how create coordinate array?

hi,

I found this function to plot the graph of adjacency matrix.

http://stackoverflow.com/questions/5721377/plotting-a-graph-from-its-adjacency-matrix

The input is adj matrix and coordinates array, xy. I have adj matrix , but I do not know how create coordinate array.

please can anybody help me in this regarding?

thanks

[Oleg Komarov]

Which is already part of MATLAB: gplot().

Answer 1

[nanren888]

huda nawaf,

Interesting that the Mathworks copyright is still in the code you are using. It is not clear what is added to gplot by the addition.

gplot has an example in doc: try doc gplot

It seems as a graph has no inherent shape, that you must provide the xy points for each node for it. The example in doc shows a Buckyball node layout.

I've never used gplot before. I read the help, read doc gplot, played a few minutes & have this.

 x = 1:2;
 y = 1:3;
 [XX,YY] = meshgrid(x,y);
 a = (rand([2*3,2*3])>0.8);
 P=[XX(:),YY(:)];
 gplot(a,P,'-*');
 axis([0,7,0,7]);
 a
 P

a =

     0     0     0     0     0     1
     0     0     1     1     0     1
     0     0     1     1     0     0
     0     0     0     0     0     0
     0     0     1     0     0     1
     0     0     1     0     1     1

P =

     1     1
     1     2
     1     3
     2     1
     2     2
     2     3

Maybe it will help a little?

[huda nawaf]

thank,

but when see the figure can not see the node 1 connect with node 6, node 2 with node 3 and 4 and so on

[Walter Roberson]

Your earlier questions indicated that any outlay was acceptable. Are you now imposing restrictions about lines not overlapping, lines not crossing, or something like that?

[huda nawaf]

no walter, my erlier question is see the cluster visually. Now, I need see the nodes of adjacancy matrix how connect to each other.

that figure is not relate with the above matrix.

please, inform me how I can send image , then others see it. I think I sent image in previous time but nobody saw it.

thanks

[Walter Roberson]

http://www.mathworks.com/matlabcentral/answers/7924-where-can-i-upload-images-and-files-for-use-on-matlab-answers

Answer 2

[Walter Roberson]

If all you have is the adjacency matrix, then even if the weights of the vertices can be interpreted as distances, it is difficult to reconstruct a planar graph. Oh, algebraically it can be done, but it involves solving (N^2)/2 simultaneous non-linear equations, and that gets very time consuming extremely quickly.

So, you might as well just use rand() to generate random x and y coordinates and graph using those.

[huda nawaf]

what i need simple graph depending on adjacency matris like this image:

http://imageshack.us/photo/my-images/268/graphb.png/

thanks

[Walter Roberson]

random coordinates can do that.

[huda nawaf]

thanks walter, please show me how do that with random coordinates

[Walter Roberson]

xy = rand(NumberOfNodes, 2);

I suspect that likely NumberOfNodes = size(AdjacencyMatrix, 1);