www.gusucode.com > stats 源码程序 matlab案例代码 > stats/ComputeTheMultinomialDistributionPdfExample.m
%% Compute the Multinomial Distribution pdf % % Copyright 2015 The MathWorks, Inc. %% % Compute the pdf of a multinomial distribution with a sample size of |n = % 10|. The probabilities are |p = 1/2| for outcome 1, |p = 1/3| for outcome % 2, and |p = 1/6| for outcome 3. p = [1/2 1/3 1/6]; n = 10; x1 = 0:n; x2 = 0:n; [X1,X2] = meshgrid(x1,x2); X3 = n-(X1+X2); %% % Compute the pdf of the distribution. Y = mnpdf([X1(:),X2(:),X3(:)],repmat(p,(n+1)^2,1)); %% % Plot the pdf on a 3-dimensional figure. Y = reshape(Y,n+1,n+1); bar3(Y) h = gca; h.XTickLabel = [0:n]; h.YTickLabel = [0:n]; xlabel('x_1') ylabel('x_2') zlabel('Probability Mass') title('Trinomial Distribution') %% % Note that the visualization does not show |x3|, which is determined by % the constraint |x1 + x2 + x3 = n|.