How to set colorspace of line in special code of graph?

G = graph(index_s,index_t,weighted);
p1 = plot(G,'XData',X1,'YData',Y1);

What I want to change is the color of lines. Have anyone can help me ?

Answer 1

[Steven Lord]

There's no need to create additional lines to change the colors of lines in a GraphPlot. highlight them instead.

% Create graph 
s = [1 1 1 2 2 3 3 4 5 5 6 7];
t = [2 4 8 3 7 4 6 5 6 8 7 8];
G = graph(s,t); 

% Plot the graph with blue edges
h = plot(G, 'EdgeColor', 'b');

% Change the EdgeColor, LineWidth, and LineStyle properties of the edge (3, 4)
highlight(h, 3, 4, 'EdgeColor', 'r', 'LineWidth', 6, 'LineStyle', ':')

% Change the Marker and MarkerSize properties of nodes 1, 3, 5, and 7
highlight(h, 1:2:7, 'Marker', '+', 'MarkerSize', 16)

[z cy]

Thanks！ I have changed it based on your method. Thanks again!

[z cy]

Hello. I have another question to ask you. I want to set MarkerEdgeColor of point. Can you help me ? Thanks

[Steven Lord]

I don't believe we offer the capability to change the edge color of the markers indepedently of the main body of the markers (which you control with NodeColor.)

[Adam Danz]

In that case, my answer is somewhat useful. You can plot another marker on top of a node and set it's EdgeColor.

hold on
hNew = plot(h.XData(3), h.YData(3), 'ro', 'LineWidth', 1);
linkprop([h,hNew],{'Marker','MarkerSize'}) % make sure marker props match

however, if the node properties are different between nodes, these properties will no longer be scalar and you'll need to index them.

hold on
hNew = plot(h.XData(3), h.YData(3), ...
    'MarkerEdgeColor', 'r', ...
    'LineWidth', 1, ...
    'Marker', h.Marker{3}, ...
    'MarkerSize', h.MarkerSize(3), ...
    'MarkerFaceColor', 'none')

Answer 2

[Adam Danz]

Change the color of all graph edges

plot(G, . . ., 'r')        % red
plot(G, . . ., [.5 0 .5])  % purple

Change the colors of a specific graph edges

See Steven Lord's answer.

Plot new lines on top of edges

I'm not sure how this would be useful but I'll leave it here because it's already written up.

You can use the XData and YData property of the GraphPlot object to re-plot a line segment on top of the existing one.

% Create graph 
s = [1 1 1 2 2 3 3 4 5 5 6 7];
t = [2 4 8 3 7 4 6 5 6 8 7 8];
G = graph(s,t); 
h = plot(G); 

% set color of segment 3-4 to red
hold on
hNew = plot(h.XData(3:4), h.YData(3:4), 'r-'); 
linkprop([h,hNew],{'LineStyle','LineWidth'}) % make sure line props match

To set all graph edges to different colors,

% Create graph 
s = [1 1 1 2 2 3 3 4 5 5 6 7];
t = [2 4 8 3 7 4 6 5 6 8 7 8];
G = graph(s,t); 
h = plot(G); 

% set color of segment 3-4 to red
hold on
colors = jet(numel(h.XData)); 
hNew = line([h.XData(:)'; circshift(h.XData(:)',1)], ...
    [h.YData(:)'; circshift(h.YData(:)',1)]); 
set(s, {'Color'}, mat2cell(colors,ones(size(colors,1),1),3))
linkprop([h,hNew'],{'LineStyle','LineWidth'}) % make sure line props match

[Steven Lord]

There's no need to create additional lines to change the colors of lines in a GraphPlot. highlight them instead.

% Create graph 
s = [1 1 1 2 2 3 3 4 5 5 6 7];
t = [2 4 8 3 7 4 6 5 6 8 7 8];
G = graph(s,t); 

% Plot the graph with blue edges
h = plot(G, 'EdgeColor', 'b');

% Change the EdgeColor, LineWidth, and LineStyle properties of the edge (3, 4)
highlight(h, 3, 4, 'EdgeColor', 'r', 'LineWidth', 6, 'LineStyle', ':')

% Change the Marker and MarkerSize properties of nodes 1, 3, 5, and 7
highlight(h, 1:2:7, 'Marker', '+', 'MarkerSize', 16)

[Adam Danz]

Thanks, Steven Lord. I wasn't aware of the highlight function. Your comment should probably be an (accepted) answer.

[z cy]

Thank you very much！