distribution.zip_matlab_分布函数

clc close all clear all beta = 1; alph = 0:0.5:4; x = 0:.1:3; mu = 0; % mean zero sig = 0.5:0.5:1.5; % standard deviation for i = 1:length(x) for j = 1:length(alph) K = -(x(i)/beta); G(i,j) = (beta^-alph(j))*x(i)^(alph(j)-1)*exp(K)/(gamma(alph(j))); % gamma distribution KG = -(x(i)/beta)^(alph(j)); W(i,j) = alph(j)*(beta^-alph(j))*(x(i)^(alph(j)-1))*exp(KG); % Weibull density Wd(i,j) = 1-exp(KG); % Weibull distribution end end for i = 1:length(x) for j = 1: length(alph)-1 T = -(x(i)/beta); TF(i,j) = 1-T*((x(i)/beta)^(j)/factorial(j)); end TFF(i) = sum(TF(i,:)); end figure(1) subplot(221) plot(x,G) legend('\alpha = 0','\alpha = 0.5','\alpha = 1','\alpha = 2','\alpha = 3'); title('Gamma density function '); ylabel('f(x)'); subplot(222) plot(x,W) legend('\alpha = 0','\alpha = 0.5','\alpha = 1','\alpha = 2','\alpha = 3'); title('Weibull density function'); ylabel('f(x)'); subplot(223) plot(x,Wd) legend('\alpha = 0','\alpha = 0.5','\alpha = 1','\alpha = 2','\alpha = 3'); title('Weibull distribution function'); ylabel('F(x)'); subplot(224) plot(x,TF) legend('\alpha = 0','\alpha = 0.5','\alpha = 1','\alpha = 2','\alpha = 3'); title('Gamma distribution function');ylabel('F(x)'); for i = 1:length(x) for j = 1:length(sig) KK = -((log(x(i))- mu)^2)/(2*sig(j)^2); F(i,j) = (1/(x(i)*sqrt(2*pi*sig(j)^2)))*(exp(KK)); % log normal density function end end figure(2) plot(x,F) legend('\sigma = 0.5','\sigma = 1','\sigma = 1.5');