用於在Matlab的變量分組

Question

假設我們有一個包含分組被叫group可變信息設計邏輯

group = [ {1}, {2}, ..., {D} ] 

我們必須維持一個計數器，用於每對(i, j)其中i，j是在[1 d的範圍]和所有這些對，其中count(i, j) >= 5，這些對被合併。

例：

D = 5 
group = [ {1}, {2}, {3}, {4}, {5} ] 
(1, 2) = 7 
(2, 3) = 10 
(3, 4) = 2 
(4, 5) = 20 

因此對合並並將所得組是

group = [ {1 2 3}, {4 5} ] 

在我的問題

D可以有1000值，什麼是實現這個的有效途徑邏輯

Answer 1

您可以使用count>=5作爲鄰接矩陣a第二生成：

% generating random count matrix 
D = 20; 
count = zeros(D); 
count(randsample(D^2,round(D/2))) = 10; 
% find connections 
A = count >= 5; 
% A is symmetric - if (1,2) so (2,1) as well 
A = A | A'; 
% build graph 
G = graph(A); 
% get connected components labeling from graph 
idxs = G.conncomp; 
% generate groups of nodes 
nodes = num2cell(1:max(idxs)); 
group = cellfun(@(g) find(g == idxs),nodes,'UniformOutput',0); 
% plot graph 
plot(G)