Find the coordinates of the nodes of an matrix inside another matrix

Question

Alberto Acri 2024-5-20

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2120561-find-the-coordinates-of-the-nodes-of-an-matrix-inside-another-matrix

回答： Matt J 2024-5-21

nodes.mat

I would like to find the coordinates of the nodes of an matrix 'nodes_portion' inside a larger matrix 'nodes_e'. (In this case all 'nodes_portion' is contained in 'nodes_e').

What I want to get are the rows where the nodes of 'nodes_portion' are inside 'nodes_e'.

I am using a for loop however it takes much longer than expected. Any way to optimize the search?

nodes_file = importdata("nodes.mat");
nodes_e = nodes_file.nodes_e;
nodes_portion = nodes_file.nodes_portion;
    row_t = {};
    
    for j = 1:5 %:height(nodes_portion)
    
        row = {};
        for k = 1:height(nodes_e)
            [r,~] = find(nodes_e(k,1) == nodes_portion(j,1) & nodes_e(k,2) == nodes_portion(j,2) & nodes_e(k,3) == nodes_portion(j,3));
            row = [row;{r}];
        end
    
        row_t = [row_t;{row}];
    
    end
    % ==========
    
    rr = {};
    for s = 1:height(row_t)
        [r,c] = find(cellfun(@(x) isequal(x,1), row_t{s,1}(:,1)));
        rr = [rr;{r}];
    end