Draw real graph (graphviz?)

I´m working with different graph algorithms, and for testing, and see the results, i need to visualize the graph.

I´m trying to use graphviz for visualization, but i dont want to use any Layout Engine, just use the real coordinate开发者_如何学Cs of the points.

For example: some TSPLIB instances have coordinates like: 1.54400e+04 8.88800e+03

Is this posible? should i use another tool?

Thanks in advance !

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Define the nodes like

nodename [pos="2,4!"];

to position them at (x=2|y=4) (the unit is inches).

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Try GoogleCharts http://code.google.com/apis/chart/