circular network chart (non-ribbon chord diagram)

Creates a circular graph/network with customisable nodes and edges. Supports multiple rendering methods, group layout, curvature control.

Basic usage and RenderingMethod

Data = [25,  0,  0, 22, 24, 25,  8,  0, 0;
         0, 14,  0,  0,  0,  0,  6,  4, 1;
         0,  0, 11,  0,  0,  0,  0,  0, 7;
         0,  0,  0, 22,  0, 20, 17,  0, 0;
         0,  0,  0,  0, 24,  3,  6,  3, 0;
         0,  0,  0,  0,  0, 25,  7,  0, 2;
         0,  0,  0,  0,  0,  0, 17,  0, 0;
         0,  0,  0,  0,  0,  0,  0, 11, 0;
         0,  0,  0,  0,  0,  0,  0,  0, 5];

% Input required: Upper triangular adjacency matrix
% Node radius is mapped from diagonal values; 
% edge width is mapped from off‑diagonal values (separate mappings).


%% Basic usage (default RenderingMethod : simple)
figure()
% Create circular network chart object and draw.
CN1 = circNetChart(Data);
CN1 = CN1.draw();

%% Change color (RenderingMethod : interp)
figure()
CList = [127, 91, 93; 187,128,110; 197,173,143;  59, 71,111; 104, 95,126;  76,103, 86; 
         112,112,124;  72, 39, 24; 197,119,106; 160,126, 88; 238,208,146]./255;

CN2 = circNetChart(Data);
CN2.RenderingMethod = 'interp';  % RenderingMethod : interp
CN2.NodeColor = CList;           % Change node color
% CN2.EdgeColor = CList;         % Change edge color (Edge color defaults to match node color)
CN2 = CN2.draw();

%% RenderingMethod : map
figure()
CN3 = circNetChart(Data);
CN3.RenderingMethod = 'map';     % RenderingMethod : map (Map values to colors) 
CN3 = CN3.draw();

colormap(turbo)
colorbar('FontName','Times New Roman', 'FontSize',15)

Node-Size-Lim and Edge-Width-Lim, Label, Curvature

Data = triu(randi([1, 20], [18, 18]));

%% Node-Size-Lim and Edge-Width-Lim
figure()
CN4 = circNetChart(Data);
% Node radius is mapped from diagonal values; 
% edge width is mapped from off‑diagonal values (separate mappings).
% The minimum non‑zero diagonal value maps to the first element of NodeSizeLim, 
% and the maximum maps to the second. (The same applies to EdgeWidthLim).
% If the two values of NodeSizeLim are equal, 
% all nodes will have the same size. (The same applies to EdgeWidthLim).
CN4.NodeSizeLim = [.05, .05];
CN4.EdgeWidthLim = [.01, .01];
CN4 = CN4.draw();

%% Label rotate and label porperties
figure()
CN5 = circNetChart(Data);
CN5.NodeSizeLim = [.05, .05];
CN5.EdgeWidthLim = [.01, .01];
CN5 = CN5.draw();

% Enable label rotation for better readability.
CN5.labelRotate('on')
% Set global label style: monospaced font, size 15.
CN5.setLabel('FontName', 'Monospaced', 'FontSize',15)
% Customize the 2nd label individually with blue color.
CN5.setLabelN(2, 'Color',[0,0,.8])

%% Curvature (Default : 0.5 | Straight line: 0 | Bezier curve: 1)
figure()
CN6 = circNetChart(Data);
CN6.NodeSizeLim = [.05, .05];
CN6.EdgeWidthLim = [.01, .01];
CN6.Curvature = 0;  % Straight line: 0
CN6 = CN6.draw();

figure()
CN7 = circNetChart(Data);
CN7.NodeSizeLim = [.05, .05];
CN7.EdgeWidthLim = [.01, .01];
CN7.Curvature = 1;  % Bezier curve: 1
% CN7.NodeColor = turbo(18);
CN7 = CN7.draw();

%% Node name
Data = triu(randi([1, 20], [5, 5]));
figure()
CN8 = circNetChart(Data);
CN8.NodeName = {'AAA','BBB','CCC','DDD','EEE'}; % Change node name
CN8 = CN8.draw();

Group

Data = triu(randi([1, 20], [40, 40]));
Data((rand(40) + eye(40)) < .9) = 0;

% Define node groups
Group = [ones(1,5), ones(1,5).*2, ones(1,8).*3, ones(1,12).*4, ones(1,8).*5, 1, 1];
groupName = {'Set-AAA','Set-BBB','Set-CCC','Set-DDD','Set-EEE'};

% CList = [127, 91,  93; 187, 128, 110; 197, 173, 143;  59,  71, 111; 104,  95, 126]./255;
CList = [78, 101, 155; 138, 140, 191; 184, 168, 207; 231, 188, 198; 253, 207, 158]./255;

