Populating a nested cell as a tree using treeplot: MATLAB

Question

I have a complex cell that represents a tree structure:

CellArray = {1,1,1,{1,1,1,{1,1,{1,{1 1 1 1 1 1 1 1}, 1,1}, 1,1},1,1,1},1,1,1,{1,1,1,1}};

I want to build a representative tree from it with treeplot(p), but I'm not sure how to build an array pso that it displays correctly.

Answer 1

We can create a recursive function that examines your array of cells and creates an array of tree pointers (as described in docs ) for each node parent.

(, , ), , .

---

treebuilder :

• , node , node number 1
• , treebuilder , node , ( ).
• - 2, , .

---

:

function treearray = getTreeArray(cellarray)
    % initialise the array construction from node 0
    treearray = [0, treebuilder(cellarray, 1)]; 
    % recursive tree building function, pass it a cell array and root node
    function [out, node] = treebuilder(cellarray, rnode)
        % Set up variables to be populated whilst looping
        out = []; 
        % Start node off at root node
        node = rnode;
        % Loop over cell array elements, either recurse or add node
        for ii = 1:numel(cellarray)
            tb = []; node = node + 1;
            if iscell(cellarray{ii})
                [tb, node] = treebuilder(cellarray{ii}, node);
            end
            out = [out, rnode, tb];   
        end
    end
end

---

, , .

myCellArray = {1 1 {1 1 1 {1 1 1}}};
% This cell array has 3 levels: 
% - 3 child nodes (2,3,4) of the root node (1) 
% - Last node on the first level (4) has 4 children:
%     - 4 child nodes on second level (5,6,7,8) 
%     - Last node on the first level (8) has 3 children:
%         - 3 child nodes on third level (9,10,11)
myTreeArray = getTreeArray(myCellArray);
% Output, we see the corresponding nodes as listed above:
% [0 1 1 1 4 4 4 4 8 8 8]
treeplot(myTreeArray)

---

, , , , myCellArray myTreeArray:

treeplot(getTreeArray({1,1,1,{1,1,1,{1,1,{1,{1 1 1 1 1 1 1 1}, 1,1}, 1,1},1,1,1},1,1,1,{1,1,1,1}}))

, , . , !

---

:

, , treelayout . "" :

function [treearray, nodevals] = getTreeArray(cellarray)
    % initialise the array construction from node 0
    [nodes, ~, nodevals] = treebuilder(cellarray, 1); 
    treearray = [0, nodes];
    % recursive tree building function, pass it a cell array and root node
    function [out, node, nodevals] = treebuilder(cellarray, rnode)
        % Set up variables to be populated whilst looping
        out = []; nodevals = {};
        % Start node off at root node
        node = rnode;
        % Loop over cell array elements, either recurse or add node
        for ii = 1:numel(cellarray)
            node = node + 1;
            if iscell(cellarray{ii})
                [tb, node, nv] = treebuilder(cellarray{ii}, node);
                out = [out, rnode, tb];  
                nodevals = [nodevals, nv];
            else
                out = [out, rnode];
                nodevals = [nodevals, {node; cellarray{ii}}];
            end 
        end
    end
end

. node node, , node .

, node. , , nodevals .

, ,

% Run the tree building script above
[treearray, nodevals] = getTreeArray(myCellArray);
% Plot
treeplot(treearray);
% Get the position of each node on the plot  
[x,y] = treelayout(treearray);
% Get the indices of the nodes which have values stored
nodeidx = cell2mat(nodevals(1,:));
% Get the labels (values) corresponding to those nodes. Must be strings in cell array
labels = cellfun(@num2str, nodevals(2,:), 'uniformoutput', 0);
% Add labels, with a vertical offset to the y coords so that labels don't sit on nodes
text(x(nodeidx), y(nodeidx) - 0.03, labels);

myCellArray = {{17, 99.9}, 50}, , , node "