www.gusucode.com > stats 源码程序 matlab案例代码 > stats/GenerateRandomSamplesUsingTheJohnsonSystemExample.m
%% Generate Random Samples Using the Johnson System % This example shows several different approaches to using the Johnson % system of flexible distribution families to generate random numbers and % fit a distribution to sample data. % Copyright 2015 The MathWorks, Inc. %% % Generate random values with longer tails than a standard normal. rng default; % For reproducibility r = johnsrnd([-1.7 -.5 .5 1.7],1000,1); figure; qqplot(r); %% % Generate random values skewed to the right. r = johnsrnd([-1.3 -.5 .5 1.7],1000,1); figure; qqplot(r); %% % Generate random values that match some sample data well in the right-hand % tail. load carbig; qnorm = [.5 1 1.5 2]; q = quantile(Acceleration, normcdf(qnorm)); r = johnsrnd([qnorm;q],1000,1); [q;quantile(r,normcdf(qnorm))] %% % Determine the distribution type and the coefficients. [r,type,coefs] = johnsrnd([qnorm;q],0)