%% Group
figure()
CN9 = circNetChart(Data);
CN9.NodeSizeLim = [.03, .03];
CN9.EdgeWidthLim = [.01, .01];
CN9.Curvature = .8;

CN9.NodeColor = CList(Group, :);  % Color nodes by group membership
CN9.RenderingMethod = 'interp';   % RenderingMethod : interp

% Group layout settings
CN9.Group = Group;                % Group assignment for each node
CN9.GroupSep = 1/4;               % Group gaps occupy 1/4 of the circle
% CN9.GroupName  = groupName;
% CN9.GroupLabelRadius = 1.35;


CN9 = CN9.draw();

% Enable label rotation for better readability.
CN9.labelRotate('on')
% Set global label style: monospaced font, size 12.
CN9.setLabel('FontName', 'Monospaced', 'FontSize',12)
% % Set global group label style: monospaced font, size 21.
% CN9.setGroupLabel('FontName', 'Monospaced', 'FontSize',21)


% Create legend for each group
[~, ind] = unique(Group);
legend(CN9.nodeHdl(ind), groupName, 'FontName', 'Monospaced', 'FontSize',12, 'Location','best')

A demo (Pi digit connectivity visualization)

%% Pi digit connectivity visualization (digits 1-1000)

% First 1000 digits of pi after decimal point
piStr = ['1415926535897932384626433832795028841971693993751058209749445923078', ...
    '1640628620899862803482534211706798214808651328230664709384460955058', ...
    '1723175359408128481117450284102701938521105559644622948954930381964', ...
    '4288109756659334461284756482337867831652712019091456485669234603486', ...
    '1045432664821339360726024914127372458700660631558817488152092096282', ...
    '9254091715364367892590360011330530548820466521384146951941511609433', ...
    '0572703657595919530921861173819326117931051185480744623799627495673', ...
    '5188575272489122793818301194912983367336244065664308602139494639522', ...
    '4737190702179860943702770539217176293176752384674818467669405132000', ...
    '5681271452635608277857713427577896091736371787214684409012249534301', ...
    '4654958537105079227968925892354201995611212902196086403441815981362', ...
    '9774771309960518707211349999998372978049951059731732816096318595024', ...
    '4594553469083026425223082533446850352619311881710100031378387528865', ...
    '8753320838142061717766914730359825349042875546873115956286388235378', ...
    '75937519577818577805321712268066130019278766111959092164201999'];

% Convert digit characters to group indices (1-10)
% Subtract 47 to map ASCII '0' (48) to group 1
Group = abs(piStr(1:1000)) - 47;

% Build adjacency matrix: connect each digit to its next neighbor (off-diagonal)
Data = diag(ones(1, 999), -1);

% Sort nodes by group for grouped layout
[Group, ind] = sort(Group);
Data = Data(ind, ind);              % Reorder adjacency matrix
Data = Data + Data.' + eye(1000);   % Make symmetric and add self-loops

% Define group (digit) names and custom colors
groupName = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9'};
colorList = [239, 65, 75; 230, 115, 48; 229, 158, 57; 232, 136, 85; 239, 199, 97;
             144, 180, 116; 78, 166, 136; 81, 140, 136; 90, 118, 142; 43, 121, 159] ./ 255;

% Create figure with black background
figure()
set(gca, 'Color', [0, 0, 0])

% Initialize circular network chart
CNPI = circNetChart(Data);

% Node and edge appearance (uniform sizes)
CNPI.NodeSizeLim   = [0.01, 0.01];
CNPI.EdgeWidthLim  = [0.005, 0.005];

% Group layout configuration
CNPI.Group              = Group;
CNPI.GroupSep           = 1/8;              % Gap between groups (1/8 of full circle)
CNPI.GroupName          = groupName;
CNPI.GroupLabelRadius   = 1.05;

% RenderingMethod : interp
CNPI.NodeColor         = colorList(Group, :);  
CNPI.RenderingMethod   = 'interp';            

% Edge curvature (full Bezier curve)
CNPI.Curvature = 1;

% Render the chart
CNPI = CNPI.draw();

% Hide individual node labels
CNPI.setLabel('Visible', 'off')

% Style group labels (digit labels around the circle)
CNPI.setGroupLabel('FontSize', 25, 'FontName', 'Monospaced', ...
                   'FontWeight', 'bold', 'Color', 'w')

