wanted: function for drawing simple network diagrams

We are looking for a simple way to draw diagrams with circles and lines.

Requirements: * creates a figure based on the results of a simulation (i.e. we need a function for matlab, not a separate tool like powerpoint) * a free function, not part of a paid toolbox * draws shapes (circle) and puts a label on each * places the shapes in a specific location * draws lines with arrows between the shapes * allows for the line thickness to be changed * (nice to have) allows for the colors of objects to be changed

Here is a diagram we have created and with the built in methods. We are looking for a function that does this more easily and perhaps more beautifully. http://i55.tinypic.com/1zz3z9e.jpg

We have already investigated these methods: - biograph toolbox (not free) - graphViz (might be ok, but looks complicated) - graphViz-like tools from file exchange (looks limited, i.e. arrow size cannot be changed) : http://www.mathworks.com/matlabcentral/fileexchange/27608-graphviz-like-tools-for-matlab

Thanks for any ideas!

Answer 1

[Kelly Kearney]

If you're okay with straight edges in the graphs (i.e. no need to route edges around nodes or anything like that), you can probably use gplot along with patch and text to get what you want. The gplot function is annoyingly limited in line customization and doesn't return individual handles for the lines it plots, but a series of calls to it can approximate what you want. I prefer to stay away from rectangle objects since they don't play well with axis limits, and use patch instead to generate my node objects.

Here's an example that more or less replicates your image:

 % The data

 x = [1 2 2 2 ]; % Node x coordinates
 y = [3 3 2 1];  % Node y coordinates
 lbl = cellstr(num2str((1:nx)')); % Node labels

 r = 0.4; % radius of nodes

 nx = length(x);

 adj = zeros(nx); % Adjacency matrix for edges,
 adj(1,2) = 1;    % values specify line width
 adj(1,3) = 2;
 adj(1,4) = 2;

 % The plot

 figure;
 axes;
 hold on;

 linewidth = unique(adj(adj>0));
 for il = 1:length(linewidth)
    h = findall(gca, 'type', 'line');
    gplot(adj == linewidth(il), [x' y']);
    hnew = setdiff(findall(gca, 'type', 'line'), h);
    set(hnew, 'linewidth', linewidth(il));
 end

 theta = linspace(0, 2*pi, 20)';
 xc = bsxfun(@plus, r .* cos(theta), x);
 yc = bsxfun(@plus, r .* sin(theta), y);

 patch(xc, yc, 'w');
 text(x,y,lbl);

 axis equal;

[Danielle Ripsman]

This was exactly what I was looking for, thanks! I did however notice an error (or well it crashed) nx = length(x); is used before it's assigned - it needs to come before line 3, rather than in line 5.

Answer 2

[Sean de Wolski]

Why not just use powerpoint/keynote/open office?

EDIT per clarification

doc rectangle  %rectangles/circles etc.
doc annotation  %arrows/text
doc patch %triangles

playing with these two functions should get you everything you need.

[Robert]

Thanks for your answer. We want to automatically generate this diagram based on the results of some other analysis in MATLAB. I have edited my requirements now.

Answer 3

[Daniel Shub]

If the figure does not have to be manipulated in MATLAB after it has been created, I would suggest using MATLAB to write code for PGF/TikZ and then compile with LaTeX. This would give you the automation you need and image quality that is hard to obtain with straight MATLAB.

http://www.texample.net/tikz/examples/computer-science-mindmap/