1\), \(X\sim\mathrm{Exp}(\lambda)\), as a function of the number of experiments (code)
  • Number of Bernoulli draws until the first “1” is geometric (code)
  • \(\Pr\left(X^{1/4}<1/2\right)=1/16\) for \(X\sim\mathrm{U}[0,1]\) (code)
  • Estimating a PDF value from a single histogram bin (code)
  • The Q-function by simulation (code)
  • Central limit theorem: a sum of many \(\pm1\) variables (code)

Two Random Variables

  • Sum of two fair dice, empirical vs exact distribution (code)
  • \(\Pr\left(X^{1/3}>Y/2\right)=31/32\) for two independent uniform variables (code)
  • Joint CDF of a bivariate Gaussian (code)
  • Gaussian marginals without a jointly Gaussian pair (code)

Linear Prediction

  • Optimal linear predictor for a correlated pair (code)
  • Linear prediction for a bivariate Gaussian pair (code)
  • Dependent but uncorrelated: \(Y\approx X^2\Rightarrow\rho_{XY}=0\) (code)
  • Quadratic vs linear predictor (code)

Descriptive Statistics

  • Biased vs unbiased variance estimators (code)
  • Monte-Carlo error vs the number of experiments (code)
  • Sample skewness and excess kurtosis (code)

Statistical Plots

  • The bin-width trade-off (code)
  • Fluctuation of histogram bin counts (code)
  • Boxplot vs violin plot of bimodal data (code)
  • Fitting a distribution to a pdf histogram (code)

Uni-Variate Linear Least-Squares

  • A complete uni-variate fit by hand (code)
  • How large a correlation coefficient pure noise can produce (code)
  • Training MSE against the sample size (code)
  • Reading \(\vert r_{xy}\vert\) off a scatter plot (code)