GraphType : 'bi'

rng(6)
Data = rand(9,9).*(rand(9,9) > .5);
% Determine global value limits from non‑zero entries for consistent mapping across figures 
% (确定非零元素的全局数值范围，用于两张图统一的数值映射)
VLim = [min(Data(Data~=0)), max(Data(Data~=0))];


figure()
CN1 = circNetChart(Data, 'GraphType','bi');
CN1.EdgeWidthLim = [0.005, 0.04];          
CN1.EdgeValueLim = VLim;                   % Set value mapping range (设置数值映射范围)
CN1.NodeColor = turbo(9);                  % Node colors from turbo (节点颜色使用 turbo 配色)
CN1.RenderingMethod = 'source';            % Color edges by source node (按源节点对边着色)
CN1.EdgeAlpha = .6;                        % Set edge transparency (设置边透明度)
CN1 = CN1.draw();


%% % Plot only the edges whose source is node N (仅绘制源为 N 的边)
figure()
S = 2; % also try: 2, 4, 7, 9, ...
DataS = 0.*Data;
DataS(S, :) = Data(S, :);

CN2 = circNetChart(DataS, 'GraphType','bi');
CN2.NodeValue = max(max(Data, [], 1), max(Data, [], 2).');  % Keep original node values (保留原始节点值)
CN2.EdgeWidthLim = [0.005, 0.04];
CN2.EdgeValueLim = VLim;
CN2.NodeColor = turbo(9);
CN2.RenderingMethod = 'source';
CN2.EdgeAlpha = .6;
CN2 = CN2.draw();

Apply distinct colormaps to edges and nodes

cmpE = [247, 251, 255; 233, 242, 250; 219, 233, 246; 205, 224, 241; 187, 214, 235;
        164, 204, 227; 136, 190, 220; 107, 174, 214;  84, 158, 205;  61, 141, 196;
         42, 122, 186;  26, 104, 174;  12,  86, 160;   8,  67, 135;   8,  48, 107]./255;

% Define colormap for nodes (定义节点的配色)
cmpN = [247, 252, 253; 237, 248, 251; 225, 244, 246; 211, 239, 235; 189, 230, 222;
        160, 219, 205; 131, 207, 185; 102, 194, 164;  81, 183, 138;  61, 169, 111;
         44, 149,  83;  25, 130,  62;   5, 113,  48;   0,  91,  37;   0,  68,  27]./255;

% Generate random upper triangular data (生成随机上三角数据)
rng(11)
Data = triu(rand([15, 15])).*(1 - triu(rand([15, 15]), 1)>.8);

% Create circular network chart and set properties (创建圆形网络图并设置属性)
CN = circNetChart(Data);
CN.EdgeWidthLim = [.01, .05];   % Edge width range (边宽范围)
CN.Curvature = 0;               % Straight edges (直线边)
CN.RenderingMethod = 'map';     % Use colormap mapping (使用颜色映射)
CN.EdgeAlpha = .6;              % Edge transparency (边透明度)
CN.EdgeOrder = 'ascend';        % Draw edges from small to large (从小到大绘制边)
CN.draw()                       
set(CN.nodeHdl, 'EdgeColor','k', 'LineWidth',2)

% Apply node colormap and add colorbar (应用节点配色并添加颜色条)
cbarN = CN.setNodeColorByColormap(cmpN);
cbarN.Position = [.78, .11, .02, .35];
set(cbarN.Label, 'String','Node Value', 'FontSize',17, 'FontName','Times New Roman');

% Apply edge colormap and add colorbar (应用边配色并添加颜色条)
colormap(CN.ax, cmpE)
cbarE = colorbar(CN.ax);
cbarE.Position = [.78, .575, .02, .35];
set(cbarE.Label, 'String','Edge Value', 'FontSize',17, 'FontName','Times New Roman');

Display both positive and negative correlations

% Define a diverging colormap for positive/negative values (定义用于正负值的发散配色)
cmp = [103,   0,  31; 157,  17,  40; 193,  55,  58; 218, 106,  85; 240, 155, 122;
       249, 196, 169; 251, 227, 213; 247, 247, 246; 220, 234, 242; 182, 215, 232;
       135, 190, 218;  78, 154, 199;  48, 121, 182;  25,  87, 151;   5,  48,  97]./255;

rng(1)
Data = triu(rand([15, 15]) - .5) .* (rand([15,15]) > .8);

% Create circular network chart (创建圆形网络图)
CN = circNetChart(Data);
CN.NodeSizeLim = [.05, .05];   % Fixed node size (固定节点大小)
CN.NodeValue = ones(1, 15);    % Uniform node values (统一节点值)
CN.RenderingMethod = 'map';    % Color edges by value (按值对边上色)
CN.EdgeOrder = 'ascend';       % Draw edges from small to large (从小到大绘制边)
CN.EdgeAlpha = .6;             % Edge transparency (边透明度)
CN.draw()                      

colormap(cmp)
colorbar()
clim([-.5, .